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[0001] This application claims priority to United States provisional application Ser. No. 62/200283 filed on Aug. 3, 2015, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to two-phase fingers to passively reorient objects while picking them up and thereafter grasping them securely.
[0003] Robotic research has long been interested in the ability to grasp and manipulate a large and varied set of objects. Due to stringent requirements on speed, precision, and reliability, the automation industry however has preferred simple gripping solutions that can accurately localize and securely grasp a small set of objects [1]. Furtherance, the need for object manipulation at assembly is often bypassed by specialized part feeders which present the parts in a pose suitable for picking and use.
[0004] Robotics research .has been driven, and is still driven in part today, by the needs of factory automation. The last two decades have seen a remarkable evolution of robotic manipulators leading to a precision of 30 microns, speeds of a few meters per second, the availability of force feedback and force control, as well as safety and compliance. Unfortunately, the lack of robust solutions for object manipulation has limited the role of these remarkable machines to mostly pick-and-place.
[0005] Getting an object in a fitting pose for an assembly, either by picking it up in the required pose or by regrasping it, is crucial for the success of the assembly. Often, the approach practiced in industry is to avoid the need for regrasping. An ancillary system deals with part feeding by singulating and locating a parts from a pile by passing them through specially designed pathways that reorient them and present them to the robot in an already suitable pose. This approach, although proven robust, impinges on important space, time, and set-up requirements, leading to huge costs in the set-up of a new assembly line. When the product changes, little of the set-up can be reused. These factors discourage the possibility of assembly automation for products with short upgrade cycle time.
[0006] The large market for automation of electronic product assembly and the demand from small scale industries for affordable automation are two major contributors to the rising interest in flexible automation. It aims for automation systems that are modular, easy to set up and adapt, and easy to integrate among human co-workers [23, 24]. Dexterity has been identified as one of the major roadblocks and essential capabilities needed to address the challenges in next-generation automation [25]. Rather than general-purpose dexterity, we explore a solution to perform a particular reorientation precisely and reliably, and with the ability to be easily adaptable to other parts and systems with minimal reconfiguration.
[0007] If is therefore an object of the invention to provide a two-phase gripper that allows reorientation of an object followed by secure grasping.
SUMMARY OF THE INVENTION
[0008] The two-phase gripper of the invention to reorient and grasp an object while being picked up includes a parallel jaw gripper including a pair of opposed, two-phase fingers, each finger including a cavity covered by an elastic strip, the elastic strip including a point contact. Closure of the jaws of the gripper on the object at a first, relatively lower force results in contact at lower friction between the point contact on the elastic strip on the ringers and the object allowing the object to rotate under gravity as the gripper is raised. Closure of the jaws of the gripper on the object at a second, relatively higher force causes the elastic strip to recede into the cavity resulting in multi-point contact with higher friction between the fingers and the object to securely grasp the object. In a preferred embodiment, the cavity is a V-shaped groove. Suitable objects for reorientation and grasping include cylindrical or prismatic shapes. In a preferred embodiment, the contact on the elastic strip may be cured rubber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of the gripper of the invention illustrating a V-groove cavity, elastic strip and point contact.
[0010] FIG. 2 is a plan view of the gripper of the invention illustrating the two phases of the gripper,
[0011] FIG. 3 a is a schematic illustration of the top view of an object in the cavity.
[0012] FIG. 3 b is a side view of an object in the cavity.
[0013] FIG. 4 is a schematic diagram illustrating the pivoting phase of the two-phase gripper.
[0014] FIG. 5 a is a perspective view of the two-phase fingers of the invention mounted on a gripper.
[0015] FIG. 5 b is another perspective view showing the two-phase fingers of the invention mounted on a gripper.
[0016] FIG. 6 is a graph of gripping force versus offset from center showing successful and failed pivoting experiments.
[0017] FIG. 7 is a graph of gripping force versus offset from center showing estimation of limits on the gripping force analytically for successful execution of pivoting.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] We present a novel design of two-phase fingers which eliminate the need for part feeders by grasping and passively reorienting a set of parts. Two-phase refers to a discrete change in the contact geometry between fingers and part as the gripping force increases, where the gripper function-switches from passive reorientation of the part to a secure grasp. In particular, this patent application focuses on grasping and reorienting cylindrical or prismatic parts, very frequent geometries in Industrial assembly settings [2]. We demonstrate how the two-phase gripper reorients cylindrical parts to an upright pose and grasps them securely in an uninterrupted and continuous motion.
[0019] FIG. 1 illustrates the two-phase finger in action. The design is composed of a small contact point 3 on an elastic strip 2 mounted over a V-groove cavity 1 . When an object is grasped with low gripping force, it pivots about the contact points on the strips until it aligns with gravity. As the gripping force increases, the elastic strips recede into the cavities, and the object sits into the V-grooves securing the grasp.
[0020] We demonstrate the design by instrumenting two commercially available grippers (2-Finger 85 from Robotiq, and WSG32 from Weiss Robotics) and testing them with three different object types. The experiments validate the effectiveness of the design in reorienting and securing the parts.
[0021] FIG. 1 shows that the design of the two-phase finger can be retrofitted to any common parallel-jaw gripper.
[0022] In this application we focus on a particular case commonly encountered in assembly operations—reorienting cylindrical parts from a horizontal pose on a table or a conveyor belt to an upright pose required for assembly. We focus on cylindrical parts which are one of the most common geometries within industrial assembly, with the goal of providing a reliable and fest method for picking, reorienting and securing.
[0023] The functional requirements of the gripper are as follows:
[0024] 1) Passive reorientation of a cylindrical object from a horizontal pose to an upright pose.
[0025] 2) Secure the grasp on the object in the new upright orientation.
[0026] The motion of a grasped object is governed by the kinematic and Motional properties of all contacts it makes. To let an object pivot under gravitational three, contacts must offer minimal Motional torque, characteristic of contacts with small area. On the other hand, to localize and to hold the object securely after it pivots, specific kinematic constraints and significant frictional resistance needs to be provided. The proposed design aims to fit both needs.
[0027] We rely on a built-in mechanism in the fingertips to change the finger-object contact geometry from point contact with low-friction to multi-point contact with high friction. The change on the contact geometry is triggered by the magnitude of the gripping force. The functionality is depicted in FIG. 2 . In the figure, an object 10 is first gripped with point contact to allow pivoting. Thereafter, as the jaws close on the object 10 the elastic strip 2 deforms and the cylindrical object 10 is securely grasped by the gripper.
[0028] The cavity 1 is meant to provide kinematic constraints that force the object to align to an upright pose, and later maintain that pose even when the robot or hand is freely moved.
[0029] This application focuses on cylindrical objects, and consequently a canonical V-groove gives an appropriate geometry for the cavity. Given the radius R of the cylinder to pick, we chose the values for the depth of the cavity H and its angle 2θ so that the fingers will not touch each other when holding the object. Otherwise the object would be able to move even with the gripper fully closed. We impose then:
[0000] H≦R/sin θ (1)
[0030] As illustrated in FIG. 3 , the expectation is that the kinematic constraints offered by the V-grooves will push the cylindrical object to the center of the cavity and make it vertical from anywhere within the groove. After the alignment, and when combined with friction from contacts within the V-groove, we get a force-closure grasp on the object [26].
[0031] The role of the elastic strip 2 is to facilitate the transition from a point contact to patch contact as the gripping force increases. At low gripping force, we would like the elastic strip 2 to provide high stiffness to maintain a point contact between fingers and object, and low stiffness as fee gripping force increases above certain threshold so that the snip recedes into the cavity and allows surface contact between the finger and the object However, practically achieving such “softening spring” behavior can be involved.
[0032] For the purpose of prototyping, we used a rubber band with a preload as the elastic strip. The required stillness value for the elastic strip is bounded by two constraints based on the desired application.
[0033] Let δ pivot be a maximum allowable deflection in the strip for the gripping force suitable for pivoting the object F pivot . This gives a low bound on the stiffness of the strip (K).
[0000] K≧F pivot /2 δ pivot (2)
[0034] Similarly, let δ grasp be the minimum deflection needed in the strip when the object is held in the V-groove cavities giving an upper bound on the stiffness of the strip.
[0000] K≦F grasp /2 δ grasp (3)
[0000] where δ grasp =2H (1−sinθ)/cosθ is the minimum extension needed in the strip so that it can recede and sit in the cavity and F grasp is the high gripping force applied for grasping the object. F grasp is limited by the maximum grasping force the gripper can apply.
[0035] We will proceed under the assumption that as long as the stiffness of the strip satisfies ( 2 ) and ( 3 ), the variation in the stiffness does not affect the functionality of the gripper, and that the stiffness of the strip remains constant throughout the operation.
[0036] The role of the point contact 3 on the elastic strip 2 is to act as a hinge to support and allow minimal frictional resistance to the rotation of the object in the fingers under gravity. Though ideally we want point contacts between the object and the lingers for pivoting, in reality they are patch contacts with small area.
[0037] We now explain a typical operation for the two- phase gripper. The complete manipulation task can be broken down into the following steps:
1) The two-phase gripper reaches over a cylindrical object lying on a flat surface with its longitudinal axis horizontal. 2) The fingers hold the object offset from the center of mass with a low gripping force, just sufficient to prevent the object from slipping. 3) The object is raised, while it pivots about the axis between the finger contacts, until it is completely lifted from the surface and aligned upright in the gripper. 4) The grip on the object is tightened, which passively shifts the cylinder to the center of the cavity and secures the grasp.
[0042] We analyze now the mechanics of the pivoting manipulation and the criterion to select an appropriate value for the gripping force. FIG. 4 shows the schematic of a cylinder 10 being grasped and lifted.
[0043] The gripping force plays a key role in determining the success of the pivoting operation. It must suffice to prevent slipping of object, but needs to be small enough to allow pivoting under gravity. In order to lift the object without slipping, the linear frictional force at the finger contacts must balance the gravitational force. This determines lower bound on the gripping force during the pivoting phase:
[0000] F pivot ≧Mg/μ (4)
[0000] where M is the mass of the object, g is the gravitational acceleration and μ is the linear coefficient of friction at the finger contacts.
[0044] The upper bound on F pivot is determined by the limit on the Motional resistance to allow pivoting, which to a large extent is determined by the size of the contact area between the part and fingers. Following, we compare two different approaches to estimate the upper bound, first with idealized point contacts and second with more realistic small patch contacts.
[0045] An idealized point contact with friction can transmit forces along three linear dimensions, one along the contact normal and mo along the contact plane, in the ideal case, it does not offer any torsional resistance at contact [26].
[0046] This means that, as long as there is an offset between the center of gravity (CG) of the object and the finger contact locations, for any positive value of the gripping force, the object is tree to pivot about the fingertips under the effect of gravity. Effectively, there is no upper bound on F pivot .
[0047] In practice, it is hardly possible to get point contacts. There is always a finite surface area at contacts that can provide some degree of torsional resistance.
[0048] We assume those contacts to be planar patches. A planar contact with friction can transmit a torque about the contact normal in addition to the forces along three directions as In the previous case. That torque, specially when an object is picked close to the center of gravity with high force, can counterbalance the gravitational torque and prevent the part from pivoting, which can cause problems.
[0049] The simplest approximation to capture torsional friction is to model a patch contact as a point contact that transmits a torque about that point with a certain torsional coefficient of friction (μ tors ), producing the frictional torque μ tors F pivot . This model is often known as soft contact model [26]. However, estimation of μ tors is not trivial and in general depends on the contact geometry, so needs to the updated when the contact geometry changes.
[0050] There are more involved ways to model patch contacts. A model commonly used in manipulation planning is the limit surface model [27]. There are other models that are based on finite element approximations [28] which do not assume explicit knowledge of the torsional friction coefficient.
[0051] The focus of this invention is the mechanical, design of the two-phase fingers, and for the sake of simplicity, we will assume contacts to be circular, and finitely approximate them as a rigid set of point contacts forming a polygon concentric with the circular patch. The total frictional torque on the object can then be approximated as:
[0000] τ fric =μrF grip (5)
[0052] where F grip is the gripping force and r is the radius of the circular patch contact.
[0053] For an object to rotate in the fingers, the frictional torque created at the finger contacts must be smaller than the moment created by the gravitational force on the object, τ fric ≦MgLcosφ, which sets an upper bound on the gripping force:
[0000] F pivot MgL cosφ/μ r (6)
[0000] where L is a moment arm, the offset between the CG of the object and the fingertip location, and φ is the angle between the axis of the cylinder and the horizontal plane. φ changes from 0° to 90°as the object pivots from the horizontal pose to the upright pose. Though the moment arm reduces as the object slowly pivots, the inertia gained by the object can help it to pivot as the the moment approaches zero. So, we only check if the following constraint holds true when the part is in the horizontal configuration:
[0000] F pivot ≦M gL/μr (7)
[0054] In summary, constraints (1)-(7) collectively define the geometry of the V-groove cavity, stillness of the elastic strip over it and foe limits on the gripping force to pivot the object about the finger contacts.
[0055] We now discuss the experimental validation of the effectiveness of the two-phase fingers. In particular we focus on the validation of the small patch models for the linger contacts and the effect of changes in the grasping location on the required gripping force for pivoting.
[0056] For prototyping, we used 3D printed fingers with a V-groove cavity, and a rubber band with preload for the elastic strip. The point contact on the strip is-made by placing a drop of liquid rubber on the strip and then curing it The elastic strip is held in place using a cap screw.
[0057] We attached these lingers to two different grippers: Weiss Robotics WSG-32, with force feedback and force control, and the Robotiq 2-Finger 85 without force control. See FIG. 5 a. Both the grippers were mounted on an ABB IRB 140 industrial manipulator. We chose three different cylinders with different diameters and materials and one with a square flange, as our test objects.
[0058] FIG. 5 b shows a typical experimental setup with two of the test objects, the two-phase gripper and the manipulator. For every experimental trial, we lifted the object from the ground with a low gripping force in a range suitable for pivoting the object and then grasped it tightly after it is fully lifted from, the ground. The attempt is counted as a success if the part is reoriented to an upright pose without slipping and securely held in the V-groove at the end of the procedure. We conducted this experiment for multiple gripping forces, and at multiple gripping locations along the length of the cylinder, for all the tested objects. FIG. 6 shows the results of those experiments for one of the objects, and for comparison, FIG. 7 shows our expectation from the discussed pivoting models.
[0059] As discussed above, we approximate the contacts between an object and the fingertips by small patch contacts which offer small but non-negligible frictional torque about the contact normal To let the object pivot between contacts, the gripping force must satisfy constraint ( 7 ).
[0060] As we pick an object farther away from its center of gravity, the moment arm L increases making the range of compatible gripping forces for pivoting bigger.
[0061] We conducted a series of experiments of picking up a cylindrical object at varying offset distances from the center with different gripping forces. FIG. 6 shows the outcome of the experimental trials. The run is counted as a success if the object pivoted under gravity without slipping, and a failure otherwise. Due to the limitations of the gripper used, we limited the range for the gripping forces to the region 5 N-3 N The FIG. shows the increase in the valid gripping force region as the object is grasped farther away from the center.
[0062] FIG. 7 shows the estimation of the limits on the gripping force found analytically for successful execution of pivoting. The analytical model used here assumes circular patch contacts of 3 mm diameter at the fingertips, which give a good match for the fingers used. To evaluate the coefficient of friction between the object and the fingers, we made rigid fingers with the same rubber material at the tips. We picked the desired object and attempted to push it linearly in the grasp. Based on the gripping force and pushing force data generated from multiple experiments the linear coefficient of friction for the finger-object pair is estimated to be 0.6.
[0063] Following the ‘no slip’ criterion governing the minimum force at the fingers ( 4 ) and ‘minimal torsional resistance’ criterion governing the maximum force ( 7 ), we calculated the bounds on the gripping force which are shown in FIG. 7 . They are overlapped with the regions of success and failure trials observed during the experiments. Close resemblance of analytical and experimental results show that, given the mass of the object and the coefficient of friction between the fingers and the object, we can model the process well enough to predict the gripping force required to successfully operate the two-phase gripper.
[0064] This patent application has disclosed the design of a two-phase gripper, composed of a standard parallel-jaw gripper instrumented with special fingers capable of passively reorienting and securely holding a set of objects. The contact geometry between the fingers and the object changes from a point contact, which allows reorientation through pivoting, to a multi-point contact, which secures the grasp in the new orientation, as the gripping force increases. We focus on the application of the two-phase gripper to reorientation of cylindrical objects from a horizontal to as upright pose and then securely grasping them.
[0065] The two-phase fingers disclosed herein can be retrofitted to any parallel-jaw gripper of an appropriate size. The Idea of two-phase fingers can be easily extended to different shapes of objects by reconfiguring the cavity in the fingers.
[0066] The numbers in square brackets refer to the references listed herein. The contents of all of these references are incorporated herein by reference in their entirety.
[0067] It is recognized that modifications and variations of the present invention will be apparent to those of ordinary skill in the art and it is intended that all such modifications and variations be included within the scope of the appended claims.
REFERENCES
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[10] N. J. Nilsson, “Shakey the robot,” SRI Int, Tech. Rep. 323, 1984.
[11] M, Erdmann and M. T. Mason, “An exploration of sensorless manipulation,” in IEEE Int Conf. on Robotics and Autom. , vol. 3, April 1986, pp. 1569-1574.
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[13] K. M. Lynch and M. T. Mason, “Stable pushing: Mechanics, control-lability, and planning,” Int J Robot Res , vol. 15, no. 6, pp. 533-556, 1996.
[14] A. Rao, D. Kriegman, and K. Goldberg, “Complete algorithms for feeding polyhedral parts using pivot grasps,” IEEE Trans. on Robotics and Autom ., vol. 12, no. 2, pp. 331-342, 1996.
[15] N. Chavan Dafle, A. Rodriguez, R. Paolini, B. Tang, S. Srinivasa, M. Erdmann, M. Mason, I. Lundberg, H. Staab, and T. Fuhlbrigge, “Extrinsic dexterity: in-hand manipulation with external forces,” in IEEE Int Conf. on Robotics and Automation, 2014.
[16] A. Holladay, R. Paolini, and M. T. Mason, “A general framework for open-loop pivoting,”in IEEE Int Conf on Robotics and Autom., 2015.
[17] F. Wilson and J. Holt, Handbook of Fixture Design . McGraw-Hill, 1962.
[18] H. Asada and A. By, “Kinematic analysis of workpart fixturing for flexible assembly with automatically reconfigurable fixtures,” IEEE Journal of Robotics and Autom. , vol. 1, no. 2, pp. 86-94, June 1985.
[19] D. Blanding, Exact Constraint: Machine Design Using Kinematic Principles . ASME Press. New York, 1999.
[20] K. Lakshminarayana, “Mechanics of form closure,” Technical Report 78- DET -32, ASME, 1978.
[21] F. Reuleaux, The Kinematics of Machinery: Outlines of a Theory of Machines . Macmillan, 1876.
[22] A, Rodriguez and M. T. Mason, “Effector form design for 1dof planar actuation,” in IEEE Int Conf. on Robotics and Autom., 2013, pp. 349-356.
[23] S. Kock, T. Victor, B. Matthias, H. Jerregard, M. Kallman, L Lursdberg, R. Mellander, and M. Hedelind, “Robot concept for scalable, flexible assembly automation: A technology study on a harmless dual-armed robot,” in IEEE Int Symp. on Assent and Manuf. , May 2011, pp. 1-5.
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[27] S. Goyal, “Planar sliding of a rigid body with dry friction: limit surfaces and dynamics of motion,” PhD Dissertation, Department of Mechanical Engineering, Cornell University, 1989.
[28] P. R. Sinha, “A Contact Stress Model for Determining Forces in an Equilibrium Grasp,” University of Pennsylvania Dept. of Computer and Information Science Tech Report No. MS - CIS -90-19, 1989.
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Two-phase gripper. The gripper reorients and grasps an object while being picked up, The gripper Includes a parallel jaw gripper including a pair of opposed, two-phase fingers, each finger including a cavity covered by an elastic strip wherein the elastic strip includes a point contact. Closure of the jaws of the gripper on as object at a first relatively lower force results in contact with lower friction between the point contact on the elastic strip on the fingers and the object allowing the object to rotate under gravity as the gripper is raised. Thereafter, closure of the jaws of the gripper on the object at a second relatively higher force causes the elastic strip to receded into the cavity resulting in multi-point contact with higher friction between the fingers and the object to securely grasp the object. In a preferred embodiment, the cavity is a Y-shaped groove and the object is cylindrical or prismatic.
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TECHNICAL FIELD
This invention relates to the field of masks, and more specifically those masks which are used to administer a gas, such as oxygen, to a patient, particularly when a naso-gastric intubation procedure is to be accomplish simultaneously.
BACKGROUND OF THE INVENTION
The administration of gas, and particularly oxygen, to a patient is often lax and/or unsatisfactory. The administration, regulation, and efficiency are very poor since a relatively unknown volume of oxygen is delivered to the patient. For the most part, a simple oxygen mask or a nasal cannula of one type or another is normally used for the routine administration of oxygen.
A wide variety of oxygen masks have been available, varying in construction, style, and material, depending upon the specific purpose for which each is desired to be employed. Until recently, most masks were made of rubber. As a result of the need to provide a mask which is inexpensive, requires little storage space, need not be sterilized, and can be disposed of after each use to minimize contamination, most oxygen masks presently in use are made of plastic.
The basic mask which is available today uses neither a valve nor a reservoir bag. Exhaled air from the lungs of the patient is usually vented through holes in the body of the mask. In view of its convenience and relative comfort, the basic mask is widely used whenever moderate oxygen concentrations are desired for short periods of time. This might occur, for example, during the postoperative recovery state of a patient. Such a mask might also be used, for example, during either temporary or interim therapy when a patient is being weaned from continuous oxygen administration.
Most masks available today are relatively crude, causing a prediction of the exact volume of oxygen delivered to the patient to be impossible. However, it is known that the delivered concentrations vary from 35% to 55%, at gas flow rates of 6 to 10 liters per minute.
The nasal cannula is an appliance which normally includes two tips which extend from an oxygen supply tube and are inserted into the nostrils of a patient. The cannula can be held in place by head straps or by bows that hook over the ears, in the manner of eye glasses.
Unfortunately, the cannula suffers from the disadvantage of being instable, i.e., it is easily dislodged from a restless or unobservant patient. While a doctor or nurse making medical rounds might note that an oxygen flow meter is open, he or she might not notice that the cannula is so twisted out of place that the patient could not get any significant amount of oxygen.
The cannula also suffers from the disadvantage that it is often necessary to pay attention to a patient's comfort when instituting oxygen treatment. An excessive flow rate of oxygen, the definition of which varies according to the patient, can produce a considerable amount of pain in the frontal sinuses of the patient. Also, such nasal pathology as a deviated septum, mucosal edema, mucus drainage, and polyps may interfere with a patient's oxygen intake.
In those cases in which a naso-gastric tube might be used together with the nasal cannula, the utility of the latter is further degraded. In addition to dislodgement problems, the combined affect of the two tubes placed in one nostril creates a physical irritant to the delicate mucosal tissues of the nasal passage and sinuses. Such irritation often takes the form of ulcerative lesions. Since a decreased volume of oxygen is often experienced during the use of the two tubes, the normal procedure is to increase the rate of oxygen flow. However, that often results in the desiccation of tissues, further traumatizing them, causing severe frontal sinus pain and various pathalogic results.
Consequently, it is believed that the basic oxygen mask having a body which is pressed against the face of the patient is far superior to the nasal cannula for the application of oxygen. Nevertheless, such masks suffer from the disadvantage that, in many postoperative and related cases, a naso-gastric intubation procedure is necessary. In such a case, plastic tubing is usually inserted into the patient's nasal passageway and guided down the esophagus into the upper gastric area. This tubing is an obstruction, as far as the administration of oxygen is concerned, and complicates the application of the mask or the cannula.
If, today, a naso-gastric tube and an oxygen mask are to be used simultaneously, the tube is put in place first and the mask is then applied. The seal of the mask against the face of the patient is incomplete due the protrusion of the tube at the point that the tube intersects the body of the mask. In other words, it is impossible to conform the mask to the facial configuration of the patient and, in many cases, the mask is generally askew. Such incorrect seating of the mask allows oxygen to freely pass to the atmosphere, resulting in treatment of the patient with a decreased and uncontrolled volume.
Additionally, the stability of the mask as well as the patient's comfort are complicated by the tube. The mask is much less secure and more easily dislodged by an unobservant, restless, or mobile patient. Also, the tube is usually placed across and secured to the facial skin in an attempt to prevent relative movement among the patient, tube, and mask. The taping of the tube to the skin often produces discomfort and runs the risk of producing a pressure necrosis of the skin.
An example of a prior art mask which may be used together with a naso-gastric tube in the manner described above has been illustrated in U.S. Pat. No. 3,357,426 to Cohen. The drawings of that patent clearly depict the manner in which the naso-gastric tube is located on the face of the patient in such a manner as to prevent a complete seal about the edge of the mask body, rendering the mask less stable on the face of the patient.
On the other hand, U.S. Pat. No. 3,809,079 to Buttaravoli discloses a combined resuscitation mask and airway for ventilation of a patient's lungs in a positive and reliable manner. However, that disclosure includes a rigid body which may extend down the throat of the patient; it does not relate to a structure which would facilitate a naso-gastric intubation.
Consequently, a need currently exists for a oxygen-administration device which may be simultaneously employed with a naso-gastric tube in such a manner that the volume of oxygen can be controlled at least to the same extent as may be attained with a fully seated oxygen mask.
SUMMARY OF THE INVENTION
The present invention relates to an oxygen mask which may be employed in the well-known manner. Such a mask is produced, for example, by Ideal Medical Products of Lansing MI. A mask which can be utilized with the present invention may be of any desired size, configuration, etc. Preferably, the mask is relatively pliable, such as might be the case with a soft, clear vinyl, and easily adaptable to the facial contours of the patient in order to provide sealing throughout the periphery of the mask body where it contacts the skin of the patient.
More specifically, the present invention relates to such a mask which is adapted to particularly provide for the passage of a tube therethrough, such as that which might be employed in a naso-gastric intubation procedure.
The present invention, which may be employed in a wide variety of embodiments, basically comprises a fenestration in the wall of the mask body. When a tube is not in place in the fenestration, the latter will be substantially closed so as to minimize or completely prohibit any escape therethrough of oxygen from the interior of the mask body.
In the presently preferred embodiment, the fenestration may be provided adjacent to and extending through the sealing portion of the mask. The fenestration may be located at any desired position about the periphery of the mask so that a tube may be so arranged as to be substantially and comfortably aligned with the nostril of the patient.
The fenestration may be of any desired size and configuration. In many cases, however, it will be preferred that the fenestration be of such a configuration that it will firmly hold the naso-gastric tube in place without allowing relative movement between the tube and the mask. In some embodiments, it is currently preferred that the fenestration be provided with some type of lining material or other structure which will provide a form of seal, either about the tube, or across the fenestration itself so that the opening is sealed when a tube is not in place. The invention allows this type of mask to be used with or without a naso-gastric tube, with little or no difference, in the placement of the mask and the availability of the oxygen to the patient.
Upon review of the following Detailed Description, taken together with the accompanying drawings, those skilled in the art will realize that the present invention may be employed in a wide variety of embodiments, many of which may not even resemble those described and depicted here. Nevertheless, it should be borne in mind that that the description and accompanying drawings are merely illustrative of the principles of the present invention and only set forth the best mode presently contemplated for accomplishing the invention. They are not intended to delimit or restrict the scope of the invention which is defined and limited only by the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 comprises an isometric illustration of a mask formed in accordance with the present invention, depicting the use of a fenestration in the wall of the mask;
FIG. 2 comprises a top plan view of the mask depicted in FIG. 1 depicting a fenestration on each side of the mask;
FIG. 3 comprises a side elevation view of the mask depicted in FIGS. 1 and 2;
FIG. 4 comprises an elevation view of the bottom end of a second mask embodiment formed in accordance with the present invention, illustrating a single fenestration in the base end of the mask;
FIG. 5 comprises a sectional plan view of the mask shown in FIG. 4, as seen along a line V--V therein; and
FIGS. 6-15 depict various shapes and configurations of fenestrations which may be employed in a facial mask in accordance with the present invention.
DETAILED DESCRIPTION
Referring now to FIG. 1 in greater detail, a mask 11 is shown including a body 13 which surrounds an internal cavity. The body 13 may be placed over the nose and mouth of a patient so that the patient may inhale and exhale into the mask cavity. The periphery of the body 13, at the open edge of the cavity, is preferably surrounded by a sealing surface 15 which may be placed against the patient's face to prevent the passage of gas or oxygen in or out of the mask cavity except through preselected passages. In the current state of the art, the mask body 13 and sealing lip 15 are preferably constructed of transparent, thin, pliable plastic which is relatively inexpensive. Consequently, the mask readily conforms to any patient's face. It can be easily used and then disposed of without risking cross-contamination of patients, requiring cleaning between uses, etc.
If desired, the upper portion of the mask may be provided with a pliable nose piece 17 which may be bent to generally conform to the nose of the patient. The nose piece assists in holding the mask in place and keeping it sealed against the patient's face. Similarly, the mask may be provided with a band, strap or earpiece in order to hold the mask to his face.
In the particular type of mask illustrated, a relatively rigid inlet connection device 21 may be fixedly attached to the mask body 13 for receipt and support an oxygen or other gas hose 23. Thus, oxygen can be fed through the hose 23 into the mask 13 through the connector 21 for increasing and controlling the oxygen intake of the patient. In order to allow the exhaled breath of the patient to be exhausted from the mask, one or more aperatures 25 may be provided in either or both sides of the mask.
As described thus far, such masks are currently readily available and constitute prior art, of which this invention is an improvement.
As seen in FIG. 1, the mask may be provided with a cleft or fenestration 31, through which a naso-gastric tube 33 may pass and within which it may be secured. Of course, those skilled in the art will realize that, as shown in FIG. 2, two clefts or fenestrations may be provided for the passage of a like number of naso-gastric tubes. In any event, it is preferred that the cleft or fenestration 31 be so positioned as to allow comfortable and convenient aligned of a tube 33 with the nostril of a patient so that the use of the mask and the naso-gastric tube will not conflict with one another in servicing the patient.
In the embodiment illustrated in FIG. 1, the fenestration 31 is shown shaped in a form similar to a "key hole" 35 having a foam rubber or other flexible lining 37 which may be split down the middle for insertion and receipt of the tube 33. The lining and the central slit or opening therein preferably extend down to and through the sealing portion 15 of mask 11. Consequently, proper selection of the liner 37 will allow the slit to remain substantially closed throughout the entire length of the fenestration 31 when a tube, such as that illustrated at 33, is not in place. On the other hand, when the tube 33 is installed, the lining 37 will closely surround the tube and be substantially closed throughout its length for the remainder thereof.
As a result, such a fenestration will produce a significant advancement in the technology of therapeutic application of oxygen simultaneously with the use of a naso-gastric tube. The volume of oxygen applied will be relatively precise in accordance with the orders of the doctor to the medical personnel.
In use, the naso-gastric tube would be applied to a patient in the well-known manner. The mask may then be placed in position against the face of the patient. The cleft or fenestration 31 may be manually split and pushed over the tube 33 until the tube is located in the upper portion of the slit or opening. Thus, the tube may be substantially sealed and firmly seated in the upper portion of the key hole-shaped opening and the mask will remain sealed against the face of the patient.
Referring now to FIGS. 4 and 5, an alternate embodiment of the device shown in FIGS. 1-3 has been illustrated. In that embodiment, the fenestration 41 may comprise a slit formed in the bottom portion of the mask and extending upwardly from the sealing 15 to a location intermediate the seal and the connector 21.
A rib 45 may be formed integral with or suitably attached to the body 13 about the vicinity of the slit, thus preventing stress, imposed when the tube is installed, is in place, and/or is removed, from damaging the mask. Thus, with this embodiment, the edges of the slit, i.e., the adjacent portions of the mask body 13, will form a pair of flaps 47 and 49 which are normally closely adjacent one another to seal off the fenestration.
When the mask is placed over a tube 33, the fenestration may again be manually split and pushed over the tube. When the tube reaches the upper portion of the split, it will thus be seated and substantially sealed therein. The fenestration may then be closed so that the flaps 47 and 49 are as close together as possible. As a result, the naso-gastric tube can be properly positioned and will not move about if the patient should be become restless or mobile. At the same time, the mask will continue to be sealed against the patient's face at all times to provide the optimum sealing effect. Any oxygen loss through the fenestration slit between flaps 47 and 49 will be minimal since any separation therein will be relatively small.
Referring now to FIGS. 6-15, it can be seen that a wide variety of shapes, sizes, etc., of clefts or fenestrations may be employed, realizing that they may be used singly or in pairs and at any convenient location in the mask so as to properly hold the naso-gastric tube in a convenient and comfortable location for the patient.
In FIG. 6, for example, it can be seen that the mask body 13 may be provided with a fenestration 61 having a slit 63 therein and a reinforcing wall or rib 65 spaced from the rib a convenient distance for allowing the insertion and position maintenance of a tube (not shown). In this illustrated embodiment, the fenestration 61 may be formed in a shape resembling a crook of a sheppard's staff. Consequently, when the mask is installed over the tube, the latter may be moved into the inner end of the slit to provide substantial sealing of the tube and also to firmly ensure that it is properly seated and held in place.
If desired, of course, the internal end portion of the fenestration 61 may be enlarged so as to provide an opening of substantially the same size as that for the cleft 31 shown in FIG. 1. Also, it will be realized by those skilled in the art that the slit 63 may be formed in the wall of the body 13 similarly as shown in FIG. 5, or it may be provided between opposed edges of a foam rubber liner, similar to that structure shown in FIG. 1. In either case, the slit will be substantially closed with the tube in place, again minimizing inadvertant oxygen loss.
Referring now to FIG. 7, a fenestration 71 is illustrated having a slit 73 for receipt of a naso-gastric tube. The vicinity of the slit 73 may be substantially surrounded and strengthened by a rib or wall 75 of substantially circular configuration. Thus, with the tube in place, the fenestration may be manually split, such as by pulling one side away from the mask cavity and pushing the other side into the cavity, may then be gently pushed down over the tube. When the tube is substantially surrounded by the rib 75, the opposite sections of the cleft 71 may be realigned, thus holding the tube in place with a substantial seal about the periphery thereof through the actions of flaps 77 and 79. Once again, flaps 77 and 79 may be part of the wall of mask body 13 or they may be separate, attached elements.
If desired, this fenestration may be held in the closed position during use, such as by means of a suitable clasp 74 which may include one or more protrusions 76 and a cross-piece 78. Alternatively, the protrusions may be used to located and hold a small rubber band or similar element to hold the fenestration closed. Although shown only in this embodiment, those skilled in the art will readily realize that such a positive closure may be used with any fenestration.
Another embodiment of a fenestration is illustrated in FIG. 8 at 81. In this instance, a strengthening rib or wall 85 may be provided on opposite sides of a pair of flaps 87 and 89. The flaps may either be integral with the wall of the body 13 or specifically attached thereto. In any event, each flap may be provided with a square side edge so that the flaps normally overlap. Alternatively, the slit 83 may be formed by cutting the portion of the wall 13 below the rib 85 on an acute angle or bias relative to the surface of the wall. Thus, when the flaps 87 and 89 are aligned, the opposed surfaces of the slit, which are at an identical acute angle relative to the wall 13, will abut one another and serve to seal the fenestration.
When it is desired to use such a mask with a naso-gastric tube, it is only required that the medical personnel gently push the mask down over the tube. Thus, the tube will be substantially sealed in place and the mask will still fit closely against the face of the patient without undue loss of oxygen.
As shown in FIG. 9, a fenestration 91 may be provided of substantially rectangle configuration having a slit 93 bounded by a rib or wall 95. In this instance, the slit is illustrated as having a squared edge between opposed flaps 97 and 99, although those skilled in the art will realize that a biased slit could also be provided in the manner of that illustrated in FIG. 8. Alternatively, the flaps 97 and 99 could be slightly enlarged so that the adjacent edges thereof overlap to provide a more positive sealing when a tube is not in place.
Once again, when a fenestration such as that at 91 is to be employed, it is simply necessary to install the tube and then push the mask down over the tube so that it is sealed by the flaps 97 and 99 for minimal oxygen loss.
Referring now to FIG. 10, a fenestration 101 may be provided with a slit 103 bounded by a strengthening rib or wall 105 resembling an inverted, truncated triangular configuration. With this structure, when the mask is to be applied over the tube, the opposite ends of the slit adjacent the sealing edge of the mask may again be manually split and the tube gently pushed over the mask. The ends may then be manually realigned to hold the tube in place and substantially seal it to achieve the desired result.
The fenestration 111 illustrated in FIG. 11 is shown as comprising a slit 113 bounded by a rib 115 having two legs which meet at an acute angle, i.e., resembling two legs of an isosceles triangle. Consequently, when a mask using this type of cleft is pushed down over a tube, opposed flaps 117 and 119 will part and allow the tube to be substantially sealed in position while the mask is still sealed to the face of the patient throughout the remainder of its periphery.
A still further embodiment of a fenestration is illustrated at 121 in FIG. 12. In this illustration, a multisided polygonal rib 125 may provide the external boundary for a plurality of flaps 127 which are separated by slits in the wall material of the body 13. Preferably, the number of flaps is equal to or greater than the number of sides of the polygon. Thus, this mask may be employed by manually misaligning the opposite edges of the fenestration adjacent the sealing lip 15 and pushing the mask down over the tube. The flaps 127 will part along the slits at their respective edges, allowing the tube to be held in place and substantially sealed when the opposite edges of the fenestration are again realigned.
As shown in FIGS. 13 and 14, in some instances it may be desired to provide an open fenestration such as the ovoid configurations illustrated at 131 or that illustrated at 141. The opening 134 or 144 may be provided with a generally oval-shaped ridge 135 or 145, respectively. Such masks may also be applied by temporarily misaligning the opposite edges of the fenestration adjacent the sealing lip and then realigning them after the mask is pushed over the tube. It will often be preferable to use structures such as those shown in FIGS. 13 and 14 when the shape of the open fenestration is substantially identical to that of the tube to be used, thus allowing the tube to be sealed against the rib or wall of the fenestration and also be held in place by the alignment of the lower portions of the fenestration against the sealing lip 15.
Of course, those skilled in the art will realize that a cleft or fenestration such as those found in this disclosure may be provided with any kind of sealing means or structure which substantially seals and holds the mask in a fixed relationship with the naso-gastric tube. As shown in FIG. 15, for example, a key hole-type fenestration 151 may be provided with a rib 155 which abounds an opposed pair of overlapping flaps 157 and 159. Thus, as illustrated, it is not necessary that the flaps meet one another along a single, clean line. It is only necessary that the fenestration be substantially closed when a naso-gastric tube is not in place in the patient and also substantially closed and sealed about the tube when the patient is undergoing naso-gastric intubation and oxygen therapy simultaneously.
As a result of a review of the various embodiments of this imvention, it should now be apparent to those skilled in the art that the oxygen mask fenestration or cleft which may be utilized with any particular tube or similar devices may be of any desired size or shape, depending only upon the particular apparatus which is extend therethrough. Similarly, any suitable sealing device may be employed in the fenestration, including opposed flaps, a liner, or a reasonably close tolerance fit between the tube and the rib which strengthens the opening. Also, even simpler embodiments may be employed.
For example, the mask body 13 might simply be provided with an aperture through which a tube may extend in reasonably close relationship. For tube installation purposes, a slit may extend from the aperture through the sealing lip 15. As packaged or used without a tube, the aperture and slit may be closed or covered by a small piece of tape which can be manually removed when necessary. When a tube is in place within the aperture, the slit may be retaped to close it, strengthen the mask (particularly if no rib such as that at 45 is used), and hold the tube in place.
Having now reviewed this Detailed Description and the drawings of the presently preferred embodiment, those skilled in the art will realize that these merely define a presently preferred embodiment of the invention instead of delimitating it. Rather, it must be kept in mind that the scope of the invention, as set forth below, is broad enough to encompass a substantial number and wide variety of embodiments, many of which may not even resemble that depicted and described here. Nevertheless, such additional embodiments will employ the spirit and scope of the invention which is established only by the following claims.
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A mask for delivery of gas, such as oxygen, to a patient and useable in a naso-gastric intubation procedure without disruption of the seal between the mask and the face of the patient. The body of the mask includes a fenestration or opening through which the naso-gastric tube may be inserted. The fenestration is preferably shaped to support the tube in manner which is comfortable for the patient and which eliminates or minimizes the amount of gas lost to the atmosphere outside the mask. In at least some embodiments, the fenestration is closed when a tube is not inserted therethrough so that the mask may be used normally without loss of the gas through the fenestration.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. §119(e)(1), to U.S. Provisional Application Ser. No. 61/394,133, filed on Oct. 18, 2010, the entire contents of which is incorporated herein.
TECHNICAL FIELD
This disclosure relates to medical implants having a tie layer including magnesium or a magnesium-based alloy.
BACKGROUND
A medical implant can replace, support, or act as a missing biological structure. Examples of medical implants include orthopedic implants, bioscaffolding, and endoprostheses such as stents, covered stents, stent-grafts, bone screws, and aneurysm coils. A medical implant can also add a new function to the body. For example, medical implants can include identification tags, communication devices, and/or pacemaking electrodes.
Endoprostheses can be implanted in various body passageways such as arteries, other blood vessels, and other body lumens (e.g., neural pathways). These passageways sometimes become occluded or weakened. For example, the passageways can be occluded by a tumor, restricted by plaque, or weakened by an aneurysm. When this occurs, the passageway can be reopened or reinforced, or even replaced, with an endoprosthesis. An endoprosthesis is typically a tubular member placed in a lumen in the body.
Endoprostheses can be delivered inside the body by a catheter. The catheter supports the endoprosthesis in a compacted or reduced-size form as the endoprosthesis is transported to a desired site. Upon reaching the site, the endoprosthesis is expanded, for example, so that it can contact the walls of the lumen.
The expansion mechanism can include forcing the endoprosthesis to expand radially. For example, the expansion mechanism can include the catheter carrying a balloon, which carries a balloon-expandable endoprosthesis. The balloon can be inflated to deform and to fix the expanded endoprosthesis at a predetermined position in contact with the lumen wall. The balloon can then be deflated and the catheter withdrawn.
In another delivery technique, the endoprosthesis is formed from an elastic material that can be reversibly compacted and expanded, e.g., elastically or through a material phase transition. During introduction into the body, the endoprosthesis is restrained in a compacted condition. Upon reaching the desired implantation site, the restraint is removed, for example, by retracting a restraining device such as an outer sheath, enabling the endoprosthesis to self-expand by its own internal elastic restoring force.
Endoprostheses can sometimes carry a drug, such as an antiproliferative, to reduce the likelihood of restenosis, i.e., reclosure of the vessel due to immune reactions by the body at the treatment site. For example, a drug-eluting layer can be coated onto an endoprosthesis.
SUMMARY
A medical implant having a metallic base, a tie layer, and at least a first layer overlying the tie layer is described herein. The tie layer is bonded to at least a portion of a surface of the metallic base. The tie layer includes magnesium or a magnesium-based alloy. The tie layer has an outer surface including dendritic grains. The first layer overlies the outer surface of the tie layer.
The metallic base can include a biostable metal. For example, the metallic base can include a metal selected from the group consisting of stainless-steels, platinum-enhanced stainless steels, cobalt-chromium alloys, nickel-titanium alloys, niobium-based alloys, titanium-based alloys, and tantalum-based alloys. In other embodiments, the metallic base can include a bioerodible metal (e.g., iron or a bioerodible iron alloy). The metallic base, in some embodiments, includes a metal having a melting temperature greater than the melting temperature of the magnesium or the magnesium-based alloy of the tie layer. For example, the metallic base can include a metal having a melting temperature of 700° C. or greater.
The dendritic grains, in some embodiments, have a maximum dimension of between 10 microns and 50 microns. The dendritic grains can protrude from the tie layer, providing a rough outer surface.
In some embodiments, the tie layer includes pure magnesium. In other embodiments, the tie layer includes a magnesium-based alloy. The magnesium-based alloy can include zinc, aluminum, calcium, tin, rare earth metals, or a combination thereof.
The tie layer can further include particles within a matrix of the magnesium or the magnesium-based alloy. The particles can partially protrude from the surface of the tie layer, in order to provide a rough outer surface. The particles can have a maximum dimension of between 10 microns and 50 microns. The particles can be iron particles, calcium powder, graphite spheres, graphite nanotubes, barium powder, or a combination thereof. In some embodiments, the particles are bioerodible.
The tie layer, in some embodiments, has an average thickness of between 1 micrometer and 20 micrometers.
The first layer can include one or more therapeutic agents. In some embodiments, the first layer can include a polymer. For example, the first layer can be a drug-eluting first layer. In some embodiments, the first layer can include a ceramic (e.g., iridium oxide, titanium oxide, or aluminum oxide). In some embodiments, the medical implant can include a plurality of layers overlying the tie layer.
The medical implant can be a stent. For example, the metallic base can include a plurality of bands and a plurality of connectors extending between adjacent bands and the surface of the metallic base can be at least a portion of an abluminal surface of the bands and connectors.
In another aspect, a medical implant having a metallic base, a tie layer having a rough outer surface, and at least a first layer overlying the rough outer surface of the tie layer is described herein. The tie layer includes magnesium or a magnesium-based alloy. The rough outer surface is defined by pores, projecting grain structures, projecting particles at least partially embedded in the magnesium or the magnesium-based alloy, or a combination thereof. The tie layer has an average thickness of between 1 micrometer and 20 micrometers.
In another aspect, a method of forming a tie layer on a medical implant is described. The method includes applying magnesium or a magnesium-based alloy to at least a portion of a surface of a medical implant and cooling the magnesium or the magnesium-based alloy to produce a tie layer having a rough outer surface. The medical implant includes a metallic composition having a melting temperature greater than melting temperature of the magnesium or the magnesium-based alloy. The magnesium or magnesium-based alloy is applied at a temperature between the melting temperature of the metallic composition of the stent and the melting temperature of the magnesium or the magnesium-based alloy. Applying the magnesium or the magnesium-based alloy at a temperature lower than the melting temperature of the metallic base can permit limited diffusion bonding of the magnesium or the magnesium-based alloy to the metallic base.
In some embodiments, the magnesium or the magnesium-based alloy is cooled at a rate sufficient for producing a microstructure comprising dendritic grains. Dendritic grains form as the magnesium or magnesium-based alloy solidifies on the substrate. Relatively fast cooling that would occur in a thin Mg coating on a relatively thick substrate would produce fine dendrite crystallites. Slower cooling would produce a coarser dendritic grain structure. Coarse dendritic grains can protrude from the tie layer to provide the rough outer surface similar to “orange peel” structure on coarse grain or galvanized steel. In some embodiments, a magnesium-based alloy is applied such that it includes multiple phases. The magnesium-based alloy can be etched after solidification to remove certain phases to leave a plurality of grain structures projecting from the surface of the tie layer. In some embodiments, the magnesium-based alloy can be formed in-situ by first applying a layer of magnesium, followed by applying a second metal. The magnesium and the second metal can then be alloyed by heating the layered structure to a temperature between the melting temperature of the magnesium and the melting temperature of the metallic base.
In other embodiments, the magnesium or the magnesium-based alloy is cooled at a rate sufficient to create shrinkage-induced porosity in the magnesium or the magnesium-based alloy. Shrinkage porosity is formed when the Mg solidifies at a rapid rate such that there is not enough bulk liquid metal in the coating to backfill voids that fill as liquid metal transforms to solid metal with a contraction in volume. This can be accomplished by directing a gas nozzle upon the coating just as it exits from the coating bath. Inert gas, such as argon, can be jetted through a nozzle to cause rapid cooling of the liquid Mg metal laying on the substrate. The gas impingement may also entrap gas molecules in the solidifying metal creating gas porosity in addition to shrinkage porosity. Furthermore, the gas impingement may create turbulence and waves in the liquid metal coating the substrate surface that upon solidification would result in surface contortions that contribute to overall roughness.
In some embodiments, particles are combined with the magnesium or the magnesium-based alloy to produce a matrix of the magnesium or the magnesium-based alloy having particles protruding therefrom to provide the rough outer surface. The particles can have a maximum dimension of between 10 microns and 50 microns.
Various embodiments of the subject matter described herein may provide one or more of the following advantages. In one or more embodiments, a magnesium or magnesium-based alloy containing a tie layer may result in a more secure and robust attachment of a therapeutic layer to a metallic stent. For example, the tie layer may inhibit detachment of large portions of a bioerodible therapeutic layer as it erodes. In some embodiments, a magnesium or magnesium-based alloy tie layer may bioerode to leave behind a bare metal stent. In one or more embodiments, the magnesium or magnesium-based alloy tie layer can be deposited at a temperature below the melting temperature of the metallic stent, which may reduce changes in the material properties of the metallic stent. Moreover, the tie layer may erode, leaving a stable and biocompatible metallic base surface, which can limit unwanted biological reactions.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and also from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 illustrates an exemplary stent.
FIGS. 2A and 2B illustrate exemplary cross-sections of struts of stents.
FIG. 3 illustrates an exemplary method for depositing the tie layer onto struts of a stent.
FIG. 4 is a perspective view of an artificial heart valve in an expanded configuration.
Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
A stent 20 , shown in FIG. 1 , is discussed below as an example of one medical implant according to the instant disclosure. Stent 20 includes a pattern of interconnected struts forming a structure that contacts a body lumen wall to maintain the patency of the body lumen. For example, stent 20 can have the form of a tubular member defined by a plurality of bands 22 and a plurality of connectors 24 extending between and connecting adjacent bands. During use, bands 22 can be expanded from an initial, small diameter to a larger diameter to contact stent 20 against a wall of a vessel, thereby maintaining the patency of the vessel. Connectors 24 can provide stent 20 with flexibility and conformability, permitting the stent to adapt to the contours of the vessel. Other examples of endoprostheses can include covered stents and stent-grafts.
As shown in FIG. 2A , one or more struts of stent 20 include a metallic base 23 and a tie layer 26 . FIG. 2B shows a strut including a metallic base 23 , a tie layer 26 , and a first layer 28 overlying the tie layer. As shown, the tie layer 26 and the first layer 28 can be deposited on one side of the strut. In some embodiments, the stent 20 includes the tie layer 26 on only an abluminal surface of the stent 20 . In other embodiments, the stent 20 can include the tie layer 26 on a luminal surface of the stent 20 . In some embodiments, the stent 20 can include the tie layer 26 on side surfaces of each strut. The stent 20 can also be coated on all sides with tie layer 26 .
The metallic base 23 can form the majority of the stent 20 and may provide the mechanical strength needed to maintain the patency of a lumen upon expansion of stent 20 to expand the lumen during an implantation of the stent 20 . The metallic base 23 can have a variety of dimensions depending upon the particular material used and the intended application for the stent. In some embodiments, the metallic base includes a biostable metal. In some embodiments, the biostable metal can be stainless-steel, platinum-enhanced stainless steel, a cobalt-chromium alloy, a nickel-titanium alloy, a niobium-based alloy, a titanium-based alloy, a tantalum-based alloy, a platinum-based alloy, or some combination thereof. In other embodiments, the metallic base 23 can be a bioerodible metal (e.g., iron or a bioerodible iron alloy). In some embodiments, the metallic base consists essentially of a single metal or single metal alloy. In other embodiments, the metallic base 23 can include multiple metal parts. For example, multiple layers of different metals can be present. In some embodiments, an inner core or outer layer of a radiopaque metal (e.g., gold or platinum) can be present in or over another metal (e.g., stainless steel or Nitinol).
Magnesium is not very solubility in the stent materials discussed above. Interdiffusion, however, will occur regardless of solubility, because atoms from each mating material are free to exchange at elevated temperatures. Elemental concentration gradients can occur within the coating and substrate and across the interface between the two. The zone where there is alloying with limited solubility can be very thin (i.e., less than 1 micron). A zone of limited solubility can have a limited ductility due to the formation of intermetallics. Accordingly, a very thin layer of limited solubility can minimize strains due to the crimping and expansion in a stent, which are distributed throughout the concentration gradients, and thus minimize the risk of failure.
In some embodiments, at least the outer surface of the metallic base 23 has a melting temperature of greater than 650° C. In some embodiments, the metal or metal alloy along the outer surface of the metallic base 23 has a melting temperature of at least 700° C. In still other embodiments, the metal or metal alloy has a melting temperature of at least 800° C. For example, some stainless steels have a melting temperature of about 900° C. By using a metallic base metal or metal alloy having a melting temperature greater than the melting temperature of the tie layer, the tie layer may be bonded to the metallic base 23 with limited diffusion of the tie layer components into the surface of the metallic base. Limited diffusion bonding will not significantly change the material properties of the metallic base 23 . Thus, the metallic base 23 can maintain its mechanical properties.
Tie layer 26 is bonded to at least a portion of the metallic base 23 and has an outer rough surface 27 to accommodate adhesion of first layer 28 . The tie layer 26 includes magnesium or a magnesium-based alloy. As used herein, a magnesium-based alloy is an alloy having more magnesium by weight percentage than any other individual element. In some embodiments, a magnesium-based alloy includes at least 50 weight percent magnesium. In other embodiments, the magnesium-based alloy includes at least 75 weight percent magnesium. The magnesium or magnesium-based alloy is bioerodible. Accordingly, the magnesium degrades within a physiological environment when exposed to body fluids to yield the metallic base 23 as a bare metal stent.
The tie layer can have a thickness of between 1 micrometer and 20 micrometers. The tie layer 26 can be attached to the metallic base 23 via metallurgical bonding between the magnesium of the tie layer 26 and the metal of the metallic base 23 due to a limited diffusion exchange (limited alloying) between the magnesium and the elements of the metallic base 23 along an interface 25 . The limited alloying can be controlled by depositing the magnesium or magnesium-based alloy tie layer onto the metallic base 23 without heating the metallic base 23 above its melting temperature. For example, magnesium has a melting temperature of about 650° C. while stainless steels can have a melting temperature of about 900° C. Moreover, magnesium has a very limited solubility in iron and iron-based alloys. Accordingly, when molten magnesium is applied to iron or an iron-based alloy, a limited but sufficient amount of magnesium diffuses into the iron or iron-based alloy, and a limited amount of iron diffuses into the liquid magnesium to fuse the magnesium to the iron or iron-based alloy. By having limited alloying between the magnesium and the metallic base 23 , the surface properties of the metallic base 23 are not significantly changed. Accordingly, the tie layer 26 may erode and leave the exposed metallic base 23 with a stable and biocompatible surface. A more integral bond between a tie layer and a metallic base could result in a highly pitted and partially corroded surface of a metallic base after the bonded tie layer erodes, which could result in unwanted biological reactions such as an adverse immune response. Accordingly, a tie layer deposited at a temperature below the melting temperature of the metallic base 23 can permit the metallic base 23 to retain its structural and biocompatible properties.
The tie layer can have a cast microstructure including dendritic grains. The metallic base 23 has a wrought microstructure. Dendritic grains are not equiaxed like the grains of a wrought microstructure. Accordingly, the dendritic grains may protrude form the surface of the tie layer to create the roughened surface 27 of the tie layer 26 . In some embodiments, at least 50 percent of the surface of the tie layer comprises dendritic grains. In some embodiments, the tie layer comprises at least 50 percent by volume of dendritic grains. In some embodiments, the grain structure can include a both equiaxed grains and dendritic grains. In some embodiments, the tie layer can include a concentration gradient of grains. For example, may have a greater concentration of dendritic grains along the outer surface to provide the rough outer surface. For example, a thin film of equiaxed grains can form where the magnesium first contacts the wrought substrate containing equiaxed grains. But as the solidification front moves from the first solid film that forms into the remaining molten metal, the grains may adapt a structure from the temperature gradient rather than the nucleation sites on the solid metal and result in the dendrite structure. The grain morphologies can be modified by heating the magnesium bath to different temperatures. At temperatures near the magnesium melting temperature, the liquid metal will very rapidly solidify and have more of an equiaxed structure. If the bath temperature is relatively high (e.g, greater than 750 C), the grains can form as columnar dendritic grains. In other embodiments, essentially all of the magnesium or magnesium-based alloy is in the form of dendritic grains. The dendritic grains may have a length (i.e., a maximum dimension) between 10 micrometers and 50 micrometers.
A cast microstructure can be formed by depositing the magnesium or magnesium-based alloy in a manner that minimizes the cooling rate. A slow cooling rate can be obtained by heating the metallic base 23 prior to or during the process of depositing molten magnesium and/or magnesium-based alloy. The metallic base 23 should be maintained below its melting temperature to limit the amount of diffusion with the magnesium and/or magnesium-based alloy. For example, a stainless steel metallic base 23 may be heated to a temperature of between 500° C. and 800° C. The source of heat can be removed prior to, during, or after the process of depositing the molten magnesium and/or magnesium-based alloy. In some embodiments, the source of heat is removed within 10 seconds of completing the magnesium deposition process. In another embodiment, the stent is fixtured upon a mandrel made of a material with low thermal conductivity, such as a ceramic. The stent substrate thereby cools slowly upon exiting from the coating batch. Other possible methods can include using a superheated coating batch, e.g., magnesium heated to above 750 C.
FIG. 3 depicts an exemplary apparatus for roll coating the tie layer 26 onto the abluminal surface of a metallic base 23 having a plurality of struts. The metallic base 23 is deposited over a roll first layer mandrel 32 . The mandrel 32 is positioned such that an abluminal surface of at least one strut is positioned to contact a bath 34 of the molten magnesium and/or the molten magnesium-based alloy. The first layer process may occur in an inert gas atmosphere, which can keep the molten magnesium from combusting. For example, as shown in FIG. 3 , an argon atmosphere may be used to avoid unwanted reactions between the magnesium and the metal(s) of the metallic base 23 . An optional flow of inert gas 36 may also be used to control the cooling rate of the magnesium or the magnesium-based alloy. The temperature, flow rates, and flow pattern of the inert gas 36 can impact the cooling rate of the magnesium or the magnesium-based alloy. In some embodiments, the inert gas 36 may flow in a direction opposite to the direction of rotation. The mandrel 32 can, in some embodiments, apply heat to the metallic base 23 . In some embodiments, heat may be applied to the stent via a quartz lamp 38 .
The tie layer 26 , in some embodiments, is porous. For example, a shrinkage porosity within the tie layer may be produced by quickly cooling of the tie layer 26 . The cooling rate can be accelerated by having a room temperature or cooled the metallic base 23 and/or by using cooled inert gas during the deposition process. For example, a gas nozzle can be used to impinge argon gas on the coated surface immediately after it emerges from the coating bath. The argon gas can cool the surface by convection thereby increasing the cooling rate. Moreover, gas molecules can become entrapped in the solidifying metal creating gas porosity in addition to shrinkage porosity.
The tie layer 26 can also include particles within a matrix of the magnesium or the magnesium-based alloy. The particles can partially protrude from the surface of the tie layer to provide the roughened surface. Particles having a dimension greater than the thickness of other portions of the magnesium or magnesium-based alloy tie layer 26 can ensure that the particles partially protrude from the surface to create the roughened outer surface 27 . The particles can have a maximum dimension of between 10 microns and 50 microns. The particles can be iron particles, calcium powder, graphite spheres, graphite nanotubes, barium powder, or a combination thereof. In some embodiments, the particles comprise a bioerodible iron or bioerodible iron alloy that may bioerode with the magnesium or the magnesium-based alloy.
A roughened surface on the tie layer may also be produced by using a turbulent flow of inert gas to cool the molten magnesium or magnesium-based alloy. In some embodiments, the cool gas is super cooled. The air flow of cool gas can be directed to create turbulent vortices that may generate waves or other topography in the molten magnesium or molten magnesium-based alloy. This process can be used either alone or in combination with the other processes discussed above. For example, the air flow of cool argon gas 36 of FIG. 3 can be used to create the waves or other topography. Heat can further be applied to the stent during the application of the magnesium and/or magnesium-based alloy to slow the cooling rate of the magnesium and thus increase the time for manipulating the topography of the molten magnesium or magnesium-based alloy before the tie layer solidifies. Heat can be applied in a number of manners. For example, heat may be applied to the stent via the mandrel 32 and/or by using a quartz lamp 38 . Moreover, heating the metallic base 23 can reduce the cooling rate and thus also crease a cast microstructure.
The tie layer 26 , in some embodiments, includes a magnesium-based alloy. In some embodiments, the magnesium-based alloy can include one or more metals having a melting temperature of less than 900° C. For example, zinc (420° C.), aluminum (660° C.), calcium (842° C.), tin (232° C.), and certain rare earth metals have melting temperatures of less than 900° C. Unlike pure metals, alloys melt over a range of temperatures. This melting temperature range can be used to produce the roughened surface of the tie layer. For example, melting a magnesium-based alloy within this range can result in a momentary combination of both liquids and solids as the material cools, thus creating in multiple phases once the tie layer solidifies. Acid etching can be used as well to selectively dissolve one or more phases to create a microscopic roughened surface.
In some embodiments, the magnesium-based alloy can be made in situ after a layer of magnesium is bonded to the metallic base 23 . For example, liquid tin can be applied to a first layer of magnesium at a temperature below the melting point of magnesium. Because tin has a lower melting point than magnesium, the tin can be applied without melting the magnesium. The layered structure could then be heated (e.g., with a quartz lamp 38 ) to a temperature or temperatures of between 200° C. and 650° C. For example, the layered structure could be heated in inert gas at a temperature of between 205-230 C for 1 hour. Initially there will be some solid state diffusion between the tin and magnesium. Then when there is sufficient tin in the magnesium, a eutectic reaction may occur between the tin and magnesium wherein the tin will melt, diffuse, and form a diffusion bond with the magnesium to form an alloy of magnesium and tin without having the tin and magnesium significantly alloy with the metallic base 23 . The in situ formation of the magnesium-based alloy can result in a concentration gradient of different elements within the magnesium-based alloy of the tie layer. Once the alloy is formed, the cooling rate can be controlled to form the rough outer surface (e.g., to create dendritic grains or to create shrinkage-induced porosity).
The first layer 28 overlying the tie layer 26 can include a polymer, a ceramic, a metal, an organic substance, and/or a therapeutic agent. For example, ceramics such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, and iridium oxide can provide a pro-healing surface. The tie layer 26 can promote the adhesion of a preheating surface to the stent 20 . In some embodiments, the stent 20 includes multiple layers deposited over the tie layer 26 .
In some embodiments, the first layer 28 includes one or more therapeutic agents. The therapeutic agent can be alone, in a polymer matrix, in a organic matrix, or in a ceramic matrix. The therapeutic agent may be any pharmaceutically acceptable agent (such as a drug), a biomolecule, a small molecule, or cells. Exemplary drugs include anti-proliferative agents such as paclitaxel, sirolimus (rapamycin), tacrolimus, everolimus, biolimus, and zotarolimus. Exemplary bio-molecules include peptides, polypeptides and proteins; antibodies; oligonucleotides; nucleic acids such as double or single stranded DNA (including naked and cDNA), RNA, antisense nucleic acids such as antisense DNA and RNA, small interfering RNA (siRNA), and ribozymes; genes; carbohydrates; angiogenic factors including growth factors; cell cycle inhibitors; and anti-restenosis agents. Exemplary small molecules include hormones, nucleotides, amino acids, sugars, and lipids and compounds have a molecular weight of less than 100 kD. Exemplary cells include stem cells, progenitor cells, endothelial cells, adult cardiomyocytes, and smooth muscle cells.
Certain therapeutic agents can react with the magnesium or the magnesium-based alloy to accelerate the erosion of the tie layer and/or degrade the therapeutic agent. Accordingly, the therapeutic agent can be segregated from the tie layer. In some embodiments, the therapeutic agent is segregated from the tie layer with an essentially non-porous and conformal coating of a polymer, a ceramic, or an organic substance, whereby the therapeutic agent can be deposited over the non-porous and conformal coating. In some embodiments, the non-porous and conformal coating can include titanium oxide, aluminum oxide, zinc oxide, silicon oxide, and/or iridium oxide. A barrier layer disposed over the therapeutic agent can also be used for controlling the release of the therapeutic agent. The barrier layer can be a porous, inorganic layer deposited by atomic layer deposition. When the barrier layer is deposited over the therapeutic agent, the deposition temperature may be selected to avoid or reduce heat degradation of the therapeutic agent. For example, a deposition temperature of less than 125° C. may be useful for preserving the therapeutic agent during the deposition process. Deposition temperatures as low as 50° C. may be used for barrier layers such as aluminum oxide.
Stent 20 can be of a desired shape and size (e.g., coronary stents, aortic stents, peripheral vascular stents, gastrointestinal stents, urology stents, tracheal/bronchial stents, and neurology stents). Depending on the application, the stent can have a diameter of between, e.g., about 1 mm to about 46 mm. In certain embodiments, a coronary stent can have an expanded diameter of about 2 mm to about 6 mm. In some embodiments, a peripheral stent can have an expanded diameter of about 4 mm to about 24 mm. In certain embodiments, a gastrointestinal and/or urology stent can have an expanded diameter of about 6 mm to about 30 mm. In some embodiments, a neurology stent can have an expanded diameter of about 1 mm to about 12 mm. An abdominal aortic aneurysm (AAA) stent and a thoracic aortic aneurysm (TAA) stent can have a diameter of about 20 mm to about 46 mm. The stent can be balloon-expandable, self-expandable, or a combination of both (e.g., see U.S. Pat. No. 6,290,721).
Stent 20 can also be part of a covered stent, a stent-graft and/or other endoprostheses.
The endoprosthesis, in some embodiments, can be an artificial heart valve. For example, an artificial heart valve 50 is depicted in FIG. 4 . The heart valve 50 has a generally circular shape. A stent member 52 is formed of a wire including a metallic base, a tie layer, and optionally a first layer. The stent member 52 is formed in a closed, zig-zag configuration. In other embodiments, the stent member of the artificial heart valve can include a plurality of bands with connectors in between. The valve member 55 is flexible and includes a plurality of leaflets 56 . The leaflet portion of the valve member 55 extends across or transverse of the cylindrical stent member 52 . The leaflets 56 are the actual valve and allow for one-way flow of blood. Extending from the periphery of the leaflet portion is a cuff portion 57 . The cuff portion is attached to the stent by sutures 58 . Sutures 53 can be used to attach the artificial heart valve 50 to heart tissue. The valve member 55 can be formed of polymer such as polytetrafluoroethylene or a polyester. In other embodiments, the valve member 55 can be a bioerodible polymer. In some embodiments, the valve member 55 can be adhered to the tie layer direct.
The tie layer 26 may also be applied to metallic bases of other types of medical implants. For example, orthopedic implants, bioscaffolding, bone screws, and aneurysm coils may all have one or more of the tie layers described herein.
All publications, patent applications, patents, and other references mentioned herein are incorporated by reference herein in their entirety.
A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of this disclosure. Accordingly, other embodiments are within the scope of the following claims.
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A medical implant includes a metallic base, a tie layer, and at least a first layer overlying an outer surface of the tie layer. The tie layer is bonded to at least a portion of a surface of the metallic base. The tie layer includes magnesium or a magnesium-based alloy. The tie layer can have an outer surface comprising dendritic grains. The tie layer can have a rough outer surface defined by pores, projecting grain structures, and/or projecting particles. A method of producing a tie layer on a medical device includes applying magnesium or a magnesium-based alloy to the medical device and cooling the magnesium or the magnesium-based alloy to produce a rough outer surface.
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FIELD OF THE INVENTION
This invention generally relates to ultrasound imaging of the human anatomy for the purpose of medical diagnosis. In particular, the invention relates to a method for imaging the human anatomy by detecting the intensity of ultrasonic echoes reflected by a scanned volume in a human body.
BACKGROUND OF THE INVENTION
Conventional ultrasound scanners create two-dimensional B-mode images of tissue in which the brightness of a pixel is based on the intensity of the echo return. The basic signal processing chain in the conventional B mode is depicted in FIG. 1. An ultrasound transducer array 2 is activated to transmit an acoustic burst along a scan line. The return RF signals are detected by the transducer elements and then formed into a receive beam by the beamformer 4. The beamformer output data (I/Q or RF) for each scan line is passed through a B-mode processing chain 6 which includes an equalization filtering, envelope detection and logarithmic compression. Depending on the scan geometry, up to a few hundred vectors may be used to form a single acoustic image frame. To smooth the temporal transition from one acoustic frame to the next, some acoustic frame averaging 8 may be performed before scan conversion. The frame averaging may be implemented by a FIR or an IIR filter. In general, the compressed images are in R-θ format (for a sector scan) which is converted by the scan converter 10 into X-Y format for video display. On some systems, frame averaging may be performed on the video X-Y data (indicated by dashed block 12) rather than the acoustic frames before scan conversion, and sometimes duplicate video frames may be inserted between acoustic frames in order to achieve a given video display frame rate (typically 30 Hz). The video frames are passed on to a video processor 14, which basically maps the video data to a display gray map for video display.
System control is centered in a host computer 20, which accepts operator inputs through an operator interface 22 (e.g., a keyboard) and in turn controls the various subsystems. (In FIG. 1, only the image data transfer paths are depicted.) During B-mode imaging, a long sequence of the most recent images are stored and continuously updated automatically in a cine memory 16. Some systems are designed to save the R-θ acoustic images (this data path is indicated by the dashed line in FIG. 1), while other systems store the X-Y video images. The image loop stored in cine memory 16 can be reviewed via track-ball control, and a section of the image loop can be selected for hard disk storage. For an ultrasound scanner with free-hand three-dimensional imaging capability, the selected image sequence stored in cine memory 16 is transferred to the host computer 20 for three-dimensional reconstruction. The result is written back into another portion of the cine memory, from where it is sent to the display system 18 via video processor 14.
Referring to FIG. 2, the scan converter 10 comprises an acoustic line memory 24 and an X-Y memory 26. The B-mode data stored in polar coordinate (R-θ) sector format in acoustic line memory 24 is transformed to appropriately scaled Cartesian coordinate intensity data, which is stored in X-Y memory 26. A multiplicity of successive frames of B-mode data are stored in cine memory 16 on a first-in, first-out basis. The cine memory is like a circular image buffer that runs in the background, continually capturing image data that is displayed in real time to the user. When the user freezes the system, the user has the capability to view image data previously captured in cine memory.
The host computer 20 comprises a central processing unit (CPU) 28 and a random access memory 30. The CPU 28 has read only memory incorporated therein for storing routines used in transforming an acquired volume of intensity data into a multiplicity of three-dimensional projection images taken at different angles. The CPU 28 controls the X-Y memory 26 and the cine memory 16 via the system control bus 32. In particular, the CPU 28 controls the flow of data from the acoustic line memory 24 or from the X-Y memory 26 of the scan converter 10 to the video processor 14 and to the cine memory 16, and from the cine memory to the video processor 14 and to the CPU 28 itself. Each frame of imaging data, representing one of a multiplicity of scans or slices through the object being examined, is stored sequentially in the acoustic line memory 24, in the X-Y memory 26 and in the video processor 14. IN parallel, image frames from either the acoustic line memory or the X-Y memory are stored in cine memory 16. A stack of frames, representing the scanned object volume, is stored in section 16A of cine memory 16.
Two-dimensional ultrasound images are often hard to interpret due to the inability of the observer to visualize the two-dimensional representation of the anatomy being scanned. However, if the ultrasound probe is swept over an area of interest and two-dimensional images are accumulated to form a three-dimensional volume, the anatomy becomes much easier to visualize for both the trained and untrained observer.
In order to generate three-dimensional images, the CPU 28 can perform a series of transformations using a ray casting algorithm such as the one disclosed in U.S. Pat. Nos. 5,226,113 or 5,485,842. The ray-casting technique is applied to the data for the source data volume of interest retrieved from section 16A of cine memory 16. The successive transformations may involve a variety of projection techniques such as maximum, minimum, composite, surface or averaged projections made at angular increments, e.g., at 10° intervals, within a range of angles, e.g., +90° to -90°. Each pixel in the projected image includes the transformed data derived by projection onto a given image plane. In addition, at the time when the cine memory was frozen by the operator, the CPU 28 optionally stores the last frame from the X-Y memory 28 at multiple successive addresses in section 16B of cine memory 16. The projected image data for the first projected view angle is written into the first address in cine memory section 16B, so that the projected image data in a region of interest is superimposed on the background frame. This process is repeated for each angular increment until all projected images are stored in cine memory section 16B, each projected image frame consisting of a region of interest containing transformed intensity data and optionally a background perimeter surrounding the region of interest consisting of background intensity data not overwritten by the transformed intensity data. The background image makes it clearer where each displayed projection is being viewed from. The operator can then select any one of the projected images for display. In addition, the sequence of projected images can be replayed on the display monitor to depict the object volume as if it were rotating in front of the viewer.
Various types of multi-row transducer arrays, including so-called "1.25D" and "1.5D" arrays, have been developed to improve upon the limited elevation performance of present single-row ("1") arrays. As used herein, these terms have the following meanings: 1D) elevation aperture is fixed and focus is at a fixed range; 1.25D) elevation aperture is variable, but focusing remains static; and 1.5D) elevation aperture, shading, and focusing are dynamically variable, but symmetric about the centerline of the array.
In free-hand three-dimensional ultrasound scans, a transducer array (1D to 1.5D) is translated in the elevation direction to acquire a substantially parallel set of image planes through the anatomy of interest. These images can be stored in the cine memory and later retrieved by the system computer for three-dimensional reconstruction. If the spacings between image frames are known, then the three-dimensional volume can be reconstructed with the correct aspect ratio between the out-of-plane and scan plane dimensions. If, however, the estimates of the interslice spacing are poor, significant geometric distortion of the three-dimensional object can result.
In the prior art, a variety of motion control and position-sensing methods have been proposed to control or track the elevational motion of the probe respectively. However, these systems are often costly and cumbersome to use in a clinical environment. Therefore, to reconstruct a three-dimensional image with good resolution in the elevation direction, it is highly desirable to be able to estimate the scan plane displacements directly from the degree of speckle decorrelation between successive image frames.
In International Patent WO 97/00482, Fowlkes et al. proposed a scan plane motion tracking method which is based on computing the correlation between image frames. It was stated that their correlation method is an adaptation of the decorrelation techniques used for monitoring blood flow. A review of such prior art indicates that there are two general approaches as follows:
(1) Trahey et al., in "Speckle pattern correlation with lateral aperture translation: experimental results and implications for spatial compounding," IEEE Trans. Ultrasonics, Ferroelec. and Freq. Control, Vol. UFFC-33 (1986), pp. 257-264, reported the first study that used a full correlation function of intensities in ultrasound images. This approach uses RF or detected image data prior to compression, which is evident from the fact that the correlation function is normalized by the total echo intensities (i.e., is system gain dependent). Chen et al., in "Determination of scan-plane motion using speckle decorrelation: theoretical considerations and initial test," Int. J. Imaging Syst. Technol., Vol. 8 (1997), pp. 38-44, reported phantom studies using this correlation method for three-dimensional sweep distance estimation.
(2) Bohs et al., in "A novel method for angle independent ultrasonic imaging of blood flow and tissue motion," IEEE Trans. Biomed. Eng., Vol. 38 (1991), pp. 280-286, proposed a simpler correlation method which should work with compressed ultrasound images. This is referred to as the SAD method since it is based on computing the sum of absolute differences between corresponding pixels in two kernels being correlated. This computationally efficient method was found to perform almost as well as the full correlation function of Trahey et al. Shehada et al., in "Ultrasound methods for investigating the non-Newtonian characteristics of whole blood," IEEE Trans. Ultrasonics, Ferroelec. and Freq. Control, Vol. UFFC-41 (1994), pp. 96-104, also reported a flow measurement study based on SAD correlation of ultrasound images. For flow measurement, the SAD method basically consists of finding the displacement vector within the scan plane that minimizes the SAD, so only relative changes in SAD are pertinent. In general, however, for a given kernel size the SAD can vary significantly with dynamic range setting and post-processing filtering.
On ultrasound scanners with three-dimensional free-hand scan capability, the images stored in cine memory typically have already gone through a logarithmic or some other highly nonlinear compression for display (typically an 8-bit amplitude display). These images may have also gone through some post-processing filters such as for smoothing or edge enhancement. The compression and filtering operations are often not reversible, and any attempt to make even an approximate "decompression" may introduce quantization noise in the images. For this reason, the first approach discussed above, which is designed for pre-compressed images, may not be most suitable for sweep speed estimation.
The SAD approach works with compressed images and has the advantage of computational speed. However, for three-dimensional reconstruction we need to quantify the actual decorrelation from frame to frame in order to estimate the sweep distance. Using SAD alone would require calibration for all possible combinations of display dynamic range (which may be depth dependent), filters, kernel size and kernel depth position.
Thus, there is a need for a new correlation index that adapts to different dynamic range settings and post-processing filters.
SUMMARY OF THE INVENTION
The present invention is a method and an apparatus for tracking scan plane motion in free-hand three-dimensional ultrasound scanning using adaptive speckle correlation. The method employs a correlation index which adapts to different display dynamic range and post-processing filters. The apparatus in accordance with one preferred embodiment comprises: means for choosing a kernel within each image frame for correlation calculations; means for rejecting duplicate image frames; means for measuring the degree of correlation between successive image frames; means for rejecting correlation estimates which may be associated with hand jitter and other artifacts; and means for computing the average frame-to-frame (i.e., interslice) spacing based on the average correlation estimate. These means are incorporated into a host computer which interfaces with the cine memory. A major benefit of this image-based motion tracking technique is that it enables three-dimensional reconstruction with good geometric fidelity, without use of any external position-sensing device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing the major functional subsystems within a real-time ultrasound imaging system.
FIG. 2 is a block diagram showing means for reconstructing frames comprising successive volumetric projections of pixel intensity data.
FIG. 3 is a schematic showing a typical region-of-interest box within one image frame and further showing a selected kernel within the region of interest.
FIG. 4 is a flowchart showing the steps of the method in accordance with the preferred embodiment by which the average frame-to-frame spacing d is estimated for use in three-dimensional reconstruction.
FIG. 5A is a graph showing the probability density distribution f y (y) of the log-compressed noise spectral power y for m=100, where m=E[x] is the expected value of x.
FIG. 5B is a graph showing the probability density distribution f y (SAD=|y 1 -y 2 |), where y 1 and y 2 are independent identically distributed random variables that represent the amplitude of corresponding pixels in two kernels being correlated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 shows a typical region-of-interest (ROI) box 34 within one image frame 36 (a sector scan in this example) as selected by the user. Assume that N frames generated by a free-hand scan are stored in cine memory. The process of estimating the average frame-to-frame spacing d for three-dimensional reconstruction (which is performed by the host computer based on the data retrieved from cine memory) is described in FIG. 4. First, a kernel 38 (M×M pixels in this example, but in general the kernel does not have to be square) within the ROI 34 that shows a relatively pure speckle pattern (no macroscopic structures) must be identified (step 40) since the correlation method in the present invention is based on the statistics of pure speckle arising from a diffuse scattering medium. The kernel 38 can be selected manually (e.g., by means of a trackball) based on visual judgment of one or more image frames. Alternatively, some automated method can be used to search for a kernel whose pixel amplitude histogram is consistent with the theoretical speckle distribution. For example, such tests can be based on a measure of the histogram width relative to normal dynamic range settings. Kernels whose mean pixel values are too low (no signal) or whose variances are too large (not homogeneous) should be rejected. As shown in FIG. 3, a good initial kernel 38 to test is one at any of the four corners of the ROI 34--assuming the user tends to position the structures of interest in the center of the ROI.
Before proceeding to compute the correlation between kernels in successive image frames, any duplicate image frames present in the N source frames are identified and rejected (step 42 in FIG. 4). Duplicate frames are sometimes inserted in between acoustic image frames in order to match the video monitor display rate (typically 30 Hz). If the duplicate frame pairs are exactly identical, they can be easily detected based on the criterion that the SAD be substantially equal to zero. If the duplicate frames are not exactly identical, due, for example, to frame averaging effects, then some thresholding method may be used to detect the nearly identical frames. For example, if more than some percentage (say 25%) of the pixels in the kernel of a new image frame differ from those in the previous frame by more than some value, then the new image frame passes as a new acoustic frame; otherwise it is considered as a duplicate image frame which is to be rejected. Alternatively, for improved reliability in screening out duplicate frames, it may be necessary to consider the ensemble statistics of SAD values for all (N-1) source frame pairs, and to discard the frames having SAD values that lie outside normal statistical deviations.
Having screened out possible duplicate frames, the next step (step 44 in FIG. 4) is to compute a correlation index (CI) for all adjacent frame pairs in the remaining set of acoustic frames. In the invention, a correlation index is used which can be considered as a normalized SAD that can adapt to different kernel sizes, display dynamic ranges and post-processing filters. This index is advantageous because it is much more computationally efficient than the full correlation function disclosed by Chen et al., which requires image decompression and may use up to 10 frames for each correlation function estimate. The correlation index of the invention ranges from 100% for identical kernels to zero for completely independent speckle patterns. In principle, the correlation index may also become negative if the two kernels pick up different structures.
In general, there is no guarantee that the kernel chosen based on one frame will also contain a homogeneous speckle pattern in other frames. Hence, a screening test (step 46 in FIG. 4) of the correlation index estimates is in order. For example, we may choose to discard all correlation index samples below a certain reliability threshold (e.g., 20%) that are indicative of axial and/or lateral scan-plane jitter, a skid in the elevation motion, or frame averaging (which can make uncorrelated frames look weakly correlated). It may also be useful to count the remaining good correlation index values (step 47 in FIG. 4) to see if they constitute a significant fraction of the N frames (e.g., "at least 10% of the correlation index values must be good"). If too few frames are reliable (CI>20%), then the user should be prompted (step 48) to either re-scan at a slower and more steady speed, or to manually enter an estimate of the total sweep distance.
If there are enough good correlation index samples, their average should be taken (step 50 in FIG. 4) to reduce statistical variability. The result can be used to compute the corresponding average interslice spacing d (step 52), based on a pre-calibrated CI versus d model (stored in memory in the CPU 28 shown in FIG. 2) for each probe type and kernel depth. If there are enough good correlation index samples, the corresponding average d should be quite reliable for three-dimensional reconstruction.
At the heart of the invention is an adaptive method for normalizing the SAD of two image kernels such that the resultant correlation index is independent of display dynamic range, post-processing filter and kernel size to within reasonable limits. The key idea is to determine from theoretical speckle statistics what the average SAD per pixel would approach if the image kernels were so far apart that they become statistically independent (if there is no frame averaging).
It is well known that the detected speckle amplitude for a diffuse homogeneous scattering medium is described by a Rayleigh distribution. Suppose the image compression prior to display can be modeled by a simple logarithmic function as follows:
y=10 log[x+1] (1)
Standard statistical operations indicate that if x is Rayleigh distributed, then the probability density function (pdf) of y is ##EQU1## where a=(0.1)ln(10) is a constant, and m=E[x] is the expected value of x which is dependent on system gain. For an 8-bit linear gray map, y is mapped to [0, 255] for display and a sample histogram for m=100 is plotted in FIG. 5A.
Suppose y 1 and y 2 are independent identically distributed random variables that represent the amplitude of corresponding pixels in the two kernels being correlated. We need to determine the pdf of SAD=|y 1 -y 2 |. First, the pdf of (-y 2 ) is simply the mirror image of that of y 2 , which is assumed to be the same as that of y 1 . The pdf of y 1 +(-y 2 ) is given by the convolution of their respective pdfs, which is shown in FIG. 5B. Since the pdf of the sum is a symmetric function about zero, the pdf of its absolute value (SAD) is simply the positive half of the distribution (times two).
Note that the half-maximum width w of the pdf of (y 1 -y 2 ) (FIG. 5B) is about 1.5 times that of an individual y (FIG. 5A). In practice, the compression function may be different from Eq. (1), but one can always follow the same approach to derive the pdf of SAD. If the compression function does not deviate greatly from Eq. (1) and the post-processing spatial filtering effects are mild, the width of the SAD histogram can be approximated by a constant γ times that of each image kernel, where γ≅1.5. If the spatial filters are very strong, then the value of γ may have to be adjusted accordingly. To those skilled in the art it is clear that the width of the pixel amplitude distribution over an (M×M) pixel kernel in the k-th image frame can also be defined by its rms pixel value, or in accordance with the preferred embodiment, by simply the average absolute deviation as follows: ##EQU2## in which y k (i) is amplitude of the i-th pixel, and mean k is the mean amplitude over all M 2 pixels. In general, Sk is a function of dynamic range setting and post-processing spatial filters.
Suppose the SAD k image has been computed for two corresponding kernels in the k-th and (k+1)-th frames as follows: ##EQU3## As the frame separation increases, the average absolute difference per pixel, i.e., SAD k /M 2 , will increase from zero to a limiting value of (γs k ) as the two kernels become statistically independent. Hence, a suitable correlation index can be defined as follows: ##EQU4## in which γ≅1.5 for a log-compressed speckle image.
Experiments performed using different types of imaging arrays indicated that the correlation index can be described very well by an exponential decay function in interslice spacing d as follows:
CI=exp(-d/D.sub.z) (6)
where D z is the decorrelation length which is a characteristic of the elevational beam profile of the probe. Since the elevational beam profile varies with depth due to diffraction and tissue attenuation effects, D z is generally a function of depth z for a given transmit frequency. Since the beam profile is generally less coherent and complex in the near field, D z is expected to be smaller in the near field than in the mid and far fields.
Given a correlation index estimate, the corresponding interslice spacing can be computed as follows:
d=-D.sub.z ln(CI) (7)
The fact that CI decays exponentially with d may prove to be an advantage for three-dimensional scanning: CI is very sensitive to small displacements or slow motion. As d increases beyond the elevational slice thickness, CI tapers off slowly towards zero. From Eq. (7), for CI<20%, a small variation in CI can translate into a large change in d. Hence, a reasonable reliability threshold (step 46 in FIG. 4) for rejecting bad correlation index samples is CI=20%, for example; that is, any value below the threshold may be caused by hand jitter or skidding of the probe. Equation (7) can be used to compute the average interslice spacing for the N frames based on the average value of all correlation index values greater than the reliability threshold.
Rather than use a processor to compute the average interslice spacing d during scanning, the relationship between d and CI can be specified by other means, such as a look-up table. However, the exponential model of Eq. (6) offers the convenience that at each depth, the relationship is completely specified by a decorrelation length. For a given probe, the decorrelation lengths for different depths or z-intervals can be calibrated by performing a controlled experiment wherein a motor-driven probe-holder is used to translate the probe at constant speed over a homogeneous scattering phantom.
In the derivation of CI, no frame averaging was assumed. In practice, frame averaging tends to produce additional correlation between adjacent acoustic frames no matter how far apart they are spaced. This means that frame averaging will cause the correlation index to decay more slowly with increasing d (larger effective D z ) and towards some non-zero baseline level depending on the degree of frame averaging. This has been confirmed in experimental studies which showed that the exponential decay model of Eq. (6) still holds as long as a larger effective D z is used and the reliability threshold for the correlation index is chosen above the non-zero baseline correlation associated with frame averaging effects.
The foregoing preferred embodiments have been disclosed for the purpose of illustration. Variations and modifications of the basic concept of the invention will be readily apparent to persons skilled in the art. In particular, it will be appreciated that the invention can be used to compute a spacing between adjacent scan planes which is not an average value. All such variations and modifications are intended to be encompassed by the claims set forth hereinafter.
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A method and an apparatus for tracking scan plane motion in free-hand three-dimensional ultrasound scanning using adaptive speckle correlation. The method employs a correlation index which adapts to different display dynamic range and post-processing filters. The method may include the following steps: choosing a kernel within each frame image for correlation calculations; rejecting duplicate image frames; measuring the degree of correlation between successive image frames; rejecting correlation estimates which may be associated with hand jitter and other artifacts; and computing the average frame-to-frame (i.e., interslice) spacing based on the average correlation estimate. This image-based motion tracking technique enables three-dimensional reconstruction with good geometric fidelity, without use of any external position-sensing device.
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RELATED APPLICATIONS
[0001] This application claims the benefit of priority to U.S. Provisional application No. 60/904,602, filed on Mar. 1, 2007 and entitled HAY BALE FLAKE-SEPARATING AND FLAKE-DISPENSING DEVICE, SYSTEM AND METHOD, the contents of which are hereby incorporated herein in their entirety by this reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of baled hay as livestock feed. More particularly, it concerns handling so-called square-baled hay to controllably distribute high-nutrient flakes as needed in a pasture for feeding livestock such as livestock.
BACKGROUND OF THE INVENTION
[0003] Conventionally, loaves or bales of hay (formed from “windrows” after the hay is cut) are dispersed by hand and shovel or pitchfork over a pasture as needed. The use even of a pitchfork incidentally damages the individual hay leaves/stems, often inadvertently knocking from the stem the hay's leaves, which contain most of the hay's protein and other nutrients, thereby reducing the nutritional content of the hay for livestock feed purposes. Semi-automatic or automatic means of dispersing hay for feed from un-strung bales for feed purposes heretofore have included devices that effectively pulverize the hay, which makes dispersing thereof quite simple but equally ineffective, since the nutritional value of the hay's leaves is greatly reduced by threshing or pulverizing the hay in the bale. Moreover, dispersing of hay for use as livestock feed conventionally is barely controlled if at all, since both the manual and the semi-automatic means described above rely on manual spreading and/or uncontrolled dispersing, both of which leave too little hay where livestock might be feeding or too much hay where livestock might not be feeding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIGS. 1A and 1B respectively are a top plan view and a side elevation illustrating the invention in accordance with one embodiment in which a flaker device is mounted for flake separating and dispensing from one or more bales of hay loaded on a stack mover towed by a vehicle.
[0005] FIG. 2 is a rear elevation of the flaker device of FIGS. 1A and 1B , in accordance with one embodiment of the invention.
[0006] FIG. 3 is a cutaway top plan view of the flaker device corresponding to FIG. 2 .
[0007] FIGS. 4A and 4B respectively illustrate one of the two opposing flaker wheels of FIGS. 2 and 3 , in a front elevation and a top plan view.
[0008] FIGS. 5A and 5B respectively are a bottom view and side elevation of the flaker device drive mechanism that form a part of the invention shown in FIGS. 1A and 1B .
[0009] FIGS. 6A , 6 B and 6 C respectively are a rear elevation, a side elevation and a top plan view of the pusher board that forms a part of the flaker device drive mechanism shown in FIGS. 5A and 5B .
[0010] FIGS. 7A and 7B respectively are a front and side elevation of the pusher block that forms a part of the flaker device drive mechanism shown in FIGS. 5A and 5B .
[0011] FIGS. 8A , 8 B and 8 C respectively are a front elevation, a side elevation and a top plan view of the fore board shown in FIG. 3 .
[0012] FIGS. 9A , 9 B and 9 C respectively are a side elevation, a front elevation and a top plan view of the flaker wheel frame of FIGS. 1A and 1B , with Details A and B illustrating sections taken along the lines A-A and B-B respectively of FIG. 9A .
[0013] FIGS. 10A , 10 B and 10 C respectively are a front elevation, a left side elevation and a top plan view of the bed of the flaker device shown in FIGS. 1A and 1B .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] The invention in accordance with a preferred embodiment involves a device, system and method for the controlled separating and dispensing of discrete flakes from a bale of hay in a pasture or enclosure to feed livestock such as livestock. The flakes are separated and dispensed by dropping in accordance with one embodiment of the invention by simple mechanical controls within the cab of a truck that mounts the device. The flakes are singularly and discretely dispensed by sequentially dropping them substantially intact so that their nutritional value is substantially undiminished. The flakes are dispensed wherever and whenever they are needed by simply driving around and pushing a lever that activates the bale conveyor and flaking device.
[0015] The flaking device in accordance with one embodiment of the invention features opposing flake wheels aligned with either side of the bale of hay, the flake wheels rotating freely as the bale is advanced therebetween along a drive mechanism (in what will be referred to herein as a passive flake-separating and flake-dispensing mechanism), the flake wheels each including a roller with a upper an lower pluralities of arcuately spaced blades aligned and dimensioned partly to penetrate and slightly to pressure or compress the bale of hay thus to separate a flake from an outward end thereof. Only the drive mechanism on which the bale of hay rests is driven, as by a hydraulic motor/chain/sprocket/push plate power mechanism that is easily turned on and off as needed or desired by a vehicle operator (other moving parts of the flaker device being passive or idle).
[0016] The accompanying drawings and the components depicted therein are referred to orientationally herein consistently with the direction of travel of the vehicle towing the invented flaker device. For example, it will be appreciated that front, left, right, and rear are relative to the forward, left, right and rearward of the directionally oriented vehicle, e.g. the tractor, shown in FIGS. 1A and 1B .
[0017] FIGS. 1A and 1B illustrate the invented bale flaker device 10 coupled with a stack mover (or so-called “stack wagon”), the two being towed behind a vehicle such as a tractor. Those of skill in the art will appreciate that a square-baled hay can weight as much as 1800 pounds or more, depending upon density and moisture content. Those of skill also will appreciate that square-baled hay is alternatively dimensioned to be approximately 3′×3′×6′, 4′×4′×6′ or 4′×4′×8′. These are formidable sizes and weights, and thus robust drive mechanisms are required to transport them. Thus, plural bales of hay positioned on a stack mover as shown are transported by any suitable conveyance (e.g. a hydraulic motor-drive chain-and-sprocket system) toward the invented flaker device 10 . In order to hold them together to maintain their individual integrity, it will be understood that the bales of hay are tied or stringed while stacked or advanced along the conveyance.
[0018] As bales of hay are advanced, a forward one thereof is advanced onto a bed 12 of flaker device 10 . The driver of the tow vehicle aligns the bale on bed 12 against a fore board 14 , and cuts the ties or strings. When the driver pushes a lever on the tow vehicle, a motor-chain-sprocket drive system or other suitable conveyance 16 including a push plate 18 advances the loose bale of hay laterally along bed 12 . Flaker device 10 will be understood to exert slight pressure thus to compress the bale of hay thereon, as it is conveyed between opposing, counter-rotating, idle flaker wheels 20 and 22 . Opposing flaker wheels 20 and 22 include freely rotating rollers 23 and 24 positioned on vertically oriented opposing spindles 25 and 26 , with plural, arcuate blades such as blades 28 , 30 , 32 and 34 mounted on the rollers. Those of skill in the art will appreciate that the plural blades smoothly “knife” into the edge of the hay bale advancing there past and compress and penetrate a terminal region of the hay to separate a so-called flake, as illustrated.
[0019] The arcuate spacing of the blades and their depth of penetration are dimensioned such that they separate flakes approximately 4-6″ thick. When the flake is separated and begins to fall from flaker device 10 toward the ground, the driver of the tow vehicle pulls the lever to stop the conveyance of the bale along bed 12 . Those of skill in the art will appreciate that hay bales have a propensity for separation along any one of a near infinity of plural planes orthogonal to their long axis, which propensity is capitalized on by the current invention to produce uniformly sized and shaped, substantially intact flakes that exhibit high nutritional value because of their semi-automatic dispensing from flaker device 10 .
[0020] It will be understood from an operational standpoint, after dispensing an entire bale, the driver of the tow vehicle returns the flaker device's conveyance to its initial position to accommodate another bale of hay, pushes a second, stack mover handle or lever (not shown) to load the next bale on the flaker device bed, leaves the tow vehicle's engine idling w/the steering wheel turned slightly, gets off the tow vehicle, unstrings or unties the bale that just landed on the flaker device bed and aligns it with fore board 14 , returns to the tow vehicle, drives to the next flake drop destination, and again pushes the first flaker device lever (not shown) to separate and dispense the next flake where needed.
[0021] FIG. 2 illustrates operation of invented flaker device 10 from a forward-looking perspective, with flakes separated and dispensed therefrom to the right. The drawing is believed to be self-explanatory from the above discussion.
[0022] FIG. 3 illustrates operation of invented flaker device 10 from a downward-looking perspective, with flakes separated and dispensed therefrom also to the right. The drawing is believed to be self-explanatory from the above discussion.
[0023] FIGS. 4A and 4B illustrate one of two identical flaker wheels 20 and 22 that form flakes in operation within invented flaker device 10 . Those of skill in the art will appreciate that wheels 20 and 22 are identically formed but when mounted on their spindles within the frame of the flaker device counter-rotate relative to one another. Those of skill also will appreciate that plural blades 28 , 30 (which are typical but which represent only two of the sixteen blades provided on each of two flaker wheels 20 and 22 , as illustrated) are formed of ⅝″ thick hot-rolled steel in a generally isosceles triangular shape the right-angled vertex of which extend outwardly from the roller, in accordance with one embodiment of the invention. In another embodiment of the invention, each of the plural blades is formed as a 70° interior angle-bent length of round ⅝″ diameter shaft with the ends sheared and welded to the wheels as described. (Such an alternative embodiment leaves a triangular opening in each blade that lowers the overall weight of the invented device and permits the hay's leaves and stems to intrude somewhat therein, through and around while an intact flake is being separated.) Each blade is dimensioned approximately as illustrated to have an approximately 5¾″ depth and an approximately 11-12″ height where attached, as by welding, to the roller. The blades are arranged in plural vertically aligned pairs each of which there are eight substantially evenly spaced arcuately around the roller's circumference.
[0024] Those of skill in the art will appreciate by brief reference to FIG. 2A that the number, placement, dimension, and arcuate spacing of the blades are such that the center one of the three inwardly oriented blades during the flaking operation penetrate the bale of hay on the bed of the flaker device by only approximately 2-3″, while all three blades effectively compress and control a terminal end of the bale of hay. This structure and configuration has been discovered to be sufficient for slight compression and cutting separation of a flake but not sufficient for the trailing blade to interfere with the forward travel of the bale of hay. The flake is cleanly separated and gently released by the counter-rotation of the flaker wheels mounting the arcuately spaced and opposing, aligned pairs of upper and lower vertically aligned blades.
[0025] Thus, those of skill will appreciate that the invention may be characterized as combining a single non-driven (idle) pair of opposing laterally positioned rollers with a powered drive or transfer mechanism, wherein the roller pair and the blades mounted thereon neither pull nor push bale along its longitudinal axis, instead simply impacting it transverse thereto to create a separation between a terminal flake and the remainder of the bale of hay. Those of skill also will appreciate that alternative numbers, materials, dimensions, arcuate or lateral spacings, alignments and configurations of the rollers and the blades mounted thereon are contemplated, and are within the spirit and scope of the invention.
[0026] FIGS. 5A and 5B illustrate the drive mechanism 36 utilized in flaker device 10 to advance an un-stringed or untied bale of hay between flaker wheels 20 and 22 and onto the ground in neat flakes. Drive mechanism 36 in accordance with one embodiment of the invention includes a hydraulic motor 38 w/pressure relief driving a first 3″ sprocket 40 , which in turn drives a 9″ sprocket 42 mounted on one end of a so-called “jack” shaft 44 via a #50 chain 46 . Mounted on the opposite end of jack shaft 44 is a second 3″ sprocket 48 , which in turn drives a third 3″ sprocket 50 via a #80 chain 52 . Third sprocket 48 is mounted on a second shaft 54 , which approximately centrally mounts a fourth 3″ sprocket 56 . Those of skill in the art will appreciate that the size ratio between first 3″ sprocket 40 and 9″ sprocket 42 provides a 3× torque advantage via known mechanical advantage principles, thereby avoiding wearing and bending of the shafts and thereby providing the needed torque to drive mechanism 36 to move a heavy bale of hay through flaker device 10 .
[0027] Those of skill will appreciate that in accordance with another embodiment, motor 38 with sprocket 40 , sprocket 42 , and sprocket 50 can be aligned in a generally horizontal plane at approximately the elevation of an idle sprocket to be described immediately below. Such an elevational placement and alignment somewhat reduces the height of the device and makes it easier to stack and handle during manufacture or transit. This and other improved manufacturability features of the invention (e.g. increased reinforcement of the bed especially where the push arm drive components are mounted; a smooth transition-elevation structure between the bed and the stack mover that accommodates various makes and models thereof for universal compatibility; one or more S-shaped, bed-side-mounted hooks for use in breaking the string on a frozen bale of hay as the bale is conveyed onto the bed; etc.) are contemplated as being within the spirit and scope of the invention.
[0028] Fourth sprocket 56 , as can be seen drives a #80 pusher chain 58 in a loop around a far-end and preferably chain-tension-adjustable fifth #3 idle sprocket 60 . Durably connected to and interrupting pusher chain 58 between two adjacent links thereof is a pusher block 62 . An upward extension of pusher block 62 will be understood to mount push plate 18 via aligned holes formed therein and any suitably secure pin or fastener (not shown). Pusher block 62 includes dual lateral spindles 64 and 66 on either ends of which quad outwardly tapered bushings or rollers 68 , 70 , 72 and 74 freely rotate. Those of skill will appreciate that fore and aft roller pairs such as roller pair 68 , 70 travel within a so-called “ship” channel 75 that extends along a central longitudinal axis of bed 12 of flaker device 10 . In accordance with one embodiment of the invention, channel 75 is slightly tapered outwardly on either end to conformingly fit with the slight outward taper of the rollers 68 , 70 , 72 , 74 . The channel can be made of any suitable material and generally will be understood to have the shape of a rectangle defined by opposite, inwardly facing U-shaped recesses. The bushings or rollers can be made of any suitable material such as bronzed steel.
[0029] Those of skill in the art will appreciate that more or fewer drive and/or idle sprockets are contemplated as being within the spirit and scope of the invention, as is a more direct drive mechanism for advancing the chain and push plate along what may be referred to herein as a hay bale drive mechanism. Those of skill in the art also will appreciate that manufacturability considerations may impact the number and placement of components and their couplings. Thus, changes to the embodiments disclosed and illustrated herein are contemplated, and all such changes in form are within the spirit and scope of the invention.
[0030] Those of skill will appreciate that hydraulic hoses 76 , 78 and associated quick couplers 80 , 82 are used to power hydraulic motor 38 via simple pressure-relief connection with the internal combustion engine of the tow vehicle or other suitable hydraulic pressure source. In accordance with one embodiment of the invention, hydraulic motor 38 is operated at approximately 1000 pounds of pressure to produce approximately 300 pounds of torque. Those of skill in the art also will appreciate that the hay bale “push plate” or “push arm” (driven by drive mechanism 36 across the bed of flaker device 10 ) described and illustrated herein alternatively but within the spirit and scope of the invention could be replaced with a moving conveyor belt so that the lateral conveyance of the hay bale toward the flaker wheels involves moving a surface beneath a stationary hay bale rather than sliding the hay bale across the stationary bed.
[0031] FIGS. 6A , 6 B and 6 C illustrate pusher plate 18 that couples with push block 62 and thus drive mechanism 36 to convey an un-stringed or untied bale of hay between the opposing flaker wheels by sliding the bale along the flaker device's stationary bed. Pusher plate 18 includes an upright planar expanse 84 , a vertical stabilizer 86 and two horizontal stabilizers 88 , 90 . Vertical stabilizer 86 has a guide 91 at its base that keeps vertical stabilizer 86 substantially vertical during its travel along bed 12 . In accordance with one embodiment of the invention, vertical stabilizer 86 has a slight bend on its rear end to act as a dimensionally tolerant guide for the next bale of hay to be loaded on bed 12 , as shown.
[0032] FIGS. 7A and 7B illustrate the pusher block in more detail consistent with FIGS. 5A and 5B , and are believed to be self-explanatory.
[0033] FIGS. 8A , 8 B and 8 C illustrate the front or “fore” board 14 that aligns the un-stringed or untied bale of hay while it is forced between the opposed flaker wheels. Those of skill in the art will appreciate that fore board 14 in accordance with one embodiment of the invention includes a horizontal expanse 92 of any suitable construction, the expanse being mounted and elevated at a desired height above the bed of the flaker device by two L-shaped, preferably square tubular metal arms 94 and 96 . The base of each L-shaped arm is spaced apart and otherwise dimensioned to fit into corresponding square tubular receivers of bed 12 , as will be seen by reference below to FIG. 10B . Those of skill in the art will appreciate that fore board 14 at least nominally (and adjustably—see plural mounting holes in FIG. 8B ) aligns the bale of hay being flaked by flaker device 10 with the opening defined between flaker wheels 20 and 22 . Those of skill in the art will appreciate that the horizontal expanse of fore board 14 can be dimensioned and configured differently from that which is shown in FIGS. 8A , 8 B, and 8 C, within the spirit and scope of the invention, e.g. to further reduce weight and cost or otherwise improve manufacturability.
[0034] FIGS. 9A , 9 B and 9 C illustrate a flaker wheel frame 98 that mounts to the bed of the flaker device and that mounts for free rotation therein two opposing flaker wheels 20 and 22 . Those of skill in the art will appreciate that frame 98 mounts the tops of spindles 25 and 26 for free-wheeling rotation within corresponding cylindrical collars 100 and 102 within square tubular slides 104 and 106 , as shown. The spindles can be positioned and mounted within an elongate hole and any one of plural aligned pairs of slide-mounting holes (see the double-ended arrows) for adjustment of the opening between the flaker wheels to accommodate the nominal width of the bales of hay being flaked. Any suitable hardware including secure pins or fasteners can be used to assemble the preferably standard channel piece and hot-rolled steel piece frame into the upside-down U-shape shown (in side elevation) or any other suitable frame shape.
[0035] FIGS. 10A , 10 B and 10 C illustrate bed 12 of flaker device 10 that mounts frame 98 (not shown in FIGS. 10A , 10 B and 10 C but shown in FIGS. 9A , 9 B and 9 C) and ship channel 75 therein through which pusher block 62 (also not shown in FIGS. 10A , 10 B and 10 C but shown in FIGS. 5A , 5 B, 7 A and 7 B) travels. Those of skill in the art will appreciate that bed 12 has pairs of slotted holes and mounting holes aligned in correspondence to those of frame 12 to mount the bottoms of spindles 25 and 26 for free-wheeling rotation therein. Bed 12 also includes dual laterally spaced, preferably square tubular metal receivers 108 , 110 for securing the horizontal extents of L-shaped 94 and 96 of fore board 14 . Those of skill in the art also will appreciate that any suitable materials can be used to construct bed 12 such as the formed hot-rolled (H.R.) steel pieces called out in the Bill of Materials (BOM).
[0036] It will be understood that the present invention is not limited to the method or detail of construction, fabrication, material, application or use described and illustrated herein. Indeed, any suitable variation of fabrication, use, or application is contemplated as an alternative embodiment, and thus is within the spirit and scope, of the invention.
[0037] From the foregoing, those of skill in the art will appreciate that several advantages of the present invention include the following.
[0038] The present invention avoids manual tools and manual or automatic crushing or stripping of leaves from stems of hay used for livestock feed, thereby increasing the effective delivery of nutrients to livestock such as cattle. The invention provides for the semi-automatic, controlled separation and dispensing of intact hay flakes where needed by simply pushing/pulling a handle or lever. The invention saves time and diesel fuel consumption by reducing many trips between barn and livestock. This is because plural bales are hauled around instead in one or two trips and each is flaked and dispensed exactly where needed. The invented flaker device nevertheless is simple to install, adjust, deploy, operate and maintain.
[0039] It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, method of manufacture, shape, size, or material which are not specified within the detailed written description or illustrations contained herein yet are considered apparent or obvious to one skilled in the art are within the scope of the present invention.
[0040] Accordingly, while the present invention has been shown and described with reference to the foregoing embodiments of the invented apparatus, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
[0041] It will be understood that the present invention is not limited to the method or detail of construction, fabrication, material, application or use described and illustrated herein. Indeed, any suitable variation of fabrication, use, or application is contemplated as an alternative embodiment, and thus is within the spirit and scope, of the invention.
[0042] It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, configuration, method of manufacture, shape, size, or material, which are not specified within the detailed written description or illustrations contained herein yet would be understood by one skilled in the art, are within the scope of the present invention.
[0043] Accordingly, while the present invention has been shown and described with reference to the foregoing embodiments of the invented apparatus, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.
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A chain driven push arm advances a hay bale along a bed toward an opening including a pair of vertically aligned, spaced-apart idle wheels each including plural radiating blades. As the hay bale advances along the bed, the wheels rotate freely causing the blades to impinge on successive regions of the hay bale to separate a succession of flakes from the hay bale remainder. The bed is mounted on a wheeled truck or vehicle that is towable behind a tractor as the tractor driver remotely selectively operates the push arm to dispense flakes along the ground. An optional, towable conveyor can be used to load the bed with a succession of hay bales.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a movable connector, and more particularly to a movable connector operable in high-temperature environments and capable of flexibly absorbing displacements caused when a partner connector is fitted to the movable connector.
2. Description of the Prior Art
In the prior art of connectors having male and female housings which are automatically connected to each other by machinery, such as when wire harnesses are connected to instrumentation during the assembly of automobiles, it has been suggested in Japanese Laid-Open Utility Model Publication No. 59-20578 that one of the housings be made flexibly movable in a panel to absorb any displacements caused when the two housings are fitted together.
As shown in FIG. 5 of Japanese Laid-Open Utility Model Publication No. 59-20578, a connector proposed for the above-mentioned purpose comprises a male housing and a bracket which is formed separately from the male housing. The bracket has fitting portions, which include flexible engagement arms for flexibly supporting the male housing, and mounting members for securing the male connector to a panel.
In the structure described above, the fitting portions and the mounting members enable the male housing to absorb small positional changes when a female housing is joined thereto. However, since the male housing and the bracket are separately formed and assembled together when they are mounted to the panel, the number of parts that need to be manufactured and assembled is unavoidably increased, which results in increased manufacturing costs and assembly time.
Furthermore, according to the structure above, the overall size of the connector has to be made relatively large, and this results in a more complicated manufacturing process.
In response to these problems, an invention was recently disclosed in U.S. Pat. application Ser. No. 07/307,482 for overcoming the disadvantages of the prior art connectors.
As shown in FIG. 1, one embodiment of that invention comprises a movable connector C having a male connector housing 20 to which is fitted a partner female connector housing (not shown). Near the rear portion of the male housing 20 there is formed an annular spring member 14 on each side surface thereof, and between any two spring members 14 there is formed a guide flange 15. The movable connector is constructed such that the annular springs 14 will press against the bottom 8 of a groove 7 formed in an inner edge defining an opening 6 of a panel P for supporting the movable connector A.
In the above structure, the male housing 20 and the annular spring members 14 are formed together as a single unit from a synthetic resin such as a polyamide resin, a polypropylene resin or the like.
The panel P which supports the male housing 20 is comprised of two panels P1 and P2 which are joined together by screws or the like. For accommodating the male housing 20, notches 6a and 6b are formed in the panels P1 and P2, respectively, which fit around the outer periphery of the connecter when the connecter is mounted in the panel P. The notches 6a and 6b comprise the opening 6, with the groove 7 being formed in the inner edges of the panels P1 and P2 that define the notches 6a and 6b.
Thus, when the male housing 20 is mounted in the panel P, the spring members 14 are in flexible abutment with respective surfaces that define the groove bottom 8 of the groove 7. This results in an elastic support for the connector C and permits flexible movement therefor.
Moreover, with the above structure the connector C will be able to flexibly absorb any displacements caused during the fitting of the female housing to the male housing 20 even when the fitting is carried out with minor misalignment of the two housings.
Unfortunately, however, even though the invention described above provides many advantages over the prior art, it has limitations and cannot be used to solve other disadvantages of the prior art connectors.
Namely, due to the structure, and in particular to the resins employed, in high temperature environments, such as engine compartments and the like the spring members 14 will lose some of their springiness and even undergo plastic deformations. This can adversely affect maintenance and refitting of the housings.
Furthermore, in the inadvertent event that the connector is dropped or hit against something, damage will quite likely be inflicted upon the spring members 14.
SUMMARY OF THE INVENTION
In view of disadvantages of the prior art movable connectors and the invention described above, it is an object of the present invention to provide a movable connector having a simple structure which is capable of flexibly absorbing displacements caused when a partner connector is fitted to the movable connector.
It is another object of the present invention to provide a movable connector having a compact and inexpensively producible means for absorbing displacements caused when a partner connector is fitted to the movable connector.
It is a further object of the present invention to provide a movable connector having a displacement absorbing means that can function effectively in high-temperature environments.
It is still another object of the present invention to provide a durable movable connector which is resistent to damage from shocks or forces.
It is still a further object of the present invention to provide a connector which can easily be mounted in a panel.
In order to achieve the above-mentioned objects, the movable connector of the present invention comprises a housing which is flexibly mountable to a panel having an opening formed at a mounting portion thereof. For the purpose of forming a flexible fit with the panel, the connector has a rubber member provided around the connector housing for insertion into a fitting groove formed in an inner edge of the panel defining the opening of the mounting portion. When mounted, the rubber member flexibly abuts the bottom of the fitting groove to enable flexible movement of the connector.
In the present invention, the rubber member is formed as a separate ring-like element that is then stretched over the housing and attached thereto. For supporting the rubber member, guide portions are provided around the side surfaces of the connector housing to form a concave-like passage in which the rubber member resides. In addition, these guide portions serve to abut the side walls of the fitting groove when the connector is mounted to the panel.
For standard type, movable connectors having male and female partner housings, the structure of the connector housing according the present invention can be applied to either housing, but the preferred practice would be to apply this structure to the male housing because the male housing is typically the one that is mounted in a panel.
The foregoing, and other objects, features, and advantages of the present invention will become more apparent from the detailed description of the preferred embodiment taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a movable connector shown in the prior application mentioned above.
FIG. 2 is a perspective view showing a movable connector according to the present invention and a panel to which the movable connector is to be mounted.
FIG. 3 is a front view of a movable connector according to the present invention.
FIG. 4 is a side cross-sectional view showing a female housing in a state of being brought toward engagement with the male housing shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 2, a movable connector A is shown to comprise a male connector housing 1 which is engagable with a female partner housing (not shown). The male housing 1 has a basic rectanguloid shape with front and rear ends and four side surfaces. Near the rear end of the housing 1 on each side surface thereof a pair of thin plate-like guide members 2 is provided so as to be parallel to each other. The guide members 2 are set to have a height H 1 , and taken together the guide members 2 form a concave-like passage 4 over the side surfaces of the male housing 1.
Provided within the passage 4 and supported by the guide members 2 is a ring-like rubber member 5 having a height H 2 greater than the height H 1 of the guide members 2. The rubber member 5 is made as a separate element, which in a non-attached state has a rectangular ring-like shape with four rounded corners. When the rubber member 5 is to be attached to the male housing 1, it is first stretched over the male housing 1 and then mounted within the passage 4. For allowing the movable connector A to be useful in high-temperature environments, the rubber member 5 is made from a rubber material chosen from heat-resistant rubbers such as nitryl-based or fluoro-based rubbers.
At the front end of the male housing 1 there are a plurality of terminal receiving chambers 3, each of which houses a female terminal (not shown) engagable with a corresponding male terminal (not shown) of the female housing of the partner connector. In addition, on one of the side surfaces of the male housing 1 (the top surface as viewed in FIG. 2), a guide ridge 17 is provided for guiding a guide groove (not shown) formed in an inside surface of the female housing, by which it is possible to confirm a proper orientation of the female housing with respect to the male housing 1 when engagement takes place.
Now, with further reference to FIG. 2, a panel P for holding the male housing 1 comprises a fixed panel P 1 and a fitting panel P 2 which is fastenable to the fixed panel P 1 by screws or the like. The panels P 1 and P 2 are provided, respectively, with opposing c-shaped notch portions 6a and 6b which, upon the fastening of the fitting panel P 2 to the fixed panel P 1 , form a closed rectangular space defining the opening portion 6. For allowing displacement of the male housing 1 with respect to the panel P, the opening portion 6 is preferably made to have dimensions slightly larger than those of a cross section of the male housing 1 taken along a plane perpendicular to the side faces thereof.
In the inside edges of the panels P 1 and P 2 that define the notch portions 6a and 6b are formed fitting grooves 7a and 7b, respectively. The fitting grooves 7a and 7b are formed so as to be in alignment with each other in order to define a single rectangular fitting groove 7 when the panels P 1 and P 2 are fastened together. The depth D of the fitting groove 7 is set to lie roughly between the the height H 1 of the guide members 2 and the height H 2 of the rubber member 5. The width of the fitting groove 7 is set such that the outer periphery of the rubber member 5 will abut a groove bottom 8a when the rubber member 5 is inserted into the fitting groove 7.
In fitting the male housing 1 to the panel P, a half portion of the rubber member 5 and guide portions 2 is inserted into the fitting groove 7a of the fixed panel P 1 . Next, the fitting panel P 2 is fitted over the male housing 1 in such a manner that the remaining half portion of the rubber member 5 and guide members 2 becomes inserted into the fitting groove 7b of the fitting panel P 2 . Then, after the panels P 1 and P 2 have been fastened together by the previously mentioned fastening means, the rubber member 5 and the guide members 2 will reside within the fitting groove 7, with the rubber member 5 flexibly abutting the groove bottom 8a of the fitting groove 7.
An example of a mounted state of the male housing 1 within the panel P is illustrated in FIG. 3. As shown in this figure, when the male housing 1 is mounted within the panel P, portions of both the rubber member 5 and the guide members 2 reside within the fitting groove 7. In this example, the portion of each guide member 2 that lies within the fitting groove 7 has length L=H 4 -H 3 , where H 3 and H 4 are the distances measured from the center of the housing 1 to the inner edge of the opening 6 and the ends of the guide members 2, respectively. These portions of the guide members 2 that reside within the fitting groove 7 act as stoppers against the side walls 8b of the fitting groove 7 when the male housing 1 is experiencing any movement in the axial direction, and they are in sliding abutment with the side walls 8b when the male housing 1 is moving within the plane of the panel P.
In the structure described above, the male housing 1 is able to move flexibly by slight amounts so as to absorb any minor forces or shocks imparted thereto. This is a direct result of the compressibility and elasticity of the rubber member 5. In order to better understand how this is done, a specific example explaining the function of the rubber member 5 will be given with reference to FIG. 4.
Namely, in FIG. 4 the movable connector A is shown in a mounted state within the panel P. Also shown is a partner connector B just prior to being fitted to the connector A. The connector B comprises a female housing 10 having a tapered guide 12 forming an opening that leads to a terminal holding chamber 11 in which is provided a plurality of male terminals 13.
Now, in the event that there is any misalignment between the male and female housings 1 and 10 when the female housing 10 is being fitted to the male housing 1, the front end of the male housing 1 will abut the tapered guide 12 of the female housing 10. As a result, the misalignment will give rise to an external force that will try to move the male housing 1 from its normal position within the panel P.
However, in response to this external force, the rubber member 5 will compress against the groove bottom 8a of the fitting groove 7, which will allow the male housing 1 to flexibly move in the direction of the external force and thereby absorb such force. As this happens, the portions of the rubber member being compressed against the groove bottom 8a will undergo elastic deformation, with any excess thickness resulting from such deformation being accommodated by spaces 9 formed between the fitting groove 7 and the guide members 2. Then when the external force has subsided, the rubber member 5 will regain its normal shape and thereby return the male housing 1, together with the fitted female housing 10, to its normal position.
Thus, in concert with the objectives stated above, it is possible to provide a movable connector which is capable of flexibly absorbing displacements caused when a partner connector is fitted to the movable connector. Moreover, as the function of the rubber member remains unchanged even after the two housings are fitted together, the joined connectors can flexibly move to absorb any forces or shocks caused by such things as the connectors being struck or the connector wires being pulled.
In addition, since the rubber member is made from a heat-resistant rubber, the connector can be employeed in high-temperature environments, such as the engine compartment of an automobile, without losing its effectiveness and with no worry of heat-induced deformations. As a result, maintenance and replacement are very easy to perform.
Furthermore, the present invention includes the function of protecting the connector against inadvertent damage that might occur even before the connector is mounted within the panel. This is because the rubber member acts, as an elastic padding that surrounds and cushions the connector against accidental drops or other such physical shocks.
Lastly, it is to be understood that even though the present invention has been described according to its preferred embodiment, many modifications and improvements may be made without departing from the scope of the invention as defined in the appended claims.
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A movable connector having a movable housing which is to be secured to a panel is provided with a rubber member for insertion into a fitting groove formed in the panel. The rubber member serves to flexibly absorb displacements caused when a partner housing from a partner connector is fitted to the movable housing and also acts as a protective cushioning to prevent damage from occuring to the movable connector. In addition, by choosing a heat-resistant material for the rubber member, the movable connector can be effectively utilized in high-temperature environments.
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CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
FIELD OF THE INVENTION
The present invention relates to a process for the preparation of synthesis gas (i.e., a mixture of carbon monoxide and hydrogen), typically labeled syngas. More particularly, the present invention relates to novel methods of regenerating a partial oxidation catalysts via chemical re-dispersion of the catalytic metals. In addition, the present invention can be used for in-situ regeneration of a partial oxidation catalyst without any downtime in production.
BACKGROUND OF THE INVENTION
Catalysis is literally the lifeblood for many industrial/commercial processes in the world today. The most important aspect of a catalyst is that it can increase the productivity, efficiency and profitability of the overall process by enhancing the rate, activity and/or selectivity of a given reaction. Many industrial/commercial processes involve reactions that are simply too slow and/or inefficient to be economical without a catalyst present. For example, the process of converting natural gas or methane to liquid hydrocarbons (an extremely desirable process) necessarily involves several catalytic reactions.
The conversion of methane to hydrocarbons is typically carried out in two steps. In the first step, methane is catalytically converted to carbon monoxide and hydrogen (i.e., synthesis gas or syngas). In a second step, the syngas intermediate is catalytically converted to higher hydrocarbon products by processes such as the Fischer-Tropsch Synthesis or to other chemicals by processes such as an alcohol synthesis. For example, fuels such as hydrocarbon waxes and liquid hydrocarbons comprised in the middle distillate range, i.e., kerosene and diesel fuel, may be produced from the synthesis gas.
Current industrial use of methane as a chemical feedstock for syngas production proceeds by the initial conversion of methane to carbon monoxide and hydrogen by either steam reforming or dry reforming. Steam reforming currently is the major process used commercially for the conversion of methane to synthesis gas, the reaction proceeding according to Equation 1.
CH 4 +H 2 O CO+3H 2 (1)
The catalytic partial oxidation (“CPOX”) of hydrocarbons, e.g., methane or natural gas, to syngas has also been described in the literature. In catalytic partial oxidation, natural gas is mixed with air, oxygen-enriched air, or oxygen, and introduced to a catalyst at elevated temperature and pressure. The partial oxidation of methane yields a syngas mixture with a more preferable H 2 :CO ratio of 2:1, as shown in Equation 2:
CH 4 +1/2O 2 CO+2H 2 (2)
The H 2 :CO ratio for this reaction is more useful for the downstream conversion of syngas to fuels or to chemicals such as methanol than is the H 2 :CO ratio from steam reforming. However, both reactions continue to be the focus of research in the world today.
As stated above, these reactions are catalytic reactions and the literature is replete with varying catalyst compositions. The catalyst compositions typically are comprised of at least one catalytically active metal, such as a Group VIII metal. Many catalyst compositions also have other promoters present. Catalytic metals are typically selected based on their activity and selectivity towards a particular reaction. Further, the catalyst compositions typically include particular support materials such as alumina, silica, titania, etc., that can also enhance the catalyst activity.
After a period of time in operation, a catalyst will become deactivated, losing its effectiveness for catalyzing the desired reaction to a degree that makes the process uneconomical at best and inoperative at worst. This process is generally known as “aging.” The more aged a particular catalyst the less efficient the catalyst is at enhancing the reaction, i.e., less activity it has. At this point, the catalyst can be either replaced or regenerated. However, replacing a catalyst typically means discarding the deactivated catalyst. Even if a fresh replacement catalyst is ready and available, a single syngas reactor will typically have to be shut down and offline for days to weeks. The time delay is due at least in part to the time required for simple cooling and heating of the reactor.
In addition, a discarded catalyst represents a loss of expensive metals. Alternatively, the user may send the catalyst back to the supplier for recovery of expensive metals, such as Rh, Pt, Pd, etc. However, the recovery process involves dissolving the multi-component catalyst and subsequent separation of the active components from the mixed solution. The chemistry is complex and costly, more importantly, it involves bulk amounts of harsh chemicals that ultimately must be discarded and the use of landfills for such disposal is problematic. For example, the environmental protection agency (EPA) “Land Ban” imposes restrictions on disposal because these harsh chemicals can release toxins into the environment. For all of these reasons, regeneration is preferred over replacement.
However, regeneration has problems as well. Like replacement, regeneration typically requires some downtime resulting in a decrease in production. In addition, regeneration may not be available for every deactivated catalyst. Catalyst systems can become deactivated by any number of mechanisms. Some of the more common deactivating mechanisms include coking, sintering, poisoning, oxidation, and reduction. The process chiefly responsible for deactivation varies among catalyst systems. Some catalysts that have been deactivated can be regenerated and/or the deactivation reaction can be reversed. However, many regeneration processes are not economically feasible.
Sintering as a cause of deactivation traditionally has been viewed as a non-reversible phenomenon, since a sintered catalyst is particularly difficult to regenerate. In terms of synthesis gas catalysts, sintering is usually the result of the high temperatures within the catalyst bed. The syngas reactions achieve very high temperatures during operation. Temperatures within a syngas catalyst bed typically reach temperatures in excess of 1000° C. Sintering for syngas catalysts is therefore practically unavoidable. There are similarly potential deactivation issues with other catalytic partial oxidation reactions that take place at high temperature.
Because regeneration has traditionally been so difficult, the active metals are typically dissolved and recaptured for use in new catalyst batches. However, research is continuing on the development of more efficient syngas catalyst systems and catalyst systems that can be more effectively regenerated. To date there are no known methods that are economically feasible for regenerating a partial oxidation catalyst, such as a syngas catalyst.
Hence, there is still a great need to identify new regeneration methods, particularly methods that are quick and effective for regenerating deactivated partial oxidation catalysts without having to dissolve the catalyst components and without significant downtime or loss of production.
SUMMARY OF THE INVENTION
The present invention relates to a process for the preparation of synthesis gas (i.e., a mixture of carbon monoxide and hydrogen), typically labeled syngas. More particularly, the present invention relates to novel methods of regenerating partial oxidation catalysts via chemical re-dispersion of the catalytic metals. In addition, the present invention can be used for in-situ regeneration of a partial oxidation catalyst with little to no downtime in production.
The regeneration of the partial oxidation catalysts is accomplished by passing a gas over a deactivated catalyst that restores the catalytic metal to its active form and/or restores active surface area of the catalytic metals lost from deactivation phenomenon. Suitable regeneration gases include but are not limited to carbon monoxide, hydrogen, oxygen, syngas and steam. The present invention is primarily directed towards partial oxidation catalysts used preferably in partial oxidation reactions of hydrocarbons or hydrogen sulfide or combinations and even more preferably used in syngas catalysts that contain Group VIII, noble metals or combinations thereof.
Sometimes it may be necessary or just advantageous to use a multiple step regeneration process in which the deactivated catalysts are exposed to more than one type of gas in a stepwise fashion. For example, one embodiment of the present invention would be to expose the deactivated partial oxidation catalyst to an oxidizing gas followed by a reducing gas.
In yet another preferred embodiment of the present invention, a synthesis gas reaction is carried out producing primarily hydrogen and carbon monoxide, i.e., syngas. A slip stream of the syngas product is removed, resulting in a primary syngas product stream and a small secondary syngas stream, the slip stream. The slip stream is separated to produce a hydrogen rich stream and a carbon monoxide rich stream. The hydrogen rich stream can then be used for in-situ regeneration or activation of a second partial oxidation catalyst. The excess hydrogen rich gas from the regeneration or activation process can be re-introduced into the primary syngas stream from the first reactor along with the carbon monoxide rich stream. The primary syngas stream can then be introduced into a Fischer-Tropsch reactor to produce liquid hydrocarbons.
In the most preferred embodiment of the present invention, more than one partial oxidation reactor is used, allowing continuous production even during the regeneration process. For example, one syngas reactor produces syngas, which in turn is partially used to obtain a hydrogen rich regeneration gas. The hydrogen rich gas is passed over the deactivated catalyst in a second syngas reactor for regeneration. When the catalyst in the first syngas reactor is deactivated, the process can be reversed. The second syngas reactor produces the syngas and thus hydrogen rich gas. The hydrogen rich gas is then used to regenerate the catalyst in the first syngas reactor. This type of cycle can be repeated indefinitely or until the catalyst can no longer be regenerated.
These and other embodiments, features and advantages of the present invention will become apparent with reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the preferred embodiment of the present invention reference will now be made to the accompanying Figures,
FIG. 1 is a block flow diagram of a hydrocarbon gas to liquid conversion process in accordance with one embodiment of the present invention; and
FIG. 2 is a block flow diagram of a hydrocarbon gas to liquid conversion process in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
There are shown in the Figures, and herein will be described in detail, specific embodiments of the present invention, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. The present invention is susceptible to embodiments of different forms or order and should not be interpreted to be limited to the particular structures or compositions contained herein. In particular, various embodiments of the present invention provide a number of different configurations of the overall gas to liquid conversion process.
The regeneration of a partial oxidation catalyst is accomplished by passing a gas over a deactivated catalyst that restores the catalytic metal to its active form and/or restores active surface area of the catalytic metals lost from deactivation phenomenon. The present invention is primarily directed towards partial oxidation catalysts used in partial oxidation reactions of hydrocarbons or hydrogen sulfide or combinations thereof and even more preferably towards catalysts that contain Group VIII or noble metals that are used in partial oxidation reactions of natural gas or methane to produce syngas. The partial oxidation catalyst preferably contains one or more of the following metals: rhodium, ruthenium, platinum, palladium, iridium, nickel, cobalt, with optional promoters.
According to the present invention, a syngas reactor can comprise any of the synthesis gas technology and/or methods known in the art. The hydrocarbon-containing feed is almost exclusively obtained as natural gas. However, the most important component is generally methane. Methane or other suitable hydrocarbon feedstocks (hydrocarbons with four carbons or less) are also readily available from a variety of other sources such as higher chain hydrocarbon liquids, coal, coke, hydrocarbon gases, etc., all of which are clearly known in the art. Similarly, the oxygen-containing gas may come from a variety of sources and will be somewhat dependent upon the nature of the reaction being used. For example, a partial oxidation reaction requires diatomic oxygen as a feedstock, while steam reforming requires only steam. According to the preferred embodiment of the present invention, partial oxidation is assumed for at least part of the syngas production reaction.
Regardless of the source, the hydrocarbon-containing feed and the oxygen-containing feed are reacted under catalytic conditions. The catalyst compositions useful for synthesis gas reactions are well known in the art. They generally are comprised of a catalytic metal that has been reduced to its active form and one or more promoters on a support structure. The most common catalytic metals are Group VIII metals or noble metals. The support structures may be monoliths, wire mesh or particulates. Often, the support selected will dictate the type of catalyst bed that must be used. For example, fixed beds are comprised of monoliths and large particle sized supports. Supports comprised of small particles tend to be more useful in fluidized beds. The support matrix is usually a metal oxide or mixture of metal oxides, such as alumina, titania, zirconia, or the like.
The synthesis gas feedstocks are generally preheated, mixed and passed over or through the catalyst beds. As the mixed feedstocks contact the catalyst, the synthesis reactions take place. The synthesis gas product contains primarily hydrogen and carbon monoxide, however, many other minor components may be present including steam, nitrogen, carbon dioxide, ammonia, hydrogen cyanide, etc., as well as unreacted feedstock, such as methane and/or oxygen. The synthesis gas product, i.e., syngas, is then ready to be used, treated, or directed to its intended purpose. For example, in the instant case some or all of the syngas may be used to prepare regeneration gases for the present invention or may be used as a feedstock for a Fischer-Tropsch process or an alcohol synthesis plant.
The syngas-containing stream when leaving a syngas reactor is typically at a temperature of about 600–1500° C. The syngas must be transitioned to be useable in synthesis reactor downstream of the syngas reactor such as a Fischer-Tropsch or other synthesis reactors e.g. an alcohol synthesis reactor, which operate at lower temperatures of about 200° C. to 400° C. The syngas is typically cooled, dehydrated (i.e., taken below 100° C. to knock out water) and compressed during the transition phase. Thus, in the transition of syngas from the syngas reactor to a synthesis reactor, the syngas stream may experience a temperature window of 50° C. to 1500° C.
Several reactions have been discovered that can restore the activity to a deactivated syngas catalyst depending on the deactivation phenomenon. The applicants believe that the methods disclosed herein to regenerate a syngas catalyst are applicable to any partial oxidation catalyst, which loses its activity due to the same or similar deactivation mechanisms. For example, catalytic metals are often oxidized as a result of the syngas reaction, which results in at least two problems, namely, the loss of the “active state” (reduced) of the catalytically active metals, and the loss of catalytically active surface area. Noble metals are preferred as the primary catalytic metals for syngas catalyst compositions. Noble metals form metal oxides under syngas reactor conditions. In addition, the preparation of a noble metal-containing syngas catalyst often includes at least one calcining step that will oxidize the noble metal. Calcination results in metal oxides. Thus, sometimes the catalytic metals are not in the fully active form even before exposure to the syngas reactions. In any event, the noble metal oxides will still catalyze the syngas reaction, however, the activity of the reduced metal, generally considered the active species, is greatly preferred.
Also, oxidation of the syngas catalytic metals can result in the loss of catalytically active surface area. As the noble metal oxides are formed, other oxides can be forming simultaneously, i.e., oxides of secondary catalytic metal or promoter metal. Due to the mobility of these metal particles, the noble metals are often physically “covered” by other metal oxides, further decreasing the amount of active surface area available for catalytic participation.
Thus, according to one embodiment of the present invention, a hydrogen-rich gas is passed over deactivated syngas catalysts as the primary regeneration gas. It is believed that the hydrogen exposure results in at least one of two phenomena that can help restore the activity back to the overall catalyst composition. First, the oxidized noble metal particles are “uncovered” or brought back toward to the surface of the support. “Surface” in this context is intended to mean the place where the metal particle will have exposure to the reactant gases. In other words, surface is not limited to the outer surface of a spherical support particle, and could also be the inner surface of a pore or microfracture within the support particle or structure such that the syngas reactants could be exposed to the particle and react. The catalytic metals tend to migrate towards the surface and are reduced under the hydrogen gas. Second, as the hydrogen reduction reaction reduces the metal particles they re-disperse. Thus, more of the noble metal particles are reduced to the more active form and dispersed on and through the support to achieve the high amount of surface area needed for the syngas reaction.
The hydrogen rich gas may be obtained or produced from any available source including, but not limited to, recycled gas streams, bottled gas, produced syngas, Fischer-Tropsch tailgas, hydroprocessing tailgas, hydrogen-rich streams from an alcohol synthesis plant, an olefin synthesis plant, a carbon filaments/carbon fibers synthesis plant, an aromatic synthesis plant, or the like. The purity of the hydrogen rich gas is not critical, but it is preferred that the hydrogen rich gas be oxygen free. A secondary preference is that the hydrogen rich gas be also carbon free. It will be understood by those skilled in the art that gases cannot ever be absolutely free of impurities, including oxygen or carbon. Likewise, the present invention does not assert or contemplate such an extreme position. It is intended that these impurities are substantially eliminated to the point that side reactions associated with their presence do not significantly alter or inhibit the effective regeneration of the catalyst metal according to the present invention.
According to another embodiment of the present invention, a hydrocarbon-rich gas is passed over deactivated partial oxidation catalysts as the primary regeneration gas. Preferably the hydrocarbon-rich gas is natural gas, mixtures of C 1 –C 10 hydrocarbons, methane, or combinations thereof. It is believed that the hydrocarbon-rich gas creates a reducing environment thereby reducing the metal particles.
FIG. 1 shows a block flow diagram in accordance with one preferred embodiment of the present invention. The flow diagram is of a gas to liquid conversion process that includes a method for in-situ regeneration or activation of a syngas catalyst. Syngas can be generated by a catalytic reaction between a hydrocarbon-containing gas and an oxygen-containing gas and optionally steam. The hydrocarbon containing gas can be any hydrocarbon containing gas in which the hydrocarbon content is substantially C 4 or less. The more preferred hydrocarbon containing gases are natural gas or methane. The oxygen containing gas can be air or oxygen and is preferably oxygen.
The hydrocarbon containing gas and oxygen containing gas (collectively “syngas feedstock”) are introduced into a first syngas reactor 100 through line 105 . It should be appreciated that these gases are typically mixed very near in time to exposure to the syngas catalyst. FIG. 1 is intended merely as a flow diagram and not intended to disclose these kinds of details that are well known in the art and by those of ordinary skill. The syngas feedstocks are catalytically reacted in a first syngas reactor 100 to produce primarily hydrogen and carbon monoxide, i.e., syngas.
The produced syngas exits through line 110 and is then passed to a Fischer-Tropsch reactor 145 via line 120 . Again, it should be appreciated that other details such as preparation of the syngas as a Fischer-Tropsch feedstock in terms of temperature, pressure, water knock-out, etc., are presumed to be understood by those of ordinary skill in the art.
A slip stream of syngas is removed from line 110 and passed into a gas separation unit 125 through line 115 . The type of separation used in unit 125 is not critical to the present invention and may include any physical and/or chemical means of separation such as membranes, adsorption-desorption techniques, water gas shift reactors, and the like. In the most preferred embodiment, gas separation unit 125 comprises a membrane separator. Membranes are well known in the art to be highly selective to hydrogen, typically greater than 70%. With the hydrogen removed, the remaining syngas will be carbon monoxide rich. Thus, the gas separation unit 125 produces a hydrogen rich permeate stream and a carbon monoxide rich stream.
The carbon monoxide rich stream exits the gas separation unit 125 through line 135 . The carbon monoxide rich stream can be sent to flare, used as a feedstock or reactant for various reactions, but is preferably re-introduced into line 120 .
In accordance with the most preferred embodiment of the present invention, the hydrogen rich permeate stream is removed and introduced into a second syngas reactor 150 via line 130 . The hydrogen rich gas is passed over a syngas catalyst located within second syngas reactor 150 for regeneration or activation of the syngas catalyst. The excess hydrogen rich gas will pass through the second syngas reactor 150 and exit though line 140 . The excess hydrogen rich gas will then preferably be re-introduced into line 120 .
Regulation of lines 135 and 140 can be used to adjust the hydrogen to carbon monoxide molar ratio in primary syngas stream 120 prior to introduction into the Fischer-Tropsch reactor 145 . For example, if more hydrogen is needed in the primary syngas stream 120 , the carbon monoxide rich gas 135 will be decreased by lowering the flow rate, sending some or all to flare, or simply redirecting the gas for other purposes. As the flow rate of carbon monoxide stream 135 is decreased, the flow rate of hydrogen rich stream 140 will be increased as needed to achieve the desired ratio. Likewise, more carbon monoxide can be added from line 135 and less hydrogen from line if the reverse situation is desired. By re-introducing the carbon monoxide and hydrogen rich streams 135 and 140 , respectively, the present invention has the advantage of regenerating the deactivated catalyst using readily available in-house gases while losing very little in terms of final products.
According to the present invention, the time necessary for in-situ regeneration of the syngas catalyst in reactor 150 will be primarily dependent on the volume of catalyst and flow and concentration of hydrogen passing over the catalyst. Under normal operating conditions, i.e., the space velocities for the gas flow, stated as gas hourly space velocity (GHSV), are from about 20,000 to about 100,000,000 hr −1 , preferably from about 100,000 to about 25,000,000 hr −1 a temperature of about 25° C. to about 1500° C., preferably less than 1000° C., more preferably less than 600° C., and a pressure of about 25 psig to about 250 psig, it is anticipated that the time necessary to regenerate a catalyst bed of less than 1 foot in length will be less than 24 hours. Once regenerated, the second syngas reactor 150 can be used to produce syngas for the regeneration of the catalyst in the first syngas reactor 100 when the catalyst becomes deactivated. The process described above is simply reversed as described below.
The syngas feedstocks are introduced into the second syngas reactor 150 through line 155 . The syngas feedstocks are catalytically reacted in syngas reactor 150 to produce syngas. The produced syngas exits through line 160 and is then passed to a synthesis reactor 195 via line 170 . A slip stream of syngas is removed from line 160 and passed into a regenerating gas recovery separation unit 175 through line 165 . Again, the type of separation and/or purification used is not critical to the present invention and may include any physical and/or chemical means of separation such as membranes, adsorption-desorption techniques, water gas shift reactors, and the like. Thus, the gas separation unit 175 will produce a hydrogen rich permeate stream and a carbon monoxide rich stream.
The carbon monoxide rich stream exits the gas separation unit 175 through line 185 . The carbon monoxide rich stream can be sent to flare, used as a feedstock or reactant for various reactions, but is preferably re-introduced into line 170 .
In accordance with the most preferred embodiment of the present invention, the hydrogen rich permeate stream is removed and introduced into the first syngas reactor 100 via line 180 . The hydrogen rich gas is passed over a syngas catalyst located with the first syngas reactor 100 for regeneration or activation of the syngas catalyst. The excess hydrogen rich gas will pass through the first syngas reactor 100 and exit though line 190 . The excess hydrogen rich gas will then preferably be re-introduced into line 170 .
As before, regulation of lines 185 and 190 can be used to adjust the hydrogen to carbon monoxide molar ratio in the primary syngas stream 170 prior to introduction into the synthesis reactor 195 . For example, if more hydrogen is needed in the primary syngas stream 170 , the carbon monoxide rich gas 185 will be decreased by lowering the flow rate, sending some or all to flare, or simply redirecting the gas for other purposes. As the flow rate of carbon monoxide stream 185 is decreased, the flow rate of hydrogen rich stream 190 will be increased as needed to achieve the desired ratio. Likewise, more carbon monoxide can be added from line 185 and less hydrogen from line 190 if the reverse situation is desired.
The synthesis reactor 145 or 195 can comprise any of the Fischer-Tropsch technology and/or methods known in the art. The Fischer-Tropsch feedstock is hydrogen and carbon monoxide, i.e., syngas. The hydrogen to carbon monoxide molar ratio is generally deliberately adjusted to a desired ratio of approximately 2:1, but can vary between 0.5 and 4. The syngas is then contacted with a Fischer-Tropsch catalyst. Fischer-Tropsch catalysts are well known in the art and generally comprise a catalytically active metal, a promoter and a support structure. The most common catalytic metals are Group VIII metals, such as cobalt, nickel, ruthenium, and iron or mixtures thereof. The support is generally alumina, titania, zirconia or mixtures thereof. Fischer-Tropsch reactors use fixed and fluid type conventional catalyst beds as well as slurry bubble columns. The literature is replete with particular embodiments of Fischer-Tropsch reactors and Fischer-Tropsch catalyst compositions. As the mixed feedstocks contact the catalyst the hydrocarbon synthesis reactions take place. The Fischer-Tropsch product contains a wide distribution of hydrocarbon products from C 5 to greater than C 100 .
The Synthesis reactor 145 or 195 can comprise any of the reactors known in the art, which produce alcohols, particularly methanol when using syngas as feedstock.
It should be appreciated that other suitable reducing gases, such as methane, natural gas, light hydrocarbons, can be used to perform the regeneration step. If methane were the regeneration gas selected, the oxygen feedstock would be reduced or eliminated to create a substantially methane stream into the deactivated syngas catalyst bed. Alternatively, the methane may come from stored gas, bottled gas or a slip stream of methane gas from some other source, such as a separate feedstock stream from a second syngas reactor. Also, unreacted methane may be recovered and used from tail-gas of any available process.
In another embodiment of the present invention, the regeneration process described above may use oxidative gases for regeneration rather than reducing gases, such as oxygen, steam or air, with or without other inert gases for safety/dilution purposes. Referring now to FIG. 2 , an in-situ process using oxygen would be possible in which a hydrocarbon containing gas and oxygen containing gas are introduced into a first syngas reactor 200 through line 205 . The syngas feedstocks are catalytically reacted in a first syngas reactor 200 to produce primarily hydrogen and carbon monoxide, i.e., syngas.
The produced syngas exits through line 210 and is then passed to a synthesis reactor 245 via line 220 . At least a portion of the syngas, preferably the entire stream, is passed into a gas separation unit 225 . The type of separation used in unit 225 is not critical to the present invention and may include any physical and/or chemical means of separation such as oxygen selective membranes and any other techniques known or used in the art. In the most preferred embodiment, gas separation unit 225 comprises a membrane separator. Membranes are well known in the art to be highly selective to oxygen, typically greater than 70%. Thus, the gas separation unit 225 produces an oxygen rich stream 230 and a secondary syngas stream 235 . The secondary syngas stream exits the gas separation unit 225 through line 235 and is sent to the synthesis reactor 245 .
In accordance with the most preferred embodiment of the present invention, the oxygen rich stream is removed and introduced into a second syngas reactor 250 via line 230 . The oxygen rich gas is passed over a syngas catalyst located within second syngas reactor 250 for regeneration or activation of the syngas catalyst. The excess oxygen rich gas will pass through the second syngas reactor 250 and exit though line 240 . The excess oxygen rich gas can be recycled and used as syngas feedstock, sent to flare, or released into the atmosphere.
According to the present invention, the time necessary for in-situ regeneration of the syngas catalyst in reactor 250 will be primarily dependent on the volume of catalyst and flow and concentration of hydrogen passing over the catalyst. Under normal operating conditions, i.e., the. space velocities for the gas flow, stated as gas hourly space velocity (GHSV), from about 20,000 to about 100,000,000 hr −1 , preferably from about 100,000 to about 25,000,000 hr −1 a temperature of about 25° C. to about 1500° C., preferably less than 1000° C., more preferably less than 600° C., and a pressure of about 25 psig to about 250 psig, it is anticipated that the time necessary to regenerate a catalyst bed of less than 1 foot in length will be less than 24 hours. Once regenerated, the second syngas reactor 250 can be used to produce syngas for the regeneration of the catalyst in the first syngas reactor 200 when the catalyst becomes deactivated. The process described above is simply reversed as described below.
The syngas feedstocks are introduced into the second syngas reactor 250 through line 255 . The syngas feedstocks are catalytically reacted in syngas reactor 250 to produce syngas. The produced syngas exits through line 260 and is then passed into a gas separation unit 275 . Thus, the gas separation unit 275 will produce an oxygen rich stream 280 and a secondary syngas stream 285 . The secondary syngas stream exits the gas separation unit 275 through line 285 and is sent to the synthesis reactor 295 .
The oxygen rich stream is removed and introduced into the first syngas reactor 200 via line 280 . The oxygen rich gas is passed over a syngas catalyst located with the first syngas reactor 200 for regeneration or activation of the syngas catalyst. The excess oxygen rich gas will pass through the first syngas reactor 200 and exit though line 290 . The excess oxygen rich gas can be recycled and used as syngas feedstock, sent to flare, or released into the atmosphere.
The synthesis reactor 245 or 295 can comprise any of the Fischer-Tropsch technology and/or methods known in the art as described above with respect to the regeneration embodiment using hydrogen.
Alternatively, the regeneration process may be carried out with a single syngas reactor design. For example, in another embodiment of the present invention, a single syngas reactor can be operated in cyclic mode in which the reactor simply alternates between reaction and regeneration operating conditions. The regeneration gas needed for the process may come from bottled gas or other suitable regeneration gases available from other plant processes on site. Once deactivation of a catalyst is detected, the syngas reactant feedstocks would be replaced with the available regeneration gas for a period of time sufficient to restore some or all of the activity to the deactivated catalyst. It should be appreciated that with a given volume, type and composition of catalyst, the necessity for a regeneration cycle can become quite predictable. Thus, no actual detection of deactivation is necessary, simply the understanding that at some given point in time a regeneration cycle is warranted and can be carried out. It is believed that this process would be necessary only on a weekly if not longer basis, resulting in very little down time for syngas production. In addition, depending upon the flow rates and volume of the syngas catalyst bed, the downtime should be insignificant against the total time for available for production. For example, a regeneration cycle may constitute only a three-hour period of time in an entire week.
In another embodiment of the present invention, a multiple step regeneration process may be used. Preferred steps would be to subject the deactivated catalyst first to oxidation by exposure to an oxidizing gas, such as water, steam, oxygen, air, etc., followed by a reduction step by exposure to a reducing gas, such as methane or hydrogen. Air and methane are the preferred gases due to their low cost and availability. This type of multiple step regeneration can be performed under the multiple reactor design or when using a single reactor in cyclic mode. In addition, one of ordinary skill in the art could easily apply the spirit of the embodiments as described in connection with the flow diagrams of FIGS. 1 and 2 to produce a combined process for in-situ multiple step regeneration. For example, the syngas lines exiting the syngas reactors could have a valve that allowed the syngas product to be sent either to a hydrogen separation unit or an oxygen separation unit such that the appropriate regeneration gas could be obtained for the process.
The present invention will be more easily and fully understood by the following example. The example is representative of the regeneration process in accordance with one embodiment of the preferred present invention.
EXAMPLE
A 4 wt % Rh/4 wt % Sm catalyst was tested at a natural gas:oxygen ratio of 1.82:1 at weight hour space velocities (WHSV) of 530 and 940 hr −1 and pressures of 45 and 90 psig (412 and 722 kPa), respectively. The weight hour space velocity is defined by the weight of reactant feed per hour divided by the weight of catalyst. The partial oxidation reaction was carried out in a conventional flow apparatus using a 12.7 mm I.D. quartz insert embedded inside a refractory-lined steel vessel. The quartz insert contained a catalyst bed containing a 9.5 mm catalyst bed held between two inert 80 ppi alumina foams. The reactor effluent was analyzed using a chromatograph equipped with a thermal conductivity detector.
The catalyst was tested for 24 hours at 45 psig (412 kPa), after which a pressure drop of 3.3 psi was observed. The pressure was then increased to 90 psig (722 kPa) for 1.5 hours and an increase in pressure drop to 6.2 psi was observed, as shown in Table 1. An increase in pressure is indicative of at least one deactivation phenomenon, i.e., carbon deposition. Consequently, at the point of the increase in pressure drop, the methane conversion as well as the CO and H 2 selectivity values were decreasing. The reaction was quenched. The catalyst was then treated with 18% molar oxygen in nitrogen for 1-hour at 300° C. and the syngas reaction was re-initiated at a pressure of 90 psig. A pressure drop of 4.0 psi was observed immediately upon re-initiation. After 19 hours of syngas production, the pressure drop had leveled out at 2.5 psi, indicating that the syngas reactant feeds were able to continue the process of improving pressure drop and methane conversion that was initiated by the 1-hour oxygen treatment.
TABLE 1
Pressure
CH 4
Selectivity
Drop (psi)
Conv.
CO
H 2
After 24 hours at 45 psig
3.3
86.1
92.9
89.6
After an additional 1.5
6.2
84.5
91.1
86.7
hours at 90 psig
Reaction quenched
—
—
—
—
Upon re-initiation of syngas
4.0
85.5
92.6
88.4
production after 1 hour O 2
treatment
19 hours after re-initiation
2.5
87.1
94.1
90.5
of syngas production
The data presented herein shows that the present invention is an improved process for the optimal production of a partial oxidation reactor. The data conforms to one of the preferred embodiments for optimizing a partial oxidation process. The optimization process comprises operating a partial oxidation reactor such that: (a) for some time, t 1 , the reactor is fed a gas comprising hydrocarbon and oxygen and produces a product comprising synthesis gas at a pressure greater than or equal to at least two times ambient pressure, and (b) for some time, t 2 , the catalyst in the reactor is regenerated using a regeneration gas, wherein the optimum operation occurs where t 1 is greater than or equal to twice t 2 and t 1 is greater than or equal to 24 hours. All other parameters are consistent with the preferred embodiments described herein. For example, the regeneration gas for the optimization process comprises one or more gases selected from the group consisting of oxygen, carbon monoxide, hydrogen and hydrocarbons.
It should be noted that the invention further includes an arrangement where at least a portion of any unused or produced gas from the regeneration reaction may be recycled into the syngas produced by a syngas reactor.
While preferred embodiments of this invention have been shown and described, modification thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. For example, while syngas and Fischer-Tropsch reactions are explicitly referred to as part of the preferred embodiments, it is clear that any partial oxidation catalyst reactions and hydrocarbon or alcohol reactions, respectively, may be substituted without departing from the spirit of the invention. Many other variations and modifications of the system and apparatus are possible and are within the scope of this invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims, which follow, the scope of which shall include all equivalents of the subject matter of the claims. In particular, unless order is explicitly recited, the recitation of steps in a claim is not intended to require that the steps be performed in any particular order, or that any step must be completed before the beginning of another step.
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The present invention relates to a process for the preparation of synthesis gas (i.e., a mixture of carbon monoxide and hydrogen), typically labeled syngas. More particularly, the present invention relates to a regeneration method for a syngas catalyst. Still more particularly, the present invention relates to the regeneration of syngas catalysts using a re-dispersion technique. The re-dispersion technique involves the formation and removal of carbonyls with the active metals. The carbonyl formation and removal effectively re-disperses the catalyst metal.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. Ser. No. 14/577,118 filed Dec. 19, 2014, now allowed, which is a divisional application of U.S. Ser. No. 13/511,474 filed Jun. 8, 2012, now U.S. Pat. No. 8,916,533 issued Dec. 23, 2014, which claims priority to PCT/US2010/057758 filed Nov. 23, 2010, which claims the benefit of U.S. Provisional Application No. 61/263,655, filed Nov. 23, 2009, the disclosure of which is incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] This invention was not made with any government support and the government has no rights in this invention.
FIELD OF THE INVENTION
[0003] This invention relates generally to the field of molecular biology. More particularly, it concerns cancer-related technology. Certain aspects of the invention include application in diagnostics, therapeutics, and prognostics related to miR-221 and miR-222. In particular liver cancer and lung cancer diagnostics, therapeutics and prognostics are discussed herein.
[0004] The present invention is partially based on the discovery that: binding of hepatocyte growth factor to the hepatocyte growth factor receptor (MET) upregulates phosphorylation of an extracellular signal-regulated kinase (ERK½) and Jun N-termal kinase (JNK), which, in turn, upregulates Jun transcriptional activation, which, in turn, upregulates expression of non-coding microRNAs (miR-221 and miR-222), which, in turn, down regulate sexpression of phosphatase and tensin homolog (PTEN) and tissue inhibitor of metalloproteinase 3 (TIMP3), which, in turn, confers resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cell death and enhances tumorigenicity of lung and liver cancer cells.
[0005] The present invention provides research tools, diagnostic methods, and therapeutical methods and compositions using the knowledge derived from this discovery. The invention is industrially applicable for the purpose of sensitizing tumor cells to drug-inducing apoptosis and also to inhibit tumor cell survival, proliferation and invasive capabilities.
BACKGROUND OF THE INVENTION
[0006] Despite advances in early detection and standard treatment, non small cell lung cancer (NSCLC) and hepatocellular carcinoma (HCC), are often diagnosed at an advanced stage and have poor prognoses. Promoting apoptosis is a possible goal for drug development. TNF-related apoptosis-inducing ligand (TRAIL) is currently being tested in clinical trials; however the resistance of many tumors, including NSCLC and HCC, to TRAIL represent obstacles to its clinical application.
[0007] miRNAs are small non-coding RNAs of 19-25 nt that can block mRNA translation and/or negatively regulate its stability. At this time, over 500 different miRNAs have been identified in human cells and evidence indicates that regulation of miRNA levels is associated with growth and differentiation of many cell types and tissues. Dysregulated miRNA expression has been associated with solid and hematopoietic malignancies, and there is evidence that some miRNAs may function as oncogenes or tumor suppressor genes. miR-221 and miR-222 are among the most deregulated miRNAs implicated in cancer. Their expression is highly upregulated in a variety of solid tumors, including thyroid cancer, hepatocarcinoma and melanoma cells. Elevated miR-221 and miR-222 expression has been causally linked to proliferation, apoptosis, and migration of several cancer cell lines. However, the molecular mechanisms mediating miR-221 and miR-222 function in cancer generally, and in NSCLC and HCC specifically, is largely unknown prior to the present invention.
[0008] PTEN is a tumor suppressor in human cancers and a regulator of cell growth and apoptosis. Functionally, PTEN converts phosphatidylinositol-3,4,5-trisphosphate (PIP3) in the cytoplasm to phosphatidylinositol-4,5-bisphosphate (PIP2), thereby directly antagonizing the activity of PI3 kinase (PI3K). PTEN inactivation results in constitutive activation of the PI3K/AKT pathway and in subsequent increase in protein synthesis, cell cycle progression, migration and survival. In addition, various studies have demonstrated that the protein phosphatase activity of PTEN inhibits activation of mitogen-activated protein kinase (MAPK) via several pathways. PTEN is associated with the development of multiple drug resistance, including that to TRAIL. Constitutive activation of AKT contributes to cell migration and invasion in different types of tumors, including lung and liver carcinoma.
[0009] TIMP3 is a member of a group of proteins called matrix metalloproteinases (MMPs). MMPs are a family of zinc proteases involved in the breakdown of extracellular matrix (ECM) in normal physiological processes, such as embryonic development, tissue and bone remodeling, wound healing, and angiogenesis. Within the extracellular matrix, the tissue inhibitors of metalloproteinases (TIMPs), of which there are four family members (TIMP1 through 4), inhibit the activity of MMPs by binding with a 1:1 stoichiometry to the active site. Over-expression of TIMP3 in vascular smooth muscle cells and melanoma cell lines inhibits invasion and promotes apoptotic cell death. TIMP3, has been reported to induce the activation of both initiator caspases-8 and -9. TIMP3 has been associated with angiogenesis and tumor formation.
[0010] MET, also known as c-Met, is a membrane receptor for the hepatocyte growth factor (HGF)/scatter factor (SF). MET is normally expressed by cells of epithelial origin, while expression of HGF is restricted to cells of mesenchymal origin. Upon HGF stimulation, MET stimulates the invasive growth of cancer cells and increases their metastatic potential, principally through increased phosphorylation of ERK½ and JNK.
[0011] Phosphorylated JNKs activate the oncoprotein, c-Jun, which is known to form the activator protein-1 (AP-1) transcription factor as a homodimer or heterodimer with its partner c-Fos. Aberrant expression of HGF/SF and its receptor, MET, often correlates with poor prognosis in a variety of human malignancies. Due to their specific toxicity for malignant cells, recombinant forms of TRAIL are apoptosis-based anti-tumor agents. However, many human cancer cells remain resistant to TRAIL-induced apoptosis, but the mechanism of such resistance is not clear.
SUMMARY OF THE INVENTION
[0012] The present invention provides methods to alter the TRAIL Expression Pattern in a cell, comprising inhibiting c-Jun, miR-221 and miR-222, PTEN or TIMP3 in a cell capable of expressing c-Jun, miR-221 and miR-222, PTEN and TIMP3, and observing a TRAIL Expression Pattern alteration.
[0013] Also provided are methods to alter the TRAIL Expression Pattern in a cell, comprising overexpressing c-Jun, miR-221 and miR-222, PTEN or TIMP3 in a cell capable of expressing c-Jun, miR-221 and miR-222, PTEN and TIMP3, and observing a TRAIL Expression Pattern alteration.
[0014] Also provided are methods to identify the TRAIL Expression Pattern in a cell sample, comprising identifying expression levels of at least two nucleic acids in a cell sample, wherein the at least two are selected from the group consisting of: miR-221 and miR-222 and c-Jun; miR-221 and miR-222 and PTEN; miR-221, miR-222 and TIMP3; miR-221 and miR-222, c-Jun and PTEN; miR-221 and miR-222, PTEN and TIMP3; and miR-221 and miR-222, c-Jun and TIMP3.
[0015] Also provided are methods to alter gene expression in a TRAIL resistant cell, comprising inhibiting miR-221 and miR-222 in a cell that also expresses at least one nucleic acid selected from the group consisting of: c-Jun; PTEN and TIMP3.
[0016] Also provided are methods to alter gene expression in a TRAIL resistant cell, comprising over-expressing miR-221 and miR-222 in a cell that also expresses at least one nucleic acid selected from the group consisting of: c-Jun; PTEN and TIMP3.
[0017] Also provided are methods to identify test cells having nucleic acid expression inhibition, comprising contacting at least one test cell with antisense miR-221 and miR-222 and observing an increase in expression of a nucleic acid selected from the group consisting of: PTEN and TIMP3.
[0018] Also provided are methods of predicting the clinical outcome of a patient diagnosed with cancer, comprising detecting the expression level of miR-221 and miR-222 and at least one nucleic expression level of a nucleic acid selected from the group consisting of: c-Jun; PTEN and TIMP3, in a cancer cell sample obtained from the patient, wherein a 1.5-fold or greater increase in the level of miR-221 and miR-222 in combination with a 1.5-fold or greater decrease in the level of PTEN or TIMP3 expression in the tumor sample relative to a control predicts a decrease in survival, or wherein a 1.5-fold or greater increase in the level of miR-221 and miR-222 in combination with a 1.5-fold or greater increase in the level of c-Jun expression in the tumor sample relative to a control predicts a decrease in survival.
[0019] Furthermore, the present invention also provides methods to inhibit down-regulation of PTEN expression in a tumor cell that expresses miR-221 and miR-222 and PTEN, comprising inhibiting miR-221 and miR-222 activity in a tumor cell that expresses miR-221 and miR-222 and PTEN and observing PTEN down-regulation inhibition. Preferred are methods as described, wherein said miR-221 and miR-222 activity is inhibited via antisense miR-221 and miR-222, although those wherein PTEN expression down-regulation inhibition is observed via TRAIL sensitivity are also preferred, as are methods wherein PTEN expression down-regulation inhibition is observed via PTEN transcription analysis.
[0020] In other embodiments, there are provided methods to identify a therapeutic agent for the treatment of TRAIL-resistant cancer, comprising screening candidate agents in vitro to select an agent that decreases expression of miR-221 and miR-222 and increases expression of PTEN in a TRAIL-resistant cancer cell, thereby identifying an agent for the treatment of TRAIL-resistance cancer.
[0021] Also provided are methods of treating a mammal having TRAIL-resistant tumor cells, comprising administering to mammal having TRAIL-resistant tumor cells as identified by a 1.5-fold or greater increase in the level of miR-221 and miR-222 in combination with a 1.5-fold or greater decrease in the level of PTEN expression, a therapeutic agent capable of inhibiting down-regulation of PTEN expression.
[0022] Also provided are kits for identifying miR-221 and miR-222 up-regulation of PTEN in test cells, comprising at least one molecular identifier of miR-221 and miR-222 and at least one molecular identifier of PTEN, wherein said molecular identifier is selected from the group consisting of: probes; primers; antibodies; or small molecule.
[0023] In any of the methods herein, the preferred method utilizes cells selected from the group consisting of: cancer cell; TRAIL-resistant cancer cell; non-small cell lung carcinoma; and HCC.
[0024] In yet another aspect of the present invention, there are provided methods to alter regulation of TIMP3 expression in a cell capable of expressing TIMP3 and miR-221 and miR-222, comprising altering miR-221 and miR-222 activity in a TIMP3-expressing and miR-221 and miR-222-expressing cell and observing TIMP3 expression alteration.
[0025] Also provided are methods to inhibit TIMP3 expression in a cell capable of expressing TIMP3, comprising over-expressing miR-221 and miR-222 in a cell that also expresses TIMP3 and observing TIMP3 expression inhibition.
[0026] Also provided are methods to identify cells having TIMP3 expression inhibition, comprising contacting a test cell with antisense miR-221& miR-222 and observing an increase in TIMP3 expression.
[0027] Also provided are methods to identify TRAIL-resistant cells, comprising identifying whether a test cell sample comprises miR-221 and miR-222 nucleic acid and TIMP3 nucleic acid.
[0028] Also provided are methods to identify a therapeutic agent for the treatment of TRAIL-resistant cancer, comprising screening candidate agents in vitro to select an agent that decreases expression of miR-221 and miR-222 and increases expression of TIMP3 in a TRAIL-resistant cancer cell, thereby identifying an agent for the treatment of TRAIL-resistance cancer.
[0029] Also provided are methods of predicting the clinical outcome of a patient diagnosed with cancer, comprising detecting the level of miR-221, miR-222 and TIMP3 expression in a cancer cell sample obtained from the patient, wherein a 1.5-fold or greater increase in the level of miR-221 and miR-222 in combination with a 1.5-fold or greater decrease in the level of TIMP3 expression in the tumor sample relative to a control predicts a decrease in survival.
[0030] Also provided are methods of treating a mammal with TRAIL-resistant tumor cells, comprising administering to mammal having TRAIL-resistant tumor cells as identified by a 1.5-fold or greater increase in the level of miR-221 and miR-222 in combination with a 1.5-fold or greater decrease in the level of TIMP3 expression, a therapeutic agent capable of inhibiting down-regulation of TIMP3 expression.
[0031] Also provided are kits for identifying miR-221& miR-222 upregulation of TIMP3 in test cells, comprising at least one molecular identifier of miR-221 and miR-222 and at least one molecular identifier of TIMP3, wherein said molecular identifier is selected from the group consisting of: probes; primers; antibodies; or small molecule.
[0032] Also provided are methods preferred methods, wherein said cell is selected from the group consisting of: cancer cell; TRAIL-resistant cancer cell; non-small cell lung carcinoma; and hepatocarcinoma.
[0033] Also provided are methods to inhibit down-regulation of TIMP3 expression in a tumor cell that expresses miR-221, miR-222 and TIMP3, comprising inhibiting miR-221 and miR-222 activity in a tumor cell that expresses miR-221, miR-222 and TIMP3 and observing TIMP3 down-regulation inhibition. Preferred are those methods as described, wherein said miR-221 and miR-222 activity is inhibited via antisense miR-221 and miR-222, or wherein TIMP3 expression down-regulation inhibition is observed via TRAIL sensitivity, or wherein TIMP3 expression down-regulation inhibition is observed via TIMP3 translation analysis.
[0034] The foregoing and other features and advantages of the disclosure will become more apparent from the following detailed description of several embodiments which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE FIGURES
[0035] The patent or application file may contain one or more drawings executed in color and/or one or more photographs. Copies of this patent or patent application publication with color drawing(s) and/or photograph(s) will be provided by the Patent Office upon request and payment of the necessary fee.
[0036] FIGS. 1A-1H . PTEN and TIMP3 are targets of miR-221 and miR-222:
[0037] FIG. 1A . PTEN and TIMP3 3′UTRs contain one predicted miR-221 and miR-222 binding site. In FIG. 1A is shown the alignment of the seed regions of miR-221 & 222 with PTEN and TIMP3 3′UTRs. The sites of target mutagenesis are indicated in red. ( FIG. 1A discloses SEQ ID NOS 26-29, and 26, 30, 28, and 31, respectively, in order of appearance.)
[0038] FIG. 1B . qRT-PCR in MEGO1 cells after enforced expression of miR-221 and miR-222.
[0039] FIG. 1C . PTEN and TIMP3 3′ UTRs are targets of miR-221 and miR-222. pGL3-PTEN and pGL3-TIMP3 luciferase constructs, containing a wild type (left side of the histograms) or mutated (right side of the histograms) PTEN and TIMP3 3′ UTRs, were transfected into MEGO1 cells. Relative repression of firefly luciferase expression was standardized to a transfection control. The reporter assays were performed three times with essentially identical results.
[0040] FIG. 1D . qRT-PCR in H460 cells after enforced expression of miR-221 and miR-222.
[0041] FIG. 1E . miR-221 and miR-222 enforced expression decreases endogenous levels of PTEN and TIMP3 proteins in H460 NSCLC. H460 cells were transfected with either scrambled or miR-221 or miR-222 for 72 h. PTEN and TIMP3 expression was assessed by western blot. Loading control was obtained by using anti-β-actin antibody.
[0042] FIG. 1F . qRT-PCR showing miR-221 and miR-222 downmodulation in Calu-1 cells after anti-miRs transfection.
[0043] FIG. 1G . Western blot showing PTEN and TIMP3 expression after miR-221 and miR-222 downregulation by using anti-miR-221 and miR-222. Anti-miR-221 and -222 were able to increase PTEN and TIMP3 expression in Calu-1 cell line.
[0044] FIG. 1H . qRT-PCR of PTEN and TIMP3 mRNA after miR-221 and miR-222 forced expression in H460 cells. PTEN but not TIMP3 mRNA was downregulated by miR-221 and miR-222. Data are presented as SD.
[0045] FIGS. 2A-2B . PTEN and TIMP3 expression is inversely related to that of miR-221 and miR-222 in NSCLC and HCC.
[0046] FIG. 2A . miR-221 and -222 expression levels was assessed by northern blot analysis using 154 of total RNA for NSCLC and 10 μg of total RNA for HCC cells. Western Blots anti-PTEN and TIMP3 were performed using total proteins extract (50 μg) isolated from the different NSCLC and HCC.
[0047] FIG. 2B . qRT-PCR of miR-221 and miR-222 and PTEN mRNA was performed by extracting RNA from the different NSCLC and HCC as described in the “Supplemental Experimental Procedures” section. miR-221 and miR-222 were inversely related to PTEN mRNA expression in all the different NSCLC and HCC cells. Data are presented as SD.
[0048] FIGS. 3A-3C . PTEN and TIMP3 are direct targets of miR-221 and miR-222 in HCC in vitro and in vivo.
[0049] FIG. 3A . Western blot showing PTEN and TIMP3 expression in Sk-Hep1 and Snu-387 cells after miR-221 and miR-222 overexpression or downregulation. miR-221 and miR-222 were able to downregulate PTEN and TIMP3 expression in Sk-Hep1; conversely, anti-miR-221 and miR-222 were able to increase PTEN and TIMP3 expression in Snu-387 cells.
[0050] FIG. 3B . qRT-PCR on 22 lung cancer patients and 10 normal lung tissues. The association between miR-221/miR-222 and PTEN mRNA for the 10 subjects in the normal class and for the 22 subjects in the tumor class was calculated statistically by using the Pearson Correlation Coefficient (r) and the respective p-value, all significant at p0.05. The Pearson correlation indicated an inverse relation between miR-221,-222 and PTEN mRNA in the normal and tumor samples.
[0051] FIG. 3C . IHC and ISH on hepatocarcinoma and normal liver tissues samples. miR-221/miR-222 (blue) and PTEN/TIMP3 (red) expression were inversely related in liver cancers and the adjacent normal/cirrhotic liver tissues. These tissues were analyzed for miR-221 and miR-222 expression by in situ hybridization, followed by immunohistochemistry for PTEN and TIMP3. Liver cancer cells abundantly expressed miR-221/miR-222 and rarely expressed PTEN or TIMP3 (labeled as G, H, K, L) whereas the adjacent non-malignant liver abundantly expressed PTEN or TIMP3 and rarely had detectable miR-221/miR-222 (labeled as A, B, E, F). In the cases of hepatocellular carcinoma where both miR-221/miR-222 and TIMP3 expression were noted, the cancer cells expressing miR-221 (large arrow, labeled as K; TIMP3 is depicted by arrow in labeled as L) were distinct from those cells expressing TIMP3 (labeled as K, small arrow). Labeled as C-I, H & E; D-J miR-302, which is not express in liver, was used as negative control. 80 human HCC were analyzed. Scale bars indicate 25 m.
[0052] FIGS. 4A-4E . miR-221 and miR-222 induce TRAIL-resistance in NSCLC and HCC by targeting PTEN and TIMP3.
[0053] FIG. 4A . Proliferation assay on five different HCC. Cells were incubated with Super-Killer-TRAIL (400 ng/ml) for 24 h and viability evaluated as described in the supplemental methods. Huh7, HepG2 and Sk-Hep1 with low miR-221 and -222 expression, were more sensitive to TRAIL-induced apoptosis compared to PLC/PLF-5 and Snu-387, highly expressing miR-221/miR-222. Mean SD of four independent experiments repeated in triplicate.
[0054] FIG. 4B . Cell death effects in Sk-Hep1 cells after miR-221/miR-222 forced expression and PTEN or TIMP3 downregulation. Cells were transfected either with control miR or with pre-miR-221-222. 24 h after transfection, cells were treated with Super-Killer TRAIL for 24 hours. Apoptosis was evaluated either with Annexin-FITC or ( FIG. 4C ) with caspase-Glo 3/7 kit. TRAIL resistance increased after miR-221/miR-222 overexpression or PTEN and TIMP3 downmodulation.
[0055] FIG. 4D . Effects of miR-221/miR-222 on cell death. H460 cells were transfected either with control siRNA or control miR or with 100 nmol of PTEN and TIMP3 siRNA. After 48 h from the transfection cells were treated with Super-Killer TRAIL for 24 hours. Apoptosis was evaluated by caspase 3/7 activity or FIG. 4E ) Annexin-V. Percentage of apoptotic cells decreased after PTEN and TIMP3 downregulation. Error bars indicate SD. *p<0.05, **p<0.001 by t test.
[0056] FIGS. 5A-5G . Anti-miR-221 and miR-222 override TRAIL-resistance in NSCLC and HCC through the inhibition of the AKT pathway.
[0057] ( FIGS. 5A-5C ) Western Blots in H460 cells after miR-221/miR-222 forced expression. miR-221 and miR-222 forced expression induces the activation of the AKT/ERKs pathways and Metallopeptidases.
[0058] FIG. 5B . Western blots in Snu-387 cells after miR-221 and miR-222 knockdown by anti-miR-221/miR-222. The inhibition of the AKT pathway is showed as result of miR-221 and miR-222 downregulation.
[0059] FIGS. 5D-5E . Western blots after PTEN or TIMP3 knockdown. Erks phosphorylation and PAK1 activation are both PTEN and TIMP3 dependent. The activation of the AKT pathway is PTEN-dependent, while TIMP3 silencing induces the expression of metallopeptidases.
[0060] FIG. 5F-5G . Effects of anti-miRs and AKT pathway inhibition by API2/triciribine on cell death. Calu-1 and Snu-387 cells were transfected with anti-miR221/miR-222 for 72 h, or treated with API2/triciribine for 48 h. miR-221 and miR-222 downmodulation and/or the inhibition of the Akt pathway, induced an increase in apoptosis percentage in both Calu-1 and Snu-387 cell lines, as assessed by caspase 3/7 activity. Error bars indicate SD. **p<0.001 by t test.
[0061] FIGS. 6A-6D . Ectopic expression of miR-221 and miR-222 affects the cell cycle distribution and migration/invasion capabilities of H460 cells.
[0062] FIG. 6A . Flow cytometric distributions of H460 cells transfected with pre-miR scrambled, miR-221 and miR-222, siRNA scrambled, siRNA PTEN. H460 transfected cells showed a decrease of G1 and a corresponding increase of the S and G2-M phases, as a consequence of PTEN downregulation.
[0063] FIGS. 6B-6C . miR-221 and miR-222 regulate cell migration ability in H460 cells. Migration Assay was performed as described in the “Experimental Procedures”.
[0064] FIG. 6D . miR-221 and miR-222 influences H460 and Sk-Hep1 cell invasion ability. Histogram reports the percentage of cells that invaded through Matrigel-coated membrane after transfection with negative control miRNA, miR-221, miR-222, siPTEN and siTIMP3. One-way analysis of variance (ANOVA) was performed to test the differences among means of invasion values. The Scheffe′ multiple-comparison method was used to test the differences between each pair of means. Significant differences were found between the scrambled vs miR-221 and miR-222, PTEN and TIMP3 H460 transfected cells (p-value 0.001). The same results were obtained using the Bonferroni and Sidak methods. Error bars indicate SD. *p<0.001 by t test. Scale bar indicates 25 m. The magnification is the same for all the panels.
[0065] FIGS. 7A-7K . MET oncogene regulates miR-221 and miR-222 activation.
[0066] (FIGS. 7 A- 7 B- 7 C. Relative expression levels of miR-221 and miR-222 in Calu-1, Snu-387 and GTL16 after transfection with miR control and siRNA MET. miR-221 and miR-222 expression decreased after MET knockdown.
[0067] FIGS. 7 D- 7 E- 7 F. Western blots after siRNA MET transfection in Calu-1, Snu-387 and GTL16 cells. MET knockdown decreased miR-221 and miR-222 expression levels, giving rise to PTEN and TIMP3 upregulation in all the different cell lines. GTL16 cells were moreover treated for 24 h with 4 μM of the MET inhibitor SU11274. MET inhibition increased miR-221 and miR-222 targets expression levels.
[0068] FIGS. 7 G- 7 H- 7 I. Identification of c-Jun (AP-1) interacting region by using 2 different amplicons across the miR-221/miR-222 transcription start site. ChIP analysis was performed with chromatin from H460 c-Jun negative cells, Calu-1 and Snu-387 c-Jun positive cells. BS=binding site.
[0069] FIG. 7J . qRT-PCR of miR-221 and miR-222 in Huh7 cells after treatment with anisomycin (10 M) for 30 min Anisomycin induced miR-221 and miR-222 upregulation.
[0070] FIG. 7K . Anisomycin induced c-Jun activation and PTEN and TIMP3 downregulation in Huh7 cells. Total lysate was analyzed by western blot using anti-PTEN and anti-TIMP3 antibody. Error bars indicate SD.
[0071] FIG. 8 . MET induces miR-221 and miR-222 activation through AP-1 (c-Jun) transcription factor. A model is reported in which growth factors determine c-Met activation which, in turn, through AP-1 and accordingly miR-221 and miR-222 upregulation, gives rise to PTEN and TIMP3 downregulation and subsequent apoptosis resistance, cellular migration and invasion.
[0072] FIGS. 9A-9L . IHC and ISH of miR-221/miR-222 and PTEN/TIMP3 in lung cancers and the adjacent benign tissues. miR-221/miR-222 (blue) and PTEN/TIMP3 (red) expression were inversely related in lung cancers and the adjacent normal lung tissues. These tissues were analyzed for miR-221 and miR-222 expression by in situ hybridization, followed by immunohistochemistry for PTEN and TIMP3 as described in the “Supplemental Experimental Procedures”. The majority of cancer cells were positive for miR-221 and miR-222 and negative for PTEN ( FIGS. 9F-9G ) and TIMP3 ( FIGS. 9I-9J ). Conversely, the normal cells were negative for miR-221/miR-222 (FIGS. 9 A- 9 B- 9 D- 9 E) and positive for PTEN and TIMP3. Note that in several cancers ( FIGS. 9I and 9J ) miR-221/miR-222 expression was evident with TIMP3 expression; however the miRNA expression was evident in the cancer cells and the TIMP3 expression in the surrounding cells in the desmoplastic tissue.
[0073] FIGS. 9C-9H . H&E—Small arrow miR-221-222, big arrow TIMP3. 92 human lung carcinomas were analyzed.
[0074] FIGS. 9K-9L . Correlation of miRNA-221/miR-222 expression and histology in the lung. miR-221 and -222 showed equivalent distribution patterns in this squamous cell carcinoma of the lung. FIG. 9K shows a strong signal (large arrow) in the nests of tumor cells that are infiltrating the adjacent fibrotic lung tissue. Note that the signal shows a cytoplasmic and nuclear membrane based localization in the cancer cells ( FIG. 9L , higher magnification). In comparison, only rare benign cells express miR-222 in the adjacent fibrotic tissue (small arrow) which is being invaded by the cancer cells. Scale bars indicate 25 m.
[0075] FIGS. 10A-10B . Caspase 3/7 activity in HepG2 and Huh7 cells after miR-221 and miR-222 upregulation or PTEN/TIMP3 knockdown. For caspase 3/7 activity detection, cells were cultured in 96-well plates, transfected with 100 nM miR-221 and miR-222 for 72 h. After 48 h from transfection cells were treated with TRAIL 400ng/m1 for 24 h and analyzed using Caspase-Glo 3/7 Assay kit according to the manufacturer's instructions. HepG2 and Huh7 cells became resistant to TRAIL inducing apoptosis after miR-221 and miR-222 forced expression or PTEN/TIMP3 downregulation. Data are presented as ±SD.
[0076] FIGS. 11A-11C . TIMP3 overexpression induces apoptosis in Calu-1 TRAIL resistant cells.
[0077] FIG. 11A . Caspase 3/7 activity in Calu-1 cells after PTEN, TIMP3 and PTEN/TIMP3 upregulation. Cells were cultured in 96-well plates, transfected with PTEN, TIMP3 or both for 72 h. After 48 h from transfection cells were treated with TRAIL 400 ng/ml for 24 h and analyzed using Caspase-Glo 3/7 Assay kit according to the manufacturer's instructions. Calu-1 cells became sensitive to TRAIL-inducing apoptosis after PTEN, TIMP3 or both PTEN/TIMP3 overexpression.
[0078] FIG. 11B . Effects of PTEN and TIMP3 on cell death. Calu-1 cells were transfected either with PTEN and TIMP3 plasmids. After 48 h from the transfection cells were treated with 400 ng/ml of Super-Killer TRAIL for 24 hours. Apoptosis was evaluated by Annexin-V. Percentage of apoptotic cells increases after PTEN and TIMP3 upregulation.
[0079] FIG. 11C . Western Blots in Calu-1 cells after TIMP3 overexpression. Fifty micrograms of total extract was loaded onto SDS-PAGE polyacrylamide gels and membranes were blotted with the indicated antibodies. TIMP3 overexpression activates both the extrinsic and intrinsic apoptotic pathways. Error bars indicate SD. *p<0.001 by t test.
[0080] FIGS. 12A-12G . Effects of PTEN and TIMP3 silencing on tumorigenicity of H460 cells in vivo.
[0081] FIGS. 12A-12B . Western blots showing PTEN and TIMP3 expression in H460 xenografts after shPTEN and shTIMP3 stable transfection. 35 days from the injection mice were sacrificed and tumors were analyzed by western blot.
[0082] FIGS. 12C-12D . Comparison of tumor engraftment sizes of sh control, shPTEN and shTIMP3 in H460 cells 35 days from the injection in nude mice and after treatment with vehicle (PBS) or TRAIL. PTEN and TIMP3 knockdown increases TRAIL resistance in vivo. The images show average-sized tumors from among five of each category.
[0083] FIGS. 12 E- 12 F- 12 G. Growth curve of engrafted tumors in nude mice injected with H460 cells stable transfected with sh control, sh PTEN and shTIMP3. Data are presented as SD. *p 0.001.
[0084] FIGS. 13A-13B . Ectopic expression of miR-221 and miR-222 affects the cell cycle distribution and migration/invasion capabilities of Sk-Hep1 cells.
[0085] FIG. 13A . Flow cytometric distributions of Sk-Hep1 cells transfected with empty vector, miR-221 and miR-222, siRNA PTEN. The average of three independent experiments is reported.
[0086] FIG. 13B . miR-221 and miR-222 regulate cell migration ability in Sk-Hep1 cells. Transwell insert chambers with 8-nm porous membrane were used for the assay. After transfection cells were washed with PBS and 150,000 cells were added to the top chamber in serum-free media. The bottom chamber was filled with media containing 10% FBS. To quantify migrating cells, cells on the top chamber were removed by using a cotton-tipped swab, and the migrated cells were fixed in PBS, 25% glutaraldehyde and stained with Crystal Violet stain. Four random fields were counted. Scale bar indicates 25 m. The magnification is the same for all the panels.
[0087] FIGS. 14A-14B . 2′-O-me-anti-mR-221 and miR-222 reduce cell migration and invasion ability of Calu-1 and Snu-387 cells.
[0088] FIG. 14A . Transwell insert chambers with 8 μm porous membrane were used for the assay. After transfection cells were washed with PBS and 50,000 cells were added to the top chamber in serum-free media. The bottom chamber was filled with media containing 10% FBS. To quantify migrating cells, cells on the top chamber were removed by using a cotton-tipped swab, and the migrated cells were fixed in PBS, 25% glutaraldehyde and stained with Crystal Violet stain. Five random fields were counted. miR-221 and miR-222 knockdown reduce Calu-1 and Snu-387 cells migration.
[0089] FIG. 14B . miR-221 and miR-222 influence Calu-1 and Snu-387 cell invasion ability. Histogram reports the percentage of cells that invaded through Matrigel-coated membrane after transfection with negative control miRNA, anti-miR-221, or anti-miR-222. Data are presented as ±SD of 3 separate determinations. Scale bars indicate 25 m.
[0090] FIGS. 15A-15F . c-Jun binds to miR-221/miR-222 promoter determining its activation.
[0091] FIG. 15A . qRT-PCR in GTL-16 cells after MET inhibition by using the MET inhibitor SU11274. miR-221 and miR-222 were downregulated of about 40%, as compared with the untreated cells.
[0092] FIG. 15B . c-Jun and c Fos expression levels in four different cell lines. 50 μg of total lysates were loaded onto a 12% polyacrylamide gel. Calu-1 and Snu-387 showed high c-Jun expression, Huh7 low expression levels and in H460 c-Jun expression was absent. c-Fos expression level is very high in Calu-1 cells, lower in all the other cell lines.
[0093] FIG. 15C . qRT-PCR on Calu-1 cells after MET, c-Jun, and c-Fos downregulation. Total 5ng of RNA in 10 μl PCR was used. TaqMan ACT values were converted into absolute copy numbers using a standard curve from synthetic lin-4 miRNA. Data are expressed as the relative expression of the different miRs, compared to U44 and U48 rRNA. miR-221 and miR-222 are downregulated after MET and c-Jun but not c-Fos knockdown by siRNAs, demonstrating that c-Jun is the transcription factor responsible for miR-221 and miR-222 activation.
[0094] FIGS. 15D-15E . Luciferase assays in Calu-1 cells after cotransfection with reporter plasmid harboring different sites of miR-221 and miR-222 promoter (−150,−600,−1000) and siRNA MET, siRNA c-Jun, siRNA c-Fos. MET and c-Jun siRNAs but not c-Fos siRNA, were able to decrease miR-221 and miR-222 luciferase activity.
[0095] FIG. 15F . Western blots after c-Met and c-Jun silencing. MET knockdown reduces JNK½ phosphorylation. c-Jun silencing gives rise to an increased expression of PTEN and TIMP3. Data are presented as ±SD.
[0096] FIGS. 16A-16H . PTEN, TIMP3 and MET co-labeling. IHC and ISH were performed on 72 lung tumor samples.
[0097] FIG. 16A . IHC of c-Met alone (brown).
[0098] FIG. 16B . TIMP3 alone (red).
[0099] FIG. 16C . c-Met/TIMP3 colabeling in lung cancers.
[0100] FIG. 16D . Nuclei as demonstrated by a hematoxylin counterstain. c-Met is expressed only in the cancer cells (big arrows) whereas TIMP3 is expressed in the surrounding benign cells (small arrows). Note that when c-MET is present TIMP3 is absent and vice versa.
[0101] FIG. 16E . Colocalization of c-Met (red) and TIMP3 (brown) in hepatocellular carcinoma (60 tumor samples were analyzed). Note that the tumor cells express c-Met and that TIMP3 expression is not evident. The panel also shows the hematoxylin stained features of the cancer, marked by multiple invasive nests in a desmoplastic stroma.
[0102] FIG. 16F . The same field analyzed by the Nuance system, with fluorescent red representing c-Met, fluorescent yellow representing TIMP3, and fluorescent green cells co-labeled with c-Met and TIMP3. As evident, no cancer cells co-label with c-Met and TIMP3.
[0103] FIG. 16G . Colocalization of c-Met and PTEN in lung carcinoma. The c-Met stain (red) shows the cell membrane pattern typical for c-Met in the cancer cells (large arrows). Adjacent to them is the stroma, with its benign fibroblasts and macrophages that express PTEN (brown—small arrow) but not cMET.
[0104] FIG. 16H . H&E—Scale bar indicates 25 m. The magnification is the same for all the panels.
[0105] FIGS. 17A-17E . MET silencing reduces cell migration and invasion in Calu-1 and Snu-387 cells and enhances TRAIL sensitivity in vivo.
[0106] FIG. 17A . Transwell insert chambers with 8-nm porous membrane were used for migration assay. After transfection cells were washed with PBS and 50.000 cells were added to the top chamber in serum-free media. The bottom chamber was filled with media containing 10% FBS. To quantify migrating cells, cells on the top chamber were removed by using a cotton-tipped swab, and the migrated cells were fixed in PBS, 25% glutaraldehyde and stained with Crystal Violet stain. Five random fields were counted.
[0107] FIG. 17B . MET influences Calu-1 and Snu-387 cell invasion ability. Histogram reports the percentage of cells that invaded through Matrigel-coated membrane after transfection with siRNA negative control or siRNA MET. Data are expressed as mean±standard error of 3 separate determinations.
[0108] FIG. 17C . Western blots showing MET expression in Calu-1 xenografts after shMET stable transfection. 35 days from the injection mice were sacrificed and tumors were analyzed by western blot.
[0109] FIGS. 17D-17E . Growth curve of engrafted tumors in nude mice injected with Calu-1 cells stable transfected with sh control and shMET. Data are presented as SD. *p 0.01. Scale bar indicates 25 m. The magnification is the same for all the panels.
SEQUENCE LISTING
[0110] The instant application contains a Sequence Listing which has been submitted via EFS-web and is hereby incorporated by reference in its entirety. The ASCII copy, created on Nov. 22, 2010, is named 604 — 51413_SEQLIST_OSU-10076.txt, and is 7,374 bytes in size.
[0111] The nucleic and amino acid sequences listed in the accompanying sequence listing are shown using standard letter abbreviations for nucleotide bases, and three letter code for amino acids, as defined in 37 C.F.R. 1.822. Only one strand of each nucleic acid sequence is shown, but the complementary strand is understood as included by any reference to the displayed strand.
DETAILED DESCRIPTION
[0112] The present invention provides that the activation of miR-221 and miR-222 is regulated, at least in part, by the MET oncogene and the c-Jun transcription factor, and which, in turn, down-regulates PTEN and TIMP3.
[0113] Activation of MET signaling is a frequent genetic event observed in liver and lung cancer development. AP-1 is a complex of dimeric basic region-leucine zipper proteins that belong to the Jun (c-Jun, JunB, JunD), Fos (c-Fos, FosB, Fra-1 and Fra-2), Maf and ATF subfamilies c-Jun is the most potent transcriptional activator in its group, whose transcriptional activity is attenuated and sometimes antagonized by JunB. The Fos proteins, which cannot homodimerize, form stable heterodimers with Jun proteins and thereby enhance their DNA binding activity.
[0114] The present inventors focused on these two AP-1 subfamilies, and in particular on c-Jun and c-Fos, although they found by bioinformatics search (TESS database) that also ATF-1 and JunD, could be potential transcription factors involved in miR-221 and miR-222 activation. The present invention demonstrates that c-Jun and not c-Fos is involved in miR-221 and miR-222 activation and that c-Jun has one binding site in the miR-221/miR-222 promoter region. The induction of AP-1 is mostly mediated by the JNK cascades.
[0115] By using anisomycin, an antibiotic which activates the JNK cascade, the inventors found an increase of miR-221/miR-222 expression in Huh7 hepatocarcinoma cells, as consequence of c-Jun phosphorylation. Intriguingly, when the inventors grew Huh7 cells in serum free medium, they did not observe any variation in the expression level of miR-221 and miR-222 or PTEN and TIMP3, showing that MET activation is important for miR-221 and miR-222 transcription regulation and subsequent cellular migration.
[0116] To address this issue the inventors investigated Calu-1 and Snu-387 cell migration and invasion after MET silencing. Migratory and invasive capabilities of both cell lines were reduced after MET oncogene silencing ( FIGS. 17A-17B ).
[0117] Furthermore, a xenograft model of Calu-1 cells in which c-Met was silenced by using an shMET plasmid ( FIG. 17C ), showed that mice injected with Calu-1 shMET cells are more sensitive to TRAIL inducing apoptosis compared to the mice injected with the sh control ( FIGS. 17D-17E ). Thus MET confers not only a tumor growth advantage but also resistance to TRAIL-inducing apoptosis over control tumors in vivo. Therefore, MET oncogene regulates miR-221 and miR-222 levels and, accordingly, cellular invasion and migration through c-Jun transcription factor and JNK activation ( FIG. 8 ).
[0118] Taken together, these data highlight a mechanism, involving MET, through which miR-221 and miR-222 promote tumorigenesis and metastasis. Thus approaches targeting MET receptor and/or miR-221 and miR-222 in order to sensitize NSCLC and HCC to TRAIL-inducing apoptosis, but also in the prevention and inhibition of lung cancer and hepatocellular carcinoma, are included in the present invention.
[0119] In the present invention, there are identified major mRNA targets and signaling pathways that mediate miR-221 and miR-222 regulation in a wide panel of NSCLC and HCC-derived cell lines. In vitro and in vivo experiments reveal that elevated levels of miR-221 and miR-222 in NSCLCs and HCCs correlates with PTEN and TIMP3 down-regulation, indicating that these two microRNAs are a causal factor in the down-regulation of PTEN and TIMP3 in these types of cancers.
[0120] The inventors examined the effects of miR-221 and miR-222 and their targets on cell survival and TRAIL resistance. Interestingly, the inventors found that after miR-221/miR-222 enforced expression, or PTEN and TIMP3 down regulation, TRAIL-sensitive NSCLC and HCC cells became resistant to TRAIL-inducing apoptosis, although PTEN down regulation was slightly more effective than that of TIMP3.
[0121] The present invention provides methods to affect miR-221 and miR222 expression, since it is now proved that miR-221 and miR-222 expression is a “prerequisite” of TRAIL-resistant NSCLC and HCC cells. Importantly, tumor stratification, on the basis of miR-221/miR-222 expression levels, could be used as prognostic tool to predict TRAIL-sensitivity or TRAIL-resistance in the treatment of NSCLCs and HCCs.
[0122] The present invention also discloses that miR-221 and miR-222 block PTEN expression leading to activation of the AKT pathway, showing that miR-221 and miR-222 plays an important role in cell growth and invasiveness by targeting the PTEN/AKT pathway. In this regard, cell cycle analysis evidenced an increase in cell growth tightly linked to the G1 to S shift, which is in agreement with modulation of PTEN and also of p27kip1, a known regulator of the G1/S cell cycle checkpoint and a downstream effector of PTEN.
[0123] NSCLC and HCC cells overexpressing miR-221 and miR-222 are not only TRAIL-resistant but they also show an increase in migration and invasion capabilities, compared to cells expressing lower levels of miR-221 and miR-222 cells.
[0124] Moreover, miR-221 and miR-222 are herein shown to promote cell migration, invasion and growth via direct repression of PTEN and TIMP3 expression and of downstream pathways involving AKT and ERKs phosphorylation, and the activation of MMP-3 and MMP-9.
[0125] Further, PTEN and TIMP3 loss in H460 tumor xenograft conferred not only a significant tumor growth advantage but also a resistance to TRAIL-inducing apoptosis over control tumors also in vivo. Interestingly, the TIMP3 knockdown tumors were more vascularized than the control tumors, highlighting its role in angiogenesis and tumor formation.
[0126] The identification of miR-221 and miR-222 as important regulators of tumor cell proliferation, migration, and invasion of NSCLC and HCC, in vitro and in vivo, provides insights into the role of these miRNAs in hepatic and lung oncogenesis and tumor behavior.
[0127] The effects of miR-221 and miR-222 and their targets on cell survival and TRAIL resistance were examined Interestingly, after miR-221/miR-222 enforced expression, or PTEN and TIMP3 downregulation, TRAIL-sensitive NSCLC and HCC cells became resistant to TRAIL-inducing apoptosis, although PTEN down regulation was slightly more effective than that of TIMP3. This indicates that miR-221 and miR-222 overexpression is a “prerequisite” of TRAIL-resistant NSCLC and HCC cells.
[0128] Importantly, tumor stratification, on the basis of miR-221/miR-222 expression levels, could be used as prognostic tool to predict TRAIL-sensitivity or TRAIL-resistance in the treatment of NSCLCs and HCCs.
ABBREVIATIONS
[0000]
DNA Deoxyribonucleic acid
HCC Hepatocellular carcinoma
IL Interleukin
ISH In situ hybridization
miR MicroRNA
miRNA MicroRNA
mRNA Messenger RNA
PCR Polymerase chain reaction
pre-miRNA Precursor microRNA
qRT-PCR Quantitative reverse transcriptase polymerase chain reaction
RNA Ribonucleic acid
siRNA Small interfering RNA
snRNA Small nuclear RNA
SVM Support vector machines
[0143] Terms
[0144] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the scope of the current teachings. In this application, the use of the singular includes the plural unless specifically stated otherwise.
[0145] The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”
[0146] Also, the use of “comprise”, “contain”, and “include”, or modifications of those root words, for example but not limited to, “comprises”, “contained”, and “including”, are not intended to be limiting. The term “and/or” means that the terms before and after can be taken together or separately. For illustration purposes, but not as a limitation, “X and/or Y” can mean “X” or “Y” or “X and Y”.
[0147] It is understood that an miRNA is derived from genomic sequences or a gene. In this respect, the term “gene” is used for simplicity to refer to the genomic sequence encoding the precursor miRNA for a given miRNA. However, embodiments of the invention may involve genomic sequences of a miRNA that are involved in its expression, such as a promoter or other regulatory sequences.
[0148] The term “miRNA” generally refers to a single-stranded molecule, but in specific embodiments, molecules implemented in the invention will also encompass a region or an additional strand that is partially (between 10 and 50% complementary across length of strand), substantially (greater than 50% but less than 100% complementary across length of strand) or fully complementary to another region of the same single-stranded molecule or to another nucleic acid. Thus, nucleic acids may encompass a molecule that comprises one or more complementary or self-complementary strand(s) or “complement(s)” of a particular sequence comprising a molecule. For example, precursor miRNA may have a self-complementary region, which is up to 100% complementary miRNA probes of the invention can be or be at least 60, 65, 70, 75, 80, 85, 90, 95, or 100% complementary to their target.
[0149] The term “combinations thereof” as used herein refers to all permutations and combinations of the listed items preceding the term. For example, “A, B, C, or combinations thereof” is intended to include at least one of: A, B, C, AB, AC, BC, or ABC, and if order is important in a particular context, also BA, CA, CB, ACB, CBA, BCA, BAC, or CAB.
[0150] Unless otherwise noted, technical terms are used according to conventional usage. Definitions of common terms in molecular biology may be found in Benjamin Lewin, Genes V, published by Oxford University Press, 1994 (ISBN 0-19-854287-9); Kendrew et al. (eds.), The Encyclopedia of Molecular Biology, published by Blackwell Science Ltd., 1994 (ISBN 0-632-02182-9); and Robert A. Meyers (ed.), Molecular Biology and Biotechnology: a Comprehensive Desk Reference, published by VCH Publishers, Inc., 1995 (ISBN 1-56081-569-8).
[0151] In order to facilitate review of the various embodiments of the disclosure, the following explanations of specific terms are provided:
[0152] Adjunctive therapy: A treatment used in combination with a primary treatment to improve the effects of the primary treatment. For example, a patient diagnosed with HCC may undergo liver resection as a primary treatment and antisense miR-221 and miR-222 therapy as an adjunctive therapy.
[0153] Candidate: As used herein, a “candidate” for therapy is a patient that has TRAIL-Resistant TRAIL Expression Pattern.
[0154] Clinical outcome: Refers to the health status of a patient following treatment for a disease or disorder, such as HCC, or in the absence of treatment. Clinical outcomes include, but are not limited to, an increase in the length of time until death, a decrease in the length of time until death, an increase in the chance of survival, an increase in the risk of death, survival, disease-free survival, chronic disease, metastasis, advanced or aggressive disease, disease recurrence, death, and favorable or poor response to therapy.
[0155] Control: A “control” refers to a sample or standard used for comparison with an experimental sample, such as a tumor sample obtained from a patient having TRAIL-resistant cancer. In some embodiments, the control is a liver sample obtained from a healthy patient or a non-cancerous tissue sample obtained from a patient diagnosed with HCC. In some embodiments, the control is a historical control or standard value (i.e. a previously tested control sample or group of samples that represent baseline or normal values, such as the level Trail Expression Pattern in non-cancerous tissue).
[0156] Cytokines: Proteins produced by a wide variety of hematopoietic and non-hematopoietic cells that affect the behavior of other cells. Cytokines are important for both the innate and adaptive immune responses.
[0157] Decrease in survival: As used herein, “decrease in survival” refers to a decrease in the length of time before death of a patient, or an increase in the risk of death for the patient.
[0158] Detecting level of expression: For example, “detecting the level of miR-221 and miR-222 expression” refers to quantifying the amount of miR-221 and miR-222 present in a sample. Detecting expression of miR-221 and miR-222, or any microRNA, can be achieved using any method known in the art or described herein, such as by qRT-PCR. Detecting expression of miR-221 and miR-222 includes detecting expression of either a mature form of miR-221 and miR-222 or a precursor form that is correlated with miR-221 and miR-222 expression. Typically, miRNA detection methods involve sequence specific detection, such as by RT-PCR. miR-221 and miR-222-specific primers and probes can be designed using the precursor and mature miR-221 and miR-222 nucleic acid sequences, which are known in the art and include modifications which do not change the function of the sequences.
[0159] Hepatocellular carcinoma (HCC): HCC is a primary malignancy of the liver typically occurring in patients with inflammatory livers resulting from viral hepatitis, liver toxins or hepatic cirrhosis (often caused by alcoholism).
[0160] MicroRNA (miRNA, miR): Single-stranded RNA molecules that regulate gene expression. MicroRNAs are generally 21-23 nucleotides in length. MicroRNAs are processed from primary transcripts known as pri-miRNA to short stem-loop structures called precursor (pre)-miRNA and finally to functional, mature microRNA. Mature microRNA molecules are partially complementary to one or more messenger RNA molecules, and their primary function is to down-regulate gene expression. MicroRNAs regulate gene expression through the RNAi pathway.
[0161] miR-221 and miR-222 expression: As used herein, “low miR-221 and miR-222 expression” and “high miR-miR-221 and miR-222 expression” are relative terms that refer to the level of miR-221 and miR-222 found in a sample, such as a healthy or HCC liver sample. In some embodiments, low and high miR-221 and miR-222 expression are determined by comparison of miR-221 and miR-222 levels in a group of non-cancerous and HCC liver samples. Low and high expression can then be assigned to each sample based on whether the expression of miR-221 and miR-222 in a sample is above (high) or below (low) the average or median miR-221 and miR-222 expression level. For individual samples, high or low miR-221 and miR-222 expression can be determined by comparison of the sample to a control or reference sample known to have high or low expression, or by comparison to a standard value. Low and high miR-221 and miR-222 expression can include expression of either the precursor or mature forms or miR-221 and miR-222, or both.
[0162] Patient: As used herein, the term “patient” includes human and non-human animals. The preferred patient for treatment is a human. “Patient” and “subject” are used interchangeably herein.
[0163] Pharmaceutically acceptable vehicles: The pharmaceutically acceptable carriers (vehicles) useful in this disclosure are conventional. Remington's Pharmaceutical Sciences, by E. W. Martin, Mack Publishing Co., Easton, Pa., 15th Edition (1975), describes compositions and formulations suitable for pharmaceutical delivery of one or more therapeutic compounds, molecules or agents.
[0164] In general, the nature of the carrier will depend on the particular mode of administration being employed. For instance, parenteral formulations usually comprise injectable fluids that include pharmaceutically and physiologically acceptable fluids such as water, physiological saline, balanced salt solutions, aqueous dextrose, glycerol or the like as a vehicle. For solid compositions (for example, powder, pill, tablet, or capsule forms), conventional non-toxic solid carriers can include, for example, pharmaceutical grades of mannitol, lactose, starch, or magnesium stearate. In addition to biologically-neutral carriers, pharmaceutical compositions to be administered can contain minor amounts of non-toxic auxiliary substances, such as wetting or emulsifying agents, preservatives, and pH buffering agents and the like, for example sodium acetate or sorbitan monolaurate.
[0165] Preventing, treating or ameliorating a disease: “Preventing” a disease (such as HCC) refers to inhibiting the full development of a disease. “Treating” refers to a therapeutic intervention that ameliorates a sign or symptom of a disease or pathological condition after it has begun to develop. “Ameliorating” refers to the reduction in the number or severity of signs or symptoms of a disease.
[0166] Screening: As used herein, “screening” refers to the process used to evaluate and identify candidate agents that affect TRAIL Expression Patterns. In some cases, screening involves contacting a candidate agent (such as an antibody, small molecule or cytokine) with TRAIL-resistant cancer cells and testing the effect of the agent on TRAIL Expression Patterns. Expression of a microRNA can be quantified using any one of a number of techniques known in the art and described herein, such as by microarray analysis or by qRT-PCR.
[0167] Small molecule: A molecule, typically with a molecular weight less than about 1000 Daltons, or in some embodiments, less than about 500 Daltons, wherein the molecule is capable of modulating, to some measurable extent, an activity of a target molecule.
[0168] Therapeutic: A generic term that includes both diagnosis and treatment.
[0169] Therapeutic agent: A chemical compound, small molecule, or other composition, such as an antisense compound, antibody, protease inhibitor, hormone, chemokine or cytokine, capable of inducing a desired therapeutic or prophylactic effect when properly administered to a subject. For example, therapeutic agents for TRAIL-resistant cancer cells include agents that prevent or inhibit development or metastasis of TRAIL-resistant cancer cells. As used herein, a “candidate agent” is a compound selected for screening to determine if it can function as a therapeutic agent for TRAIL-resistant cancer cells. In some embodiments, the candidate agent is identified as a therapeutic agent if the agent converts the cell from in TRAIL-resistant cancer cells. “Incubating” includes a sufficient amount of time for an agent to interact with a cell or tissue. “Contacting” includes incubating an agent in solid or in liquid form with a cell or tissue. “Treating” a cell or tissue with an agent includes contacting or incubating the agent with the cell or tissue.
[0170] Therapeutically effective amount: A quantity of a specified pharmaceutical or therapeutic agent sufficient to achieve a desired effect in a subject, or in a cell, being treated with the agent. For example, this can be the amount of a therapeutic agent that decreases expression of miR-221 and miR-222 and c-Jun or decreases the expression of miR-221 and miR-222 in conjunction with increasing PTEN and/or TIMP3 thereby prevents, treats or ameliorates TRAIL-resistant cancer cells in a patient. The effective amount of the agent will be dependent on several factors, including, but not limited to the subject or cells being treated, and the manner of administration of the therapeutic composition.
[0171] TRAIL Expression Pattern: the comparative expression levels of four genes in a cell, cell culture, or tissue sample, including c-Jun, miR-221 and miR-222, PTEN and TIMP3.
[0172] TRAIL-resistant TRAIL Expression Pattern: is a TRAIL expression pattern wherein c-Jun and miR-221 and miR-222 expression is high, and PTEN and TIMP3 expression is low compared to control.
[0173] TRAIL resistant cancer cells, TRAIL resistant cancer, TRAIL resistant tumor cells or tumor, and the like: cells (in vitro, in situ, in vivo) which, if challenged with TRAIL, no or little apoptosis in response to TRAIL would be observed compared to control. This definition does not require TRAIL challenge testing of every putative TRAIL resistant cell in order to meet the definition; rather, sampling, staining, phenotypic or genetic marker identification, known TRAIL status, or any other suggestion of TRAIL resistance, is within the meaning of this definition.
[0174] TRAIL-sensitive TRAIL Expression Pattern: is a TRAIL expression pattern wherein c-Jun and miR-221 and miR-222 expression is low, and PTEN and TIMP3 expression is high compared to control.
[0175] Tumor, neoplasia, malignancy or cancer: The result of abnormal and uncontrolled growth of cells. Neoplasia, malignancy, cancer and tumor are often used interchangeably and refer to abnormal growth of a tissue or cells that results from excessive cell division. The amount of a tumor in an individual is the “tumor burden” which can be measured as the number, volume, or weight of the tumor. A tumor that does not metastasize is referred to as “benign.” A tumor that invades the surrounding tissue and/or can metastasize is referred to as “malignant.”
[0176] Tumor-Node-Metastasis (TNM): The TNM classification of malignant tumors is a cancer staging system for describing the extent of cancer in a patient's body. T describes the size of the primary tumor and whether it has invaded nearby tissue; N describes any lymph nodes that are involved; and M describes metastasis. TNM is developed and maintained by the International Union Against Cancer to achieve consensus on one globally recognized standard for classifying the extent of spread of cancer. The TNM classification is also used by the American Joint Committee on Cancer and the International Federation of Gynecology and Obstetrics.
[0177] In some embodiments, the control is non-cancerous tissue sample obtained from the same patient. In other embodiments, the control is a liver sample obtained from a healthy subject, such as a healthy liver donor. In another example, the control is a standard calculated from historical values. Tumor samples and non-cancerous tissue samples can be obtained according to any method known in the art. For example, tumor and non-cancerous samples can be obtained from HCC patients that have undergone liver resection, or they can be obtained by extraction using a hypodermic needle, by microdissection, or by laser capture. Control (non-cancerous) samples can be obtained, for example, from a cadaveric donor or from a healthy liver donor.
[0178] In some embodiments, screening comprises contacting the candidate agents with cells. The cells can be primary cells obtained from a patient, or the cells can be immortalized or transformed cells.
[0179] The candidate agents can be any type of agent, such as a protein, peptide, small molecule, antibody or nucleic acid. In some embodiments, the candidate agent is a cytokine. In some embodiments, the candidate agent is a small molecule. Screening includes both high-throughout screening and screening individual or small groups of candidate agents.
[0180] Methods of Detecting RNA Expression
[0181] The sequences of precursor microRNAs (pre-miRNAs) and mature miRNAs are publicly available, such as through the miRBase database, available online by the Sanger Institute (see Griffiths-Jones et al., Nucleic Acids Res. 36:D154-D158, 2008; Griffiths-Jones et al., Nucleic Acids Res. 34:D140-D144, 2006; and Griffiths-Jones, Nucleic Acids Res. 32: D109-D111, 2004).
[0182] Detection and quantification of RNA expression can be achieved by any one of a number of methods well known in the art (see, for example, U.S. Patent Application Publication Nos. 2006/0211000 and 2007/0299030, herein incorporated by reference) and described below. Using the known sequences for RNA family members, specific probes and primers can be designed for use in the detection methods described below as appropriate.
[0183] In some cases, the RNA detection method requires isolation of nucleic acid from a sample, such as a cell or tissue sample. Nucleic acids, including RNA and specifically miRNA, can be isolated using any suitable technique known in the art. For example, phenol-based extraction is a common method for isolation of RNA. Phenol-based reagents contain a combination of denaturants and RNase inhibitors for cell and tissue disruption and subsequent separation of RNA from contaminants. Phenol-based isolation procedures can recover RNA species in the 10-200-nucleotide range (e.g., precursor and mature miRNAs, 5S and 5.8S ribosomal RNA (rRNA), and UI small nuclear RNA (snRNA)). In addition, extraction procedures such as those using TRIZOL™ or TRI REAGENT™, will purify all RNAs, large and small, and are efficient methods for isolating total RNA from biological samples that contain miRNAs and small interfering RNAs (siRNAs).
[0184] Microarray
[0185] A microarray is a microscopic, ordered array of nucleic acids, proteins, small molecules, cells or other substances that enables parallel analysis of complex biochemical samples. A DNA microarray consists of different nucleic acid probes, known as capture probes that are chemically attached to a solid substrate, which can be a microchip, a glass slide or a microsphere-sized bead. Microarrays can be used, for example, to measure the expression levels of large numbers of messenger RNAs (mRNAs) and/or miRNAs simultaneously.
[0186] Microarrays can be fabricated using a variety of technologies, including printing with fine-pointed pins onto glass slides, photolithography using pre-made masks, photolithography using dynamic micromirror devices, ink-jet printing, or electrochemistry on microelectrode arrays.
[0187] Microarray analysis of miRNAs, for example (although these procedures can be used in modified form for any RNA analysis) can be accomplished according to any method known in the art (see, for example, PCT Publication No. WO 2008/054828; Ye et al., Nat. Med. 9(4):416-423, 2003; Calin et al., N. Engl. J. Med. 353(17):1793-1801, 2005, each of which is herein incorporated by reference). In one example, RNA is extracted from a cell or tissue sample, the small RNAs (18-26-nucleotide RNAs) are size-selected from total RNA using denaturing polyacrylamide gel electrophoresis. Oligonucleotide linkers are attached to the 5′ and 3′ ends of the small RNAs and the resulting ligation products are used as templates for an RT-PCR reaction with 10 cycles of amplification. The sense strand PCR primer has a fluorophore attached to its 5′ end, thereby fluorescently labeling the sense strand of the PCR product. The PCR product is denatured and then hybridized to the microarray. A PCR product, referred to as the target nucleic acid that is complementary to the corresponding miRNA capture probe sequence on the array will hybridize, via base pairing, to the spot at which the capture probes are affixed. The spot will then fluoresce when excited using a microarray laser scanner. The fluorescence intensity of each spot is then evaluated in terms of the number of copies of a particular miRNA, using a number of positive and negative controls and array data normalization methods, which will result in assessment of the level of expression of a particular miRNA.
[0188] In an alternative method, total RNA containing the small RNA fraction (including the miRNA) extracted from a cell or tissue sample is used directly without size-selection of small RNAs, and 3′ end labeled using T4 RNA ligase and either a fluorescently-labeled short RNA linker. The RNA samples are labeled by incubation at 30° C. for 2 hours followed by heat inactivation of the T4 RNA ligase at 80° C. for 5 minutes. The fluorophore-labeled miRNAs complementary to the corresponding miRNA capture probe sequences on the array will hybridize, via base pairing, to the spot at which the capture probes are affixed. The microarray scanning and data processing is carried out as described above.
[0189] There are several types of microarrays than be employed, including spotted oligonucleotide microarrays, pre-fabricated oligonucleotide microarrays and spotted long oligonucleotide arrays. In spotted oligonucleotide microarrays, the capture probes are oligonucleotides complementary to miRNA sequences. This type of array is typically hybridized with amplified PCR products of size-selected small RNAs from two samples to be compared (such as non-cancerous tissue and HCC liver tissue) that are labeled with two different fluorophores. Alternatively, total RNA containing the small RNA fraction (including the miRNAs) is extracted from the two samples and used directly without size-selection of small RNAs, and 3′ end labeled using T4 RNA ligase and short RNA linkers labeled with two different fluorophores. The samples can be mixed and hybridized to one single microarray that is then scanned, allowing the visualization of up-regulated and down-regulated miRNA genes in one assay.
[0190] In pre-fabricated oligonucleotide microarrays or single-channel microarrays, the probes are designed to match the sequences of known or predicted miRNAs. There are commercially available designs that cover complete genomes (for example, from Affymetrix or Agilent). These microarrays give estimations of the absolute value of gene expression and therefore the comparison of two conditions requires the use of two separate microarrays.
[0191] Spotted long Oligonucleotide Arrays are composed of 50 to 70-mer oligonucleotide capture probes, and are produced by either ink jet or robotic printing. Short Oligonucleotide Arrays are composed of 20-25-mer oligonucleotide probes, and are produced by photolithographic synthesis (Affymetrix) or by robotic printing.
[0192] Quantitative RT-PCR
[0193] Quantitative RT-PCR (qRT-PCR) is a modification of polymerase chain reaction used to rapidly measure the quantity of a product of polymerase chain reaction. qRT-PCR is commonly used for the purpose of determining whether a genetic sequence, such as a miR, is present in a sample, and if it is present, the number of copies in the sample. Any method of PCR that can determine the expression of a nucleic acid molecule, including a miRNA, falls within the scope of the present disclosure. There are several variations of the qRT-PCR method known in the art, three of which are described below.
[0194] Methods for quantitative polymerase chain reaction include, but are not limited to, via agarose gel electrophoresis, the use of SYBR Green (a double stranded DNA dye), and the use of a fluorescent reporter probe. The latter two can be analyzed in real-time.
[0195] With agarose gel electrophoresis, the unknown sample and a known sample are prepared with a known concentration of a similarly sized section of target DNA for amplification. Both reactions are run for the same length of time in identical conditions (preferably using the same primers, or at least primers of similar annealing temperatures). Agarose gel electrophoresis is used to separate the products of the reaction from their original DNA and spare primers. The relative quantities of the known and unknown samples are measured to determine the quantity of the unknown.
[0196] The use of SYBR Green dye is more accurate than the agarose gel method, and can give results in real time. A DNA binding dye binds all newly synthesized double stranded DNA and an increase in fluorescence intensity is measured, thus allowing initial concentrations to be determined. However, SYBR Green will label all double-stranded DNA, including any unexpected PCR products as well as primer dimers, leading to potential complications and artifacts. The reaction is prepared as usual, with the addition of fluorescent double-stranded DNA dye. The reaction is run, and the levels of fluorescence are monitored (the dye only fluoresces when bound to the double-stranded DNA). With reference to a standard sample or a standard curve, the double-stranded DNA concentration in the PCR can be determined.
[0197] The fluorescent reporter probe method uses a sequence-specific nucleic acid based probe so as to only quantify the probe sequence and not all double stranded DNA. It is commonly carried out with DNA based probes with a fluorescent reporter and a quencher held in adjacent positions (so-called dual-labeled probes). The close proximity of the reporter to the quencher prevents its fluorescence; it is only on the breakdown of the probe that the fluorescence is detected. This process depends on the 5′ to 3′ exonuclease activity of the polymerase involved.
[0198] The real-time quantitative PCR reaction is prepared with the addition of the dual-labeled probe. On denaturation of the double-stranded DNA template, the probe is able to bind to its complementary sequence in the region of interest of the template DNA. When the PCR reaction mixture is heated to activate the polymerase, the polymerase starts synthesizing the complementary strand to the primed single stranded template DNA. As the polymerization continues, it reaches the probe bound to its complementary sequence, which is then hydrolyzed due to the 5′-3′ exonuclease activity of the polymerase, thereby separating the fluorescent reporter and the quencher molecules. This results in an increase in fluorescence, which is detected. During thermal cycling of the real-time PCR reaction, the increase in fluorescence, as released from the hydrolyzed dual-labeled probe in each PCR cycle is monitored, which allows accurate determination of the final, and so initial, quantities of DNA.
[0199] In Situ Hybridization
[0200] In situ hybridization (ISH) applies and extrapolates the technology of nucleic acid hybridization to the single cell level, and, in combination with the art of cytochemistry, immunocytochemistry and immunohistochemistry, permits the maintenance of morphology and the identification of cellular markers to be maintained and identified, and allows the localization of sequences to specific cells within populations, such as tissues and blood samples. ISH is a type of hybridization that uses a complementary nucleic acid to localize one or more specific nucleic acid sequences in a portion or section of tissue (in situ), or, if the tissue is small enough, in the entire tissue (whole mount ISH). RNA ISH can be used to assay expression patterns in a tissue, such as the expression of miRNAs.
[0201] Sample cells or tissues are treated to increase their permeability to allow a probe, such as a miRNA-specific probe, to enter the cells. The probe is added to the treated cells, allowed to hybridize at pertinent temperature, and excess probe is washed away. A complementary probe is labeled with a radioactive, fluorescent or antigenic tag, so that the probe's location and quantity in the tissue can be determined using autoradiography, fluorescence microscopy or immunoassay. The sample may be any sample as herein described, such as a non-cancerous or HCC liver sample. Since the sequences of miR-26 family members are known, miR-26 probes can be designed accordingly such that the probes specifically bind miR-26.
[0202] In Situ PCR
[0203] In situ PCR is the PCR based amplification of the target nucleic acid sequences prior to ISH. For detection of RNA, an intracellular reverse transcription step is introduced to generate complementary DNA from RNA templates prior to in situ PCR. This enables detection of low copy RNA sequences.
[0204] Prior to in situ PCR, cells or tissue samples are fixed and permeabilized to preserve morphology and permit access of the PCR reagents to the intracellular sequences to be amplified. PCR amplification of target sequences is next performed either in intact cells held in suspension or directly in cytocentrifuge preparations or tissue sections on glass slides. In the former approach, fixed cells suspended in the PCR reaction mixture are thermally cycled using conventional thermal cyclers. After PCR, the cells are cytocentrifuged onto glass slides with visualization of intracellular PCR products by ISH or immunohistochemistry. In situ PCR on glass slides is performed by overlaying the samples with the PCR mixture under a coverslip which is then sealed to prevent evaporation of the reaction mixture. Thermal cycling is achieved by placing the glass slides either directly on top of the heating block of a conventional or specially designed thermal cycler or by using thermal cycling ovens.
[0205] Detection of intracellular PCR products is generally achieved by one of two different techniques, indirect in situ PCR by ISH with PCR-product specific probes, or direct in situ PCR without ISH through direct detection of labeled nucleotides (such as digoxigenin-11-dUTP, fluorescein-dUTP, 3H-CTP or biotin-16-dUTP), which have been incorporated into the PCR products during thermal cycling.
[0206] Use of miR-221 and miR-222 and c-Jun, PTEN and TIMP3 as predictive markers of prognosis and for identification of therapeutic agents for treatment of TRAIL resistant cancer cells
[0207] It is disclosed herein that expression patterns of miR-221 and miR-222, c-Jun, PTEN and TIMP3 are predictors of survival prognosis in TRAIL-resistant patients. TRAIL resistant cancer cells samples (for example, tissue biopsy samples) with high miR-221 and miR-222 and c-Jun expression, along with low PTEN and TIMP3 expression compared to non-cancerous tissue from the same subject or from a healthy subject, predicts a decrease in survival. Thus, the TRAIL Resistant Expression Pattern status in tumors can be used as a clinical tool in TRAIL-resistant cancer patients' prognosis.
[0208] In some embodiments, the expression level of the markers herein in a TRAIL-resistant tumor sample is directly compared with the TRAIL Resistant Expression Pattern in surrounding non-cancerous tissue from the same patient.
[0209] In other embodiments, TRAIL Resistant Expression Pattern in the tumor sample is compared to the TRAIL Resistant Expression Pattern in a liver sample obtained from a healthy subject, such as a liver donor. In some cases, the non-cancerous tissue used as a control sample is obtained from a cadaver. In other embodiments, the TRAIL Resistant Expression Pattern in the tumor sample is compared with a standard level based on historical values. For example, the standard can be set based on average Trail Resistant Expression Pattern in non-cancerous liver tissue samples obtained from a cohort of subjects. For instance, the cohort of subjects can be a group of HCC patients enrolled in a clinical trial. The cohort of subject can also be a group of cadaveric donors.
[0210] Finding a TRAIL Resistant Expression Pattern in a HCC tumor sample relative to a control indicates a poor prognosis for the patient and identifies the patient as a good candidate for specialized therapy. As used herein, “poor prognosis” generally refers to a decrease in survival, or in other words, an increase in risk of death or a decrease in the time until death. Poor prognosis can also refer to an increase in severity of the disease, such as an increase in spread (metastasis) of the cancer to other organs. In one embodiment, TRAIL Resistant Expression Pattern is found when the respective markers show at least a 1.5-fold increase or decrease in expression relative to the control. In other embodiments, TRAIL Resistant Expression Pattern is indicated by at least a 2-fold, at least a 2.5-fold, at least a 3-fold, at least a 3.5-fold, or at least a 4-fold increase or decrease in the markers of TRAIL Resistant Expression Pattern relative to the control.
[0211] The finding that patients with TRAIL resistant tumors having a TRAIL sensitive Expression Pattern have a better chance of survival indicates that compounds that decrease c-Jun, miR-221 and miR-222 expression in conjunction with increasing PTEN and TIMP3 expression will be useful as therapeutic agents for the treatment of TRAIL resistant tumors.
[0212] Thus, provided herein is a method of identifying therapeutic agents for the treatment of TRAIL resistant cancer cells, comprising screening candidate agents in vitro to select an agent that promote conversion from TRAIL Resistant TRAIL Expression Pattern to TRAIL Sensitive TRAIL Expression Pattern. In some embodiments, screening comprises contacting the candidate agents with TRAIL resistant cancer cells and detecting any change TRAIL Expression Pattern. The TRAIL resistant cancer cells can be primary cells obtained from a patient, immortalized or transformed cells obtained from a patient, or the cells can be commercially available immortalized cell lines, such as, but not limited to MHCC97, HepG2, Hep3B or SNU-423 cells.
[0213] A conversion to TRAIL sensitive Expression Pattern following treatment with the candidate agent identifies the agent as a therapeutic agent for the treatment of TRAIL resistant cancer. Methods of screening candidate agents to identify therapeutic agents for the treatment of disease are well known in the art. Methods of detecting expression levels of RNA and proteins are known in the art and are described herein, such as, but not limited to, microarray analysis, RT-PCR (including qRT-PCR), in situ hybridization, in situ PCR, and Northern blot analysis. In one embodiment, screening comprises a high-throughput screen. In another embodiment, candidate agents are screened individually.
[0214] The candidate agents can be any type of molecule, such as, but not limited to nucleic acid molecules, proteins, peptides, antibodies, lipids, small molecules, chemicals, cytokines, chemokines, hormones, or any other type of molecule that may alter TRAIL Expression Pattern(s) either directly or indirectly. In some embodiments, the candidate agents are molecules that play a role in the NFκB/IL-6 signaling pathway. In other embodiments, the candidate agents are molecules that play a role in the IL-10, STAT3 or interferon-inducible factor signaling networks. In one embodiment, the candidate agents are cytokines. In another embodiment, the candidate agents are small molecules.
[0215] Also described herein is a method for the characterization of TRAIL resistant cancer, wherein at least one feature of TRAIL resistant cancer is selected from one or more of the group consisting of: presence or absence of TRAIL resistant cancer; diagnosis of TRAIL resistant cancer; prognosis of TRAIL resistant cancer; therapy outcome prediction; therapy outcome monitoring; suitability of TRAIL resistant cancer to treatment, such as suitability of TRAIL resistant cancer to chemotherapy treatment and/or radiotherapy treatment; suitability of TRAIL resistant cancer to hormone treatment; suitability of TRAIL resistant cancer for removal by invasive surgery; suitability of TRAIL resistant cancer to combined adjuvant therapy.
[0216] Also described herein is a kit for the detection of TRAIL resistant cancer, the kit comprising at least one detection probe comprising c-Jun and miR-221 and miR-222 or miR-221 and miR-222 and PTEN and/or TIMP3. The kit can be in the form or comprises an oligonucleotide array.
[0217] Also described herein is a method for the determination of suitability of a TRAIL resistant cancer patient for treatment comprising: i) isolating at least one tissue sample from a patient suffering from TRAIL resistant cancer; ii) performing the characterization of at least one tissue sample and/or utilizing a detection probe, to identify the TRAIL Expression Pattern; iii) based on the at least one feature identified in step ii), diagnosing the physiological status of the patient; iv) based on the diagnosis obtained in step iii), determining whether the patient would benefit from treatment of the TRAIL resistant cancer.
[0218] In certain embodiments, the at least one feature of the cancer is selected from one or more of the group consisting of: presence or absence of the cancer; type of the cancer; origin of the cancer; diagnosis of cancer; prognosis of the cancer; therapy outcome prediction; therapy outcome monitoring; suitability of the cancer to treatment, such as suitability of the cancer to chemotherapy treatment and/or radiotherapy treatment; suitability of the cancer to hormone treatment; suitability of the cancer for removal by invasive surgery; suitability of the cancer to combined adjuvant therapy.
[0219] Also described herein is a method of for the determination of suitability of a cancer for treatment, wherein the at least one feature of the cancer is suitability of the cancer to treatment, such as suitability of the cancer to chemotherapy treatment and/or radiotherapy treatment; suitability of the cancer to hormone treatment; suitability of the cancer for removal by invasive surgery; suitability of the cancer to combined adjuvant therapy.
[0220] Also described herein is a method for the determination of the likely prognosis of a cancer patient comprising: i) isolating at least one tissue sample from a patient suffering from cancer; and, ii) characterizing at least one tissue sample to identify the TRAIL Expression Pattern; wherein the feature allows for the determination of the likely prognosis of the cancer patient.
[0221] The following examples are provided to illustrate certain particular features and/or embodiments. These examples should not be construed to limit the disclosure to the particular features or embodiments described.
EXAMPLES
Example I
miR-221 and miR-222 Directly Target PTEN and TIMP3 3′UTRs
[0222] To identify putative miR-221 and miR-222 targets, a bioinformatics search (Targetscan, Pictar, RNhybrid) was conducted. Among the candidate targets, 3′-UTRs of human PTEN (nucleotides 200-207, NM — 000314) and human TIMP3 (nucleotides 2443-2449, NM — 000362) contained regions that matched the seed sequences of hsa-miR-221 and miR-222 ( FIG. 1A ). To ascertain whether PTEN and TIMP3 are direct targets of miR-221 and miR-222, PTEN and TIMP3 3′ UTR containing the miR-221/miR-222 binding sites were cloned downstream of the luciferase open reading frame. These reporter constructs were used to transfect MEG01 cells, which express very low levels of miR-221 and miR-222 ( FIG. 1B ) and are highly transfectable (Freson et al., 2005). Increased expression of these miRs upon transfection, confirmed by qRT-PCR ( FIG. 1B ), significantly affected luciferase expression, measured as relative luciferase activity ( FIG. 1C ). Conversely, when luciferase assays were performed by using a plasmid harboring the 3′ UTR of PTEN and TIMP3 mRNAs, where the binding sites for miR-221 and miR-222 were inactivated by site-directed mutagenesis, there was observed a consistent reduction in miR-221 and miR-222 inhibitory effect ( FIG. 1C ). To determine if these microRNAs affect PTEN and TIMP3 expression in the H460 cellular environment, the consequences of the ectopic expression of miR-221 and miR-222 in H460 cells were analyzed. Increased expression of these miRs upon transfection was confirmed by qRT-PCR ( FIG. 1D ) and then the effects on endogenous levels of PTEN and TIMP3 were analyzed by Western blot ( FIG. 1E ); miR-221 and miR-222 over-expression significantly reduced the endogenous levels of PTEN and TIMP3, compared to H460 cells transfected with scrambled pre-miR. Conversely, knockdown of miR-221 and miR-222 by 2′-O-me-anti-miR-221 and 2′-O-me-anti-miR-222, confirmed by qRT-PCR ( FIG. 1F ) in Calu-1-lung derived cells with high levels of endogenous miR-221 and miR-222, increased the protein levels of PTEN and TIMP3 ( FIG. 1G ). Intriguingly, by quantitative RT-PCR, it was found that PTEN, but not TIMP3 mRNA levels, were strongly reduced in the miR-221 and miR-222 transfected cells ( FIG. 1H ), indicating that miR-221 and miR-222 induce the degradation of PTEN mRNA while TIMP3 is regulated by these microRNAs only at the translational level. PTEN and TIMP3 3′UTRs are therefore direct targets of miR-221 and miR-222.
Example II
mir-221 and miR-222 are Inversely Correlated with PTEN and TIMP3 Expression in NSCLC and HCC
[0223] The endogenous levels of miR-221 and miR-222 were evaluated by Northern blot in large panels of primary NSCLCs and HCCs, compared with the normal counterpart. miR-221 and miR-222 expression was almost undetectable in normal lung and liver cells but highly expressed in the majority of tumor cell lines. Moreover, as assessed by Western blot, an inverse correlation between miR-221 and miR-222 RNA expression and PTEN and TIMP3 protein expression was found in most cell lines analyzed ( FIG. 2A ), confirmed also by qRT-PCR ( FIG. 2B ). TIMP3 mRNA expression levels was not tested because down-regulation of TIMP3 mRNA after enforced miR-221 and miR-222 expression was not observed ( FIG. 1H ). These results indicate that high expression of miR-221 and miR-222 is one of the mechanisms acting to negatively regulate PTEN and TIMP3 in NSCLC and HCC.
[0224] To verify whether these microRNAs affected PTEN and TIMP3 endogenous levels also in HCC, analysis of the effects of the ectopic expression of miR-221 and miR-222 in the Sk-Hep1 cell line, which expresses low levels of miR-221 and miR-222, was performed. As shown in FIG. 3A , PTEN and TIMP3 proteins were reduced in Sk-Hep1 cells upon miR-221 and miR-222 over-expression. Conversely, knockdown of miR-221 and miR-222 by 2′-O-me-anti-miR-221 and 2′-O-me-anti-miR-222 in Snu-387 cells, which expressed high levels of endogenous miR-221 and miR-222, increased the protein level of PTEN and TIMP3 ( FIG. 3A ).
[0225] Having noted that miR-221 and miR-222 down-regulate PTEN and TIMP3 expression in both NSCLC and HCC-derived cells in culture, regulation in vivo was studied. To answer this question, PTEN mRNA and miR-221 and miR-222 expression by qRT-PCR in primary lung tumor specimens was studied, in comparison with normal human lung tissue samples. miR-221 and miR-222 were almost undetectable in normal human lung samples and highly expressed in all the tumor samples analyzed. Of the 22 primary lung tumors examined, in fact, all exhibited down-regulation of PTEN and over-expression of miR-221 and miR-222 ( FIG. 3B ). These data further support the finding that PTEN is a direct target of miR-221 and miR-222 also in vivo.
[0226] To corroborate these findings, in situ hybridization analysis was performed, by using 5′-dig-labeled LNA probes, on hepatocarcinoma and normal liver tissues, followed by immunohistochemistry for PTEN and TIMP3 ( FIG. 3C ). miR-221/miR-222 and PTEN/TIMP3 expressions were inversely related in liver cancers and the adjacent normal/cirrhotic liver tissues. Liver cancer cells showed high expression of miR-221/miR-222 and rarely expressed PTEN or TIMP3 (FIGS. 3 CG-H-K-L) whereas the adjacent non-malignant liver expressed PTEN and TIMP3 abundantly and rarely showed detectable miR-221/miR-222 signal (FIGS. 3 CA-B-E-F). miR-221/miR-222 and PTEN/TIMP3 expression were also inversely related in lung cancers and the adjacent normal lung tissues ( FIG. 9 ). The majority of cancer cells were positive for miR-221 and miR-222 and negative for PTEN ( FIGS. 9F-9G ) and TIMP3 ( FIGS. 9I-9J ). In FIGS. 9I-9J miRNA expression was evident in the cancer cells and TIMP3 expression in the surrounding cells. A strong miR-222 signal (large arrow) was found in the nests of tumor cells that are infiltrating the adjacent fibrotic lung tissue ( FIGS. 9K-9L ).
Example III
miR-221 and miR-222 Induce TRAIL Resistance in NSCLC and HCC by Targeting PTEN and TIMP3
[0227] The effects of miR-221 and miR-222 and/or PTEN-TIMP3 silencing on cell survival and TRAIL resistance in both NSCLC and HCC were studied. First there was performed a proliferation assay on 5 HCC-derived cell lines, three of them (HepG2, Sk-Hep1 and Huh 7) with low miR-221-miR-222 expression and two (PLC/PRF-5 and Snu-387) with high miR-221-miR-222 expression level ( FIG. 4A ). Cells were exposed to TRAIL for 24 hours and subsequently cell proliferation was assessed using an MTT assay. Interestingly, cells expressing low levels of miR-221 and miR-222 underwent TRAIL-induced cell death, showing a very low proliferation rate, whereas cells over-expressing miR-221 and miR-222 did not display sensitivity when exposed to soluble TRAIL ( FIG. 4A ).
[0228] Moreover, Annexin-FITC and caspase 3/7 assays on TRAIL-sensitive cell lines Sk-Hep1 cells, ( FIGS. 4B-4C ), HepG2 and Huh7 ( FIGS. 10A-10B ), revealed an increase of about 30-40% in TRAIL resistance after miR-221 and miR-222 over-expression, as well as after PTEN and TIMP3 silencing by PTEN and TIMP3 siRNAs. TRAIL-sensitive H460 cells also became more resistant to TRAIL inducing-apoptosis after PTEN and TIMP3 knockdown, as determined by caspase 3/7 activity ( FIG. 4D ) and Annexin-FITC assay ( FIG. 4E ), although PTEN silencing was more effective than TIMP3.
[0229] Moreover, to further evaluate the contribution of these targets on TRAIL-inducing apoptosis, PTEN and TIMP3 sequences were cloned in pCruz-HA plasmid (Santa Cruz) and used to transfect Calu-1 TRAIL-resistant cells. Calu-1 cells became more sensitive to TRAIL inducing-apoptosis after PTEN and TIMP3 restoration, alone or in combination, as determined by caspase 3/7 activity ( FIG. 4D ) and Annexin-FITC staining ( FIGS. 11A-11B ). To further investigate the role of TIMP3 in TRAIL-inducing apoptosis the expression of caspase-3,-8 -9, poly-ADP-ribose polymerase (PARP) and some of the molecule involved in the TRAIL-signaling pathway were tested by western blot after TIMP3 overexpression in Calu-1 cell line ( FIG. 11C ). Interestingly, the activation of PARP and the caspase cascade were observed, as assessed by the appearance of the cleaved fragments. Moreover, Mcl-1 expression was down-regulated while cytochrome c expression increased ( FIG. 11C ).
[0230] All together these results suggest an involvement of TIMP3 in both the extrinsic and intrinsic apoptotic pathways and highlight its role in TRAIL-inducing apoptosis. The same results were obtained after TIMP3 restoration in Snu-387 cells (data not shown).
[0231] Further, the expression and/or the activation of some of the proteins involved in the PI3K/AKT pathway after miR-221 and miR-222 enforced expression in H460 cells or after miR-221/miR-222 silencing in Snu-387 cells was conducted. As shown in FIG. 5A , the expression levels of PI3K, AKT and its phosphorylated substrate, phospho-glycogen synthase kinase 3, were elevated by ectopic expression of miR-221 and miR-222, and, in contrast, were decreased by knockdown of miR-221 and miR-222 in Snu-387 cells, indicating that miR-221 and miR-222 target the PTEN/AKT pathway ( FIG. 5B ).
[0232] Further investigation of the activation and expression levels of these proteins was conducted. There was found an increase in ERKs phosphorylation and PAK1 expression, as compared with H460 cells transfected with the control miR ( FIG. 5C ). Interestingly, increased expression of metallopeptidase 3 and metallopeptidase 9 was also found, as possible result of TIMP3 down-regulation ( FIGS. 5A-5C ). To test if the activation of the previous proteins was PTEN and/or TIMP3-dependent, PTEN and TIMP3 were silenced in H460 cells. As shown in FIGS. 5D and E the activation of the ERKs and PAK1 is both PTEN and TIMP3-dependent, while AKT phosphorylation is PTEN-dependent and MMP3 and MMP9 are upregulated after TIMP3 knockdown.
[0233] Finally, AKT inhibition was studied, as it relates to whether it could override miR-221 and miR-222-induced cell survival and TRAIL-resistance. Calu-1 and Snu-387 were transfected with 2′-O-methyl (2′-O-me)-anti-miR-221 and miR-222 oligoribonucleotides. Cells transfected with 2′-0-me-scrambled miR were used as control. Blocking miR-221 and miR-222 expression considerably sensitized these cells to TRAIL-induced apoptosis, as assessed by caspase 3/7 assay ( FIGS. 5F-5G ). Moreover, Calu-1 and Snu-387 cells were treated with the specific AKT inhibitor, API-2/triciribine, with or without TRAIL. As shown in FIGS. 5F and 50 , API-2 abrogated miR 221 and miR-222-activated AKT and significantly inhibited miR-221 and miR-222-induced cell survival and TRAIL resistance.
[0234] Next, to directly compare the growth of tumors with and without PTEN and TIMP3, short hairpin RNA (shRNA) constructs, designed to knockdown gene expression, were used to silence PTEN and TIMP3 in H460 cells. An shRNA plasmid, encoding a scrambled shRNA sequence that does not lead to the specific degradation of any known cellular mRNA, was used as control. The consequences of PTEN and TIMP3 disruption on tumor growth and TRAIL resistance was assessed in vivo by implanting H460 PTEN and TIMP3 knockdown cells into the right dorsal sides of nude mice. TRAIL treatment was initiated 5 days afterwards, when lung carcinoma had been established. PTEN and TIMP3 loss ( FIG. 12A ) conferred not only a significant tumor growth advantage but also resistance to TRAIL-inducing apoptosis over control tumors (FIGS. 124 B- 12 C- 12 D- 2 E- 12 F- 12 G).
[0235] In conclusion, PTEN and TIMP3 are important targets in TRAIL resistance and play an important role in tumorigenicity of NSCLC and HCC cells.
Example IV
PTEN and TIMP3 Down-Regulation by miR-221 and miR-222 Induces Migration and Invasiveness in NSCLC and HCC Cells
[0236] To directly test the functional role of miR-221/miR-222 in tumorigenesis, these two microRNAs were over-expressed, or PTEN and TIMP3 were silenced, in H460 and Sk-Hep1 cells. Then, by cell cycle analysis, miR-221 and miR-222 and PTEN siRNA H460 transfected cells showed a decrease of 01 and a corresponding increase of the S and G2-M phases ( FIG. 6A ). After 72 h of transfection the analysis revealed an earlier onset of DNA synthesis induced by miR-221 and miR-222 or PTEN knockdown, paralleled by a faster reduction of 01 cells, contributing to the proliferative advantage ( FIG. 6A ). The same change was observed in Sk-Hep1 cells ( FIG. 13A ).
[0237] Next, the inventors analyzed the effects of miR-221 and miR-222 over-expression on cellular migration and invasion of NSCLC and HCC cells. Interestingly, a significant increase on the migratory ( FIGS. 6B-6C ) and invasive ( FIG. 6D ) capabilities of H460 and Sk-Hep1 ( FIG. 113B ) cells after miR-221 and miR-222 overexpression as well after PTEN and TIMP3 downregulation was observed. Conversely, when miR-221 and miR-222 were down-regulated by transfection with 2′-O-me-anti-miR-221 and miR-222, a decrease in cell migration and invasion in both Calu-1 and Snu-387 cells ( FIGS. 14A-14B ) was observed.
Example V
MET Controls miR-221 and miR-222 Activation Through AP-1 Transcription Factor
[0238] MET was silenced by using siRNA, in Calu-1 and Snu-387 cells and in a gastric cell line (GTL16), previously reported to over-express MET oncogene due to DNA amplification (Giordano et al., 1989). First, miR-221 and miR-222 expression levels were evaluated by qRT-PCR. After MET knockdown, miR-221 and miR-222 expression was down-regulated in all cell lines analyzed (FIGS. 7 A- 7 B- 7 C). The same result was obtained by treating GTL16 cells with a MET inhibitor, SU11274 ( FIG. 15A ).
[0239] Secondly, by immunostaining, there was observed increased PTEN and TIMP3 expression levels after MET down-regulation or inhibition, indicating that MET is involved in miR-221 and miR-222 activation (FIGS. 7 D- 7 E- 7 F).
[0240] Next, by bioinformatics search (TESS database: http://www.cbil.upenn.edu/cgi-bin/tess/tess), it was found that the only transcription factor involved in the MET pathway predicted to bind and transcriptionally activate miR-221/miR-222 promoter was AP-1. AP-1 is a dimeric basic region-leucine zipper protein that belongs to the Jun and Fos subfamilies c-Jun is the most potent transcriptional activator in its group.
[0241] To identify which factor belonging to the AP-1 family was involved in miR-221/miR-222 transcriptional activation, the correlation between miR-221 and miR-222 expression and c-Jun and c-Fos protein levels in 4 different cell lines (H460, Calu-1, Huh7 and Snu-387) (FIG. S 7 B) was studied. Calu-1, highly expressing c-Jun and c-Fos, were co-transfected with MET siRNA, c-Jun siRNA or c-Fos siRNA. Subsequent qRT-PCR amplification showed that MET and c-Jun down-regulation, but not c-Fos knockdown, gave rise to a reduction of ˜45-50% in miR-221 and miR-222 expression levels, as compared with the negative control (FIG. S 7 C).
[0242] To further confirm these results luciferase assays were conducted. In previous work, the inventors found that miR-221 and miR-222 are transcribed into a single species of 2.1 kb RNA and the transcription is regulated by the upstream sequence located at −150 bp/50 bp from the 5′ end of miR-222 hairpin structure. To determine if the previously identified miR-221 and miR-222 promoter region was affected by MET/AP1, the luciferase assay was performed by using the reporter plasmids containing the fragments spanning +3˜−150, +3˜−600, +3˜−1000 (+1 position corresponds to the 5′ terminus of miR-222 hairpin) ( FIG. 7G ) into the pGL3basic vector which harbors the promoter-less luciferase gene (Di Leva et al., unpublished data). The pGL3b, −150, −600 and −1000 pGL3b were co-transfected with MET siRNA, c-Jun siRNA or c-Fos siRNA into Calu-1 cells ( FIGS. 15D-15E ).
[0243] Subsequent luciferase assays showed that MET and c-Jun down-regulation gave rise to a reduction of ˜45% in luciferase activity, as compared to the basal activity determined by transfection with pGL3b empty vector; the inventors did not observe a reduction of luciferase activity after c-Fos siRNA transfection ( FIGS. 15D-15E ).
[0244] These data indicate that c-Jun and not c-Fos is the transcription factor involved in the MET pathway, responsible for miR-221 and miR-222 activation in NSCLC and HCC cells.
[0245] Since the promoter region was responsive to c-Jun modulation, to verify a direct binding of c-Jun on miR-221 and miR-222 promoter, a chromatin immunoprecipitation (ChIP) assays was conducted. First, by bioinformatics analysis, it was found that only one AP-1 putative binding site is located ˜130 bp upstream of the premiR-222-5′ end. Taking into account the predicted AP-1 binding site, a total of 2 chromatin regions were analyzed ( FIG. 7G ): one spanning the AP-1 binding site and the second, as negative control, ˜1700 nt upstream of the pre-miR-222-5′ end, where the inventors did not find any predicted binding site for AP-1. The ChIP assay of c-Jun positive Calu-1 and Snu-387 cells showed remarkable AP-1 binding at ChIP analyzed region 2, proximal to the promoter ( FIGS. 7H-7I ). No chromatin enrichment by c-Jun ChIP was observed in c-Jun negative H460 cells, verifying the specificity of the ChIP assay.
[0246] Finally, Huh7 cells, which show low levels of miR-221 and miR-222, were treated with anisomycin, an antibiotic able to activate JNK kinases, and, thus AP-1, miR-221 and miR-222 and PTEN-TIMP3 expression levels were checked. After c-Jun activation ( FIG. 7M ) by anisomycin, miR-221 and -222 expression increased (miR-221=80%, miR-222=40%) as confirmed by qRT-PCR ( FIG. 7L ), while PTEN and TIMP3 expression levels were decreased drastically ( FIG. 7M ). To further prove that JNK is the intermediate signaling factor between c-Met and c-Jun and that c-Jun knockdown leads to increased PTEN and TIMP3 expression, c-Met and c-Jun in Calu-1 cells were studied and the JNK½ phosphorylation and PTEN and TIMP3 expression were analyzed, respectively. As shown in FIG. S 7 F, MET knockdown reduces JNK½ phosphorylation while c-Jun silencing increases PTEN/TIMP3 expression as result of miR-221 and miR-222 down modulation.
[0247] To investigate whether there is a direct relation between MET and PTEN/TIMP3 in vivo, immunohistochemistry analysis was performed on lung and liver cancer and normal samples. The co-labeling MET/PTEN and MET/TIMP3 showed that PTEN and TIMP3 are abundantly expressed only in the normal cells, where MET is not present, whereas c-Met is expressed exclusively in the cancer cells ( FIG. 16 ). These data confirm that MET is implicated in miR-221 and miR-222 regulation, at least in part through JNK, AP-1 and in particular c-Jun transcription factor.
Example VI
Experimental Procedures
[0248] Luciferase Assay
[0249] The 3′ UTR of the human PTEN and TIMP3 genes were PCR amplified using the following primers: PTEN Fw 5′-TCT AGA GAC TCT GAT CCA GAG AAT GAA CC-3′ [SEQ ID No:1] and PTEN Rw 5′-TCT AGA GTT GCC ACA AGT GCA AAG GGG TAG GAT GTG-3′ [SEQ ID No:2]; TIMP3 Fw 5′-TCT AGA CTG GGC AAA GAA GGG TCT TTC GCA AAG C-3′ [SEQ ID No:3] and TIMP3 Rw 5′ TCT AGA TTC CAA TAG GGA GGA GGC TGG AGG AGT CTC-3′ [SEQ ID No:4] and cloned downstream of the Renilla luciferase stop codon in pGL3 control vector (Promega), giving rise to the p3′UTR-PTEN and p3′UTR-TIMP3 plasmids.
[0250] These constructs were used to generate, by inverse PCR, the p3′-UTRmut-PTEN plasmid-primers: Fw: 5′-GTT GAA AAA AGG TTG GGG GCG GGT GTC ATG TAT ATA C-3 [SEQ ID No:5]; Rw: 5′-GTA TAT ACA TGA CAC CCG CCC CCA ACC TTT TTT CAA C-3′[SEQ ID No:6]; p3′-UTRmut-TIMP3 plasmid-primers: Fw: 5′-GTA TAA TTT AAA ATC ATT GGG CGG CGG GAG ACA CTT CTG TAT TTC-3′ [SEQ ID No:7]; Rw: 5′-GAA ATA CAG AAG TGT CTC CCG CCG CCC AAT GAT TTT AAA TTA TAC-3′ [SEQ ID No:8].
[0251] MeG01 cells were cotransfected with 1 μg of p3′UTR-PTEN or p3′UTR-TIMP3 and with p3′UTRmut-PTEN or p3′ UTR TIMP3 plasmids and 1 μg of a Renilla luciferase expression construct pRL-TK (Promega) by using Lipofectamine 2000 (Invitrogen). Cells were harvested 24 h post-transfection and assayed with Dual Luciferase Assay (Promega) according to the manufacturer's instructions. Three independent experiments were performed in triplicate.
[0252] Lung and Liver Cancer Samples and Cell Lines.
[0253] A total of 32 snap-frozen normal and malignant lung tissues (19 men and 13 women, median age: 70.0, range: 55-82) and 60 snap-frozen normal and 60 malignant liver tissues were collected at the Ohio State University Medical Center (Columbus, Ohio). Other 72 cancer and normal (24) lung tissues were purchased from US Biomax, Inc. All human tissues were obtained according to a protocol approved by the Ohio State Institutional Review Board.
[0254] In Vivo Experiments.
[0255] Animal studies were performed according to institutional guidelines. NCI-H460 cells were stable transfected by using shPTEN and TIMP3 plasmids (Santa Cruz); Calu-1 cells were stable transfected with shMET. After the selection in puromycin for 10 days 5 106 (H460) or 7106 (Calu-1) viable cells were injected s.c. into the right flanks of 6-wk-old male nude mice (Charles RiverBreeding Laboratories, Wilmington, Mass.). Treatment started five days (H460 xenograft) or ten days (Calu-1 xenograft) from tumor cell inoculation by daily ip injections of TRAIL/Apo2 (10 mg/kg/d) or vehicle (PBS) for two cycles of 5 days. Tumor size was assessed every five days by a digital caliper. The tumor volumes were determined by measuring the length (l) and the width (w) and calculating the volume (V=lw2/2). 35 days after injection, mice were sacrificed and tumors samples were analyzed by western blot for PTEN, TIMP3 and MET expression. Statistical significance between control and treated animals was evaluated by using Student's t test. Animal experiments were conducted after approval of the Institutional animal care and use committee, Ohio State University.
[0256] Statistical Analysis
[0257] Student's t-test and One-way ANOVA analysis was used to determine significance. All error bars represent the standard error of the mean. Pearson correlation coefficient was calculated to test the association between miR-221/miR-222 and PTEN in the classes Normal versus Tumor. Statistical significance for all the tests, assessed by calculating P-value, was <0.05.
[0258] Western Blot Analysis.
[0259] Total proteins from NSCLC and HCC cells were extracted with radioimmuno-precipitation assay (RIPA) buffer (0.15 mM NaCl, 0.05 mM Tris-HCl, pH 7.5, 1% Triton, 0.1% SDS, 0.1% sodium deoxycholate and 1% Nonidet P40). Sample extract (50 μg) was resolved on 7.5-12% SDS-polyacrylamide gels (PAGE) using a mini-gel apparatus (Bio-Rad Laboratories) and transferred to Hybond-C extra nitrocellulose. Membranes were blocked for 1 h with 5% nonfat dry milk in Tris-buffered saline containing 0.05% Tween 20, incubated overnight with primary antibody, washed and incubated with secondary antibody, and visualized by chemiluminescence. The following primary antibodies were used: anti-PTEN, anti-c-Jun, anti-p-c-Jun, anti-Fos, anti-p-JNK, anti-MMP3, anti-Mc1-1 (Santa Cruz), anti-TIMP3 (Millipore) anti-PI3K (BD Biosciences), anti-ERKs, anti-phospho ERKs, anti-AKT, anti-p-AKT, anti-GSK3b, anti-p-GSK3b (Ser9), anti-PAK1 anti-caspase-8,-3 and -9, anti-PARP, anti-cytochrome c (Cell signaling) and anti-MMP9, anti-FADD (Abcam), anti- -actin antibody (Sigma). A secondary anti-rabbit or anti-mouse immunoglobulin G (IgG) antibody peroxidase conjugate (Chemicon) was used.
[0260] Luciferase Assay.
[0261] DNA fragments containing the putative regulatory region upstream to miR-222/miR-221 (from +1˜−150 nt, +1˜−600, +1˜−1000 (+1 position corresponds to the 5′ terminus of miR-222 hairpin) were amplified and cloned in pGL3basic (Promega). Meg01 cells were transfected with Lipofectamine 2000 (Invitrogen), 1.0 g of pGL3basic empty vector or of pGL3 containing the above genomic fragments, 200 ng of Renilla luciferase expression construct pRL-TK (Promega) and MET, c-Jun, c-Fos siRNAs. After 48 h, 4 cells were lysed and assayed with Dual Luciferase Assay (Promega) according to the manufacturer's instructions. Three independent experiments were performed in triplicate. The primers utilized for the cloning were the followings: −1000pGL3b Forw: 5′ gctagccctagccaccttatcgaaaatagcattcc 3′ [SEQ ID No:9]; −600 pGL3b Forw: 5′ gctagcctgacatgctagtgagcacctgc 3′ [SEQ ID No:10]; −150 pGL3b Forw: 5′gctagcccagaggttgtttaaaattacgta 3′ [SEQ ID No:11]; miR-222 pGL3b Rev: 5′ctcgagagctgggtgatcctttgccttctg 3′ [SEQ ID No:12].
[0262] Real-Time PCR
[0263] Real-time PCR was performed using a standard TaqMan PCR Kit protocol on an Applied Biosystems 7900HT Sequence Detection System (Applied Biosystems). The 10 μl PCR reaction included 0.67 μl RT product, 1 μl TaqMan Universal PCR Master Mix (Applied Biosystems), 0.2 mM TaqMan probe, 1.5 mM forward primer and 0.7 mM reverse primer. The reactions were incubated in a 96-well plate at 95° C. for 10 min, followed by 40 cycles of 95° C. for 15 s and 60° C. for 1 min. All reactions were run in triplicate. The threshold cycle (CT) is defined as the fractional cycle number at which the fluorescence passes the fixed threshold. The comparative CT method for relative quantization of gene expression (Applied Biosystems) was used to determine miRNA expression levels. The y axis represents the 2(-CT), or the relative expression of the different miRs. miRs expression was calculated relative to U44 and U48 rRNA and multiplied by 104. Experiments were carried out in triplicate for each data point, and data analysis was performed by using software (Bio-Rad).
[0264] RNA Extraction and Northern Blotting
[0265] Total RNA was extracted with TRIzol solution (Invitrogen according to the manufacturer's instructions and the integrity of RNA was assessed with an Agilent BioAnalizer 2100 (Agilent, Palo Alto, Calif., USA). Northern blotting was performed as described by Calin et al., 2002. The oligonucleotides used as probes were the complementary sequences of the mature miRNA (miRNA registry):
[0000]
miR-221,
[SEQ ID No: 13]
5′-GAAACCCAGCAGACAATGTAGCT-3′,
miR-222,
[SEQ ID No: 14]
5′ GAGACCCAGTAGCCAGATGTAGCT-3′.
[0266] Antisense Inhibition of miRNA Expression.
[0267] 2′-O-methyl (2′-O-me) oligoribonucleotides were synthesized by Fidelity. The sequences of 2′-O-me-anti-miR-221 and 2′-O-me-anti-miR-222 are as follows:
[0000] [SEQ ID No: 15] 5′-gaaacccagcagacaauguagcu and [SEQ ID No: 16] 5′-gagacccagtagccagatgtagct.
2′-O-me-GFP miR (5′-aaggcaagcugacccugaagu [SEQ ID No:17]) was used as control. Cells were grown in six well plate (1.7×10 6 per well) for 24 h and transfected 100 nmoli/L/well of 2′-O-me-oligoribonucleotides using lipofectamine 2000. RNA and proteins were extracted after 72 h from the transfection.
[0268] Cell Death and Cell Proliferation Quantification
[0269] Cells were plated in 96-well plates in triplicate and incubated at 37° C. in a 5% CO 2 incubator. Super-Killer TRAIL (Alexis Biochemicals) was used for 24-48 h at 400 ng ml-1. Cell viability was examined with 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheniltetrazolium bromide (MTT)-Cell Titer 96 AQueous One Solution Cell Proliferation Assay (Promega), according to the manufacturer's protocol. Metabolically active cells were detected by adding 20 μl of MTT to each well. After 1 h of incubation, the plates were analyzed in a Multilabel Counter (Bio-Rad Laboratories). Apoptosis was assessed using Annexin V-FITC apoptosis detection kits followed by flowcytometric analysis and caspase 3/7 activity. Cells were seeded at 1.8106 cells per 100 mm dish, grown overnight in 10% FBS/RPMI, washed with phosphate-buffered saline (PBS) and then treated for 24 h with 400 ng/ml TRAIL. Following incubation, cells were washed with cold PBS and removed from the plates by trypsinization. The resuspended cells were washed with cold PBS and stained with FITC-conjugated annexin V antibody according to the manufacturer's instructions (Roche Applied Science). Cells (5×10 5 per sample) were then subjected to flow cytometric analysis. Flow cytometry analyses were done as described (Garofalo et al., 2007). The fraction of H460 cells treated with TRAIL was taken as the apoptotic cell population. The percentage of apoptosis indicated was corrected for background levels found in the corresponding untreated controls. Statistical analysis was done using two sample t test, assuming equal variance, and P value was calculated based on two-tailed test. For detection of caspase 3/7 activity, cells were cultured in 96-well plates and treated with TRAIL 400 ng/ml and analyzed using Caspase-Glo 3/7 Assay kit (Promega) according to the manufacturer's instructions. Continuous variables are expressed as mean values±standard deviation (s.d.).
[0270] Chromatin Immunoprecipitation.
[0271] Chromatin immunoprecipitation was performed as described by de Belle et al., 2000 with slight modifications. Cells (5106) from H460, Calu-1 and Snu-387 cell lines were fixed in 1% formaldehyde for 10 min at 37° C. Cells were washed with ice-cold 1 PBS, scraped in 1×PBS plus protease inhibitors, and collected by centrifugation. Cell pellets, resuspended in cell lysis buffer [50 mmol/L Tris-HCl (pH 8.0), 10 mmol/L EDTA, and 1% SDS] plus protease inhibitors, were then sonicated. DNA-protein complexes were immunoprecipitated using 5 g of the anti-c-Jun antibody (Santa Cruz) or with rabbit polyclonal IgG control (Zymed).
[0272] Cross-links in the immunoprecipitated chromatin were reversed by heating with proteinase K at 65° C. overnight, and DNA was purified by the MinElute Reaction Cleanup column (Qiagen) and resuspended in water. The purified chromatin was subjected to PCR and the products were analyzed by gel electrophoresis using 2% agarose. The following primers were used:
[0000]
Region1F:
[SEQ ID No: 18]
5′ GATGTGGAGAATAGATACCTTTGAG 3′
Region1R:
[SEQ ID No: 19]
5′ GGCACTGCCTACAAACCAGAGCATA 3′
Region2F:
[SEQ ID No: 20]
5′ GTCACTCAGTCAGTATCTGTTGGA 3′
Region2R:
[SEQ ID No: 21]
5′ GTGTGTAATTCAAGGTAAAGTTTTC 3′
[0273] Anti-PTEN and anti-TIMP3 siRNAs transfection.
[0274] Cells were cultured to 80% confluence and transiently transfected using Lipofectamine 2000 with 100 nM anti-PTEN or with 100 nM anti-TIMP3 SMARTpool siRNAs or control siRNAs (Dharmacon), a pool of four target specific 20-25 nt siRNAs designed to knock down gene expression.
[0275] miRNA locked nucleic acid in situ hybridization of formalin fixed, paraffin-embedded tissue section.
[0276] In situ hybridization (ISH) was carried out on deparaffinized human lung and liver tissues using previously published protocol (Nuovo et al., 2009), which includes a digestion in pepsin (1.3 mg/ml) for 30 minutes. The sequences of the probes containing the six dispersed locked nucleic acid (LNA) modified bases with digoxigenin conjugated to the 5′ end were:
[0000]
miR-221,
[SEQ ID No: 13]
5′-GAAACCCAGCAGACAATGTAGCT,
miR-222,
[SEQ ID No: 14]
5′ GAGACCCAGTAGCCAGATGTAGCT.
[0277] The probe cocktail and tissue miRNA were co-denatured at 60° C. for 5 minutes, followed by hybridization at 37° C. overnight and a low stringency wash in 0.2×SSC and 2% bovine serum albumin at 4° C. for 10 minutes. The probe-target complex was seen due to the action of alkaline phosphatase on the chromogen nitroblue tetrazolium and bromochloroindolyl phosphate (NBT/BCIP). Negative controls included the use of a probe which should yield a negative result in such tissues. No counterstain was used, to facilitate co-labeling for PTEN, TIMP3 and MET proteins. After in situ hybridization for the miRNAs, as previously described (Nuovo et al., 2009), the slides were analyzed for immunohistochemistry using the optimal conditions for PTEN (1:800, cell conditioning for 30 minutes), TIMP3 (1:1300, cell conditioning for 30 minutes) and MET (1:20, cell conditioning for 30 minutes). For the immunohistochemistry, the inventors used the Ultrasensitive Universal Fast Red system from Ventana Medical Systems. The inventors used normal liver and lung tissues as controls for these proteins. The percentage of tumor cells expressing PTEN, TIMP3 and miR-221 and miR-222 was then analyzed with emphasis on co-localization of the respective targets (miR-221 or miR-222 and either PTEN or TIMP3).
[0278] Materials.
[0279] Media, sera and antibiotics for cell culture were from Life Technologies, Inc. (Grand Island, N.Y., USA). Protein electrophoresis reagents were from Bio-Rad Laboratories (Richmond, Va., USA) and western blotting and ECL reagents from GE Healthcare (Piscataway, N.J., USA). All other chemicals were from Sigma (St Louis, Mo., USA).
[0280] Lung and Liver Cancer Samples and Cell Lines.
[0281] Human Calu-1 and A549 cell lines were grown in Dulbecco's modified Eagle's medium containing 10% heat-inactivated fetal bovine serum (FBS) and with 2 mM L-glutamine and 100 Uml-1 penicillin-streptomycin. He1299, H460, A459, H1975, H1299, H1573, H23, PLCRF15, SNU-387, Snu-423, Snu-475 cell lines were grown in RPMI containing 10% heat-inactivated FBS and with 2 mM L-glutamine and 100 Uml-1 penicillin-streptomycin. Sk-hep1, Hep-G2, HepG2C3A, Hep3B, Huh7 were grown in MEM supplemented with 10% fetal bovine serum, 2 mM L-glutamine and 100 Uml-1 penicillin-streptomycin. Normal Hepatocytes were grown in Hepatocytes growth medium (ScienceII) supplemented with 10% fetal bovine serum, 2 mM L-glutamine, 1% of hepatocyte growth supplement (HGS) and 100 Uml-1 penicillin-streptomycin.
[0282] Migration Assay
[0283] Transwell insert chambers with 8-nm porous membrane (Greiner bio-one) were used for the assay. Cells were washed three times with PBS and added to the top chamber in serum-free media. The bottom chamber was filled with media containing 10% FBS. Cells were incubated for 24 h at 37° C. in a 5% CO2 humidified incubator. To quantify migrating cells, cells on the top chamber were removed by using a cotton-tipped swab, and the migrated cells were fixed in PBS, 25% glutaraldehyde and stained with Crystal Violet stain, visualized under a phase-contrast microscope, and photographed. Cristal violet-stained cells were moreover solubilized in acetic acid and methanol (1:1) and absorbance was measured at 595 nm. The results are means of three independent experiments ±S.D.
[0284] Invasion Assay
[0285] H460 and SK-Hep-1 cells were placed into the top chamber of a BD Falcon HTS FluoroBlok insert with a membrane containing 8-nm pores (BD Biosciences) in 300 L of serum-free Dulbecco's modified Eagle medium in triplicate. The inserts were placed into the bottom chamber wells of a 24-well plate containing Dulbecco's modified Eagle medium media and fetal bovine serum (10%) as chemoattractant. Cells that migrated through the pores of the membrane to the bottom chamber were labeled with 8 g/mL calcein-AM (Molecular Probes, Eugene, Oreg.) in phosphate-buffered saline (PBS) for 30 minutes at 37° C. The fluorescence of migrated cells was quantified using a fluorometer at excitation wavelengths of 485 nm and emission wavelengths of 530 nm and expressed as arbitrary fluorescence units. Data are expressed as mean±standard error of 4 separate determinations.
[0286] PTEN and TIMP3 Plasmids.
[0287] PTEN and TIMP3 cDNAs were obtained from H460 cells RNA by using the one step RT-PCR kit (Invitrogen) according to the manufacturer's instructions. The PCR fragments were amplified by using the following primers:
[0000]
NotI-TIMP3-HA:
[SEQ ID No: 22]
5′ gcggccgcatgaccccttggctcgggctcatcgtgct 3′
BglII-TIMP3-HA:
[SEQ ID No: 23]
5′ agatctcagggtctggcgctcaggggtctgt 3′
NotI-PTEN-HA:
[SEQ ID No: 24]
5′ gcggccgcatgacagccatcatcaaagagatcgttag 3′
XbaI-PTEN-HA:
[SEQ ID No: 25]
5′ tctagaggtgttttatccctcttgataaaaaaaaattca 3′
[0288] and then cloned in pCRUZ-HA (Santa Cruz) after digestion with NotI-XbaI (PTEN) or NotI-BglII (TIMP3). All vectors were controlled by sequencing.
[0289] Target Analysis
[0290] Bioinformatic analysis was performed by using these specific programs: Targetscan1, Pictar2 and RNhybrid3. 1 http://www.targetscan.org/ 2 http://pictar.bio.nyu.edu/ 3 http://bibiserv.techfak.uni-bielefeld.de/
Example VII
Method of Treating HCC in Patients Exhibiting TRAIL Sensitive TRAIL Expression Pattern in HCC Tumor Samples
[0291] This example describes a method of selecting and treating HCC patients that are likely to have a favorable response to TRAIL treatment as a therapy.
[0292] For some HCC patients, TRAIL therapy can prolong survival (Sun et al., J. Cancer Res. Clin. Oncol. 132(7):458-465, 2006). However, it would be beneficial to identify patients that are most likely to benefit from TRAIL therapy prior to initiating treatment.
[0293] It is now disclosed herein that the prognosis of HCC patients expressing TRAIL sensitive TRAIL Expression Pattern in tumor samples relative to a control (such as non-cancerous liver tissue obtained from the same patient) significantly improves after treatment with TRAIL. In contrast, patients expressing TRAIL resistant TRAIL Expression Pattern in tumor samples do not exhibit a significant increase in survival following TRAIL treatment and thus are not good candidates for such adjunctive treatment.
[0294] A patient diagnosed with HCC first undergoes liver resection with an intent to cure. HCC tumor and non-cancerous tissue samples are obtained from the portion of the liver tissue removed from the patient. RNA is then isolated from the tissue samples using any appropriate method for extraction of small RNAs that are well known in the art, such as by using TRIZOL™. Purified RNA is then subjected to RT-PCR using primers specific for c-Jun and miR-221 and miR-222, optionally in conjunction with PTEN and/or TIMP3. The assay may also be run with miR-221 and miR-222 and PTEN and/or TIMP3, without c-Jun. These assays are run to determine the expression level of the pertinent RNA in the tumor and non-cancerous tissues. If TRAIL sensitive Expression Pattern is found in the tumor tissue relative to the non-cancerous tissue, the patient is a candidate for TRAIL adjunctive therapy.
[0295] Accordingly, the patient is treated with a therapeutically effective amount of TRAIL a according to methods known in the art. The dose and dosing regimen of TRAIL will vary depending on a variety of factors, such as health status of the patient and the stage of the HCC. Typically, TRAIL is administered in many doses over time.
Example VIII
Alternative Treatment Method for HCC Patients with Low Expression of miR-26
[0296] This example describes a method of treating a patient diagnosed with HCC in the absence of liver resection. To determine whether a patient diagnosed with HCC is a good candidate for TRAIL therapy, a HCC tumor sample is obtained from the patient that has not undergone liver resection, along with a non-cancerous liver tissue sample. The tissue samples can be obtained according to any method known in the art. For example, the tissue samples can be obtained by performing a biopsy procedure using a hypodermic needle to remove the desired tissues.
[0297] RNA is then isolated from the tissue samples using any appropriate method for extraction of small RNAs that are well known in the art, such as by using TRIZOL™. Purified RNA is then subjected to RT-PCR using primers specific for miR-26 to determine the expression level of miR-26 in the tumor and non-cancerous tissues. If TRAIL sensitive TRAIL Expression Pattern is found in the tumor tissue relative to the non-cancerous tissue, the patient is a candidate for therapy.
[0298] Accordingly, the patient is treated with a therapeutically effective amount of therapeutic according to methods known in the art. The dose and dosing regimen will vary depending on a variety of factors, such as health status of the patient and the stage of the HCC. Typically, treatment is administered in many doses over time.
Example IV
Method of Treating HCC in Patients Exhibiting TRAIL Resistant TRAIL Expression Pattern in HCC Tumor Samples
[0299] This example describes a method of treating a patient diagnosed with HCC if the patient exhibits a TRAIL resistant TRAIL Expression Pattern in the HCC tumor.
[0300] A patient diagnosed with HCC first undergoes liver resection with an intent to cure. HCC tumor and non-cancerous tissue samples are obtained from the portion of the liver tissue removed from the patient. RNA is then isolated from the tissue samples using any appropriate method for extraction of small RNAs that are well known in the art, such as by using TRIZOL™. Purified RNA is then subjected to RT-PCR using primers specific for miR-26 to determine the expression level of miR-26 in the tumor and non-cancerous tissues. If TRAIL resistant TRAIL Expression Pattern is found in the tumor tissue relative to the non-cancerous tissue, the patient is unlikely to respond favorably to TRAIL adjunctive therapy. Accordingly, the patient does not receive TRAIL therapy but is considered for other treatment modalities to convert to TRAIL sensitivity. Alternatively, the patient is monitored for post-operative signs of disease recurrence.
Example IX
Methods of Diagnosing HCC Patients
[0301] In one particular aspect, there is provided herein a method of diagnosing whether a subject has, or is at risk for developing, hepatocellular carcinoma (HCC). The method generally includes measuring the TRAIL Expression Pattern in a test sample from the subject and determining whether the TRAIL Expression Pattern in the test sample deviates relative to the level of a TRAIL Expression Pattern in a control sample, is indicative of the subject either having, or being at risk for developing, HCC. In certain embodiments, the level of the at least one gene product is measured using Northern blot analysis. Also, in certain embodiments, the level of the at least one gene product in the test sample is less than the level of the corresponding miR gene product in the control sample, and/or the level of the at least one miR gene product in the test sample is greater than the level of the corresponding miR gene product in the control sample.
Example X
Measuring miR Gene Products
[0302] The level of the at least one miR gene product can be measured by reverse transcribing RNA from a test sample obtained from the subject to provide a set of target oligodeoxynucleotides; hybridizing the target oligodeoxynucleotides to a microarray comprising miRNA-specific probe oligonucleotides to provide a hybridization profile for the test sample; and, comparing the test sample hybridization profile to a hybridization profile generated from a control sample. An alteration in the signal of at least one miRNA is indicative of the subject either having, or being at risk for developing, HCC.
Example XI
Diagnostic and Therapeutic Applications
[0303] In another aspect, there is provided herein are methods of treating HCC in a subject, where the signal of at least one miRNA, relative to the signal generated from the control sample, is de-regulated (e.g., down-regulated and/or up-regulated).
[0304] Also provided herein are methods of diagnosing whether a subject has, or is at risk for developing, a HCC associated with one or more adverse prognostic markers in a subject, by reverse transcribing RNA from a test sample obtained from the subject to provide a set of target oligodeoxynucleotides; hybridizing the target oligodeoxynucleotides to a microarray comprising miRNA-specific probe oligonucleotides to provide a hybridization profile for the test sample; and, comparing the test sample hybridization profile to a hybridization profile generated from a control sample. An alteration in the signal is indicative of the subject either having, or being at risk for developing, the cancer.
[0305] Also provided herein are methods of treating HCC in a subject who has HCC in which at least two gene products of the TRAIL Expression Pattern genes are down-regulated or up-regulated in the cancer cells of the subject relative to control cells. When the at least two gene products are down-regulated in the cancer cells, the method comprises administering to the subject an effective amount of at least two isolated gene products, such that proliferation of cancer cells in the subject is inhibited. When two or more gene products are up-regulated in the cancer cells, the method comprises administering to the subject an effective amount of at least one compound for inhibiting expression of at least one gene product, such that proliferation of cancer cells in the subject is inhibited. Also provided herein are methods of treating HCC in a subject, comprising: determining the amount of at least two TRAIL Expression gene products in HCC cells, relative to control cells; and, altering the amount of the gene products expressed in the HCC cells by: administering to the subject an effective amount of at the at least two gene products, if the amount of the gene products expressed in the cancer cells is less than the amount of the gene products expressed in control cells; or administering to the subject an effective amount of at least one compound for inhibiting expression of the at least two gene products, if the amount of the gene product expressed in the cancer cells is greater than the amount of the gene product expressed in control cells, such that proliferation of cancer cells in the subject is inhibited.
Example XII
Compositions
[0306] Also provided herein are pharmaceutical compositions for treating TRAIL resistant cancer, comprising at least two isolated TRAIL Expression Pattern gene product and a pharmaceutically-acceptable carrier. In a particular embodiment, the pharmaceutical compositions comprise gene products corresponds to gene products that are down-regulated in HCC cells relative to suitable control cells.
[0307] In another particular embodiment, the pharmaceutical composition comprises at least one expression regulator (for example, an inhibitor) compound and a pharmaceutically-acceptable carrier.
[0308] Also provided herein are pharmaceutical compositions that include at least one expression regulator compound that is specific for a gene product that is up- or down-regulated in HCC cells relative to suitable control cells.
Example XIII
Kits
[0309] Any of the compositions described herein may be comprised in a kit. In a non-limiting example, reagents for isolating miRNA, labeling miRNA, and/or evaluating an miRNA population using an array are included in a kit. The kit may further include reagents for creating or synthesizing miRNA probes. The kits will thus comprise, in suitable container means, an enzyme for labeling the miRNA by incorporating labeled nucleotide or unlabeled nucleotides that are subsequently labeled. It may also include one or more buffers, such as reaction buffer, labeling buffer, washing buffer, or a hybridization buffer, compounds for preparing the miRNA probes, and components for isolating miRNA. Other kits may include components for making a nucleic acid array comprising oligonucleotides complementary to miRNAs, and thus, may include, for example, a solid support.
[0310] For any kit embodiment, including an array, there can be nucleic acid molecules that contain a sequence that is identical or complementary to all or part of any of the sequences herein.
[0311] The components of the kits may be packaged either in aqueous media or in lyophilized form. The container means of the kits will generally include at least one vial, test tube, flask, bottle, syringe or other container means, into which a component may be placed, and preferably, suitably aliquoted. Where there is more than one component in the kit (labeling reagent and label may be packaged together), the kit also will generally contain a second, third or other additional container into which the additional components may be separately placed. However, various combinations of components may be comprised in a vial. The kits of the present invention also will typically include a means for containing the nucleic acids, and any other reagent containers in close confinement for commercial sale. Such containers may include injection or blow-molded plastic containers into which the desired vials are retained.
[0312] When the components of the kit are provided in one and/or more liquid solutions, the liquid solution is an aqueous solution, with a sterile aqueous solution being one preferred solution. Other solutions that may be included in a kit are those solutions involved in isolating and/or enriching miRNA from a mixed sample.
[0313] However, the components of the kit may be provided as dried powder(s). When reagents and/or components are provided as a dry powder, the powder can be reconstituted by the addition of a suitable solvent. It is envisioned that the solvent may also be provided in another container means. The kits may also include components that facilitate isolation of the labeled miRNA. It may also include components that preserve or maintain the miRNA or that protect against its degradation. The components may be RNAse-free or protect against RNAses.
[0314] Also, the kits can generally comprise, in suitable means, distinct containers for each individual reagent or solution. The kit can also include instructions for employing the kit components as well the use of any other reagent not included in the kit. Instructions may include variations that can be implemented. It is contemplated that such reagents are embodiments of kits of the invention. Also, the kits are not limited to the particular items identified above and may include any reagent used for the manipulation or characterization of miRNA.
[0315] It is also contemplated that any embodiment discussed in the context of an miRNA array may be employed more generally in screening or profiling methods or kits of the invention. In other words, any embodiments describing what may be included in a particular array can be practiced in the context of miRNA profiling more generally and need not involve an array per se.
[0316] It is also contemplated that any kit, array or other detection technique or tool, or any method can involve profiling for any of these miRNAs. Also, it is contemplated that any embodiment discussed in the context of an miRNA array can be implemented with or without the array format in methods of the invention; in other words, any miRNA in an miRNA array may be screened or evaluated in any method of the invention according to any techniques known to those of skill in the art. The array format is not required for the screening and diagnostic methods to be implemented.
[0317] The kits for using miRNA arrays for therapeutic, prognostic, or diagnostic applications and such uses are contemplated by the inventors herein. The kits can include an miRNA array, as well as information regarding a standard or normalized miRNA profile for the miRNAs on the array. Also, in certain embodiments, control RNA or DNA can be included in the kit. The control RNA can be miRNA that can be used as a positive control for labeling and/or array analysis.
[0318] The methods and kits of the current teachings have been described broadly and generically herein. Each of the narrower species and sub-generic groupings falling within the generic disclosure also form part of the current teachings. This includes the generic description of the current teachings with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.
Example XIV
Array Preparation and Screening
[0319] Also provided herein are the preparation and use of miRNA arrays, which are ordered macroarrays or microarrays of nucleic acid molecules (probes) that are fully or nearly complementary or identical to a plurality of miRNA molecules or precursor miRNA molecules and that are positioned on a support material in a spatially separated organization. Macroarrays are typically sheets of nitrocellulose or nylon upon which probes have been spotted. Microarrays position the nucleic acid probes more densely such that up to 10,000 nucleic acid molecules can be fit into a region typically 1 to 4 square centimeters.
[0320] Microarrays can be fabricated by spotting nucleic acid molecules, e.g., genes, oligonucleotides, etc., onto substrates or fabricating oligonucleotide sequences in situ on a substrate. Spotted or fabricated nucleic acid molecules can be applied in a high density matrix pattern of up to about 30 non-identical nucleic acid molecules per square centimeter or higher, e.g. up to about 100 or even 1000 per square centimeter. Microarrays typically use coated glass as the solid support, in contrast to the nitrocellulose-based material of filter arrays. By having an ordered array of miRNA-complementing nucleic acid samples, the position of each sample can be tracked and linked to the original sample.
[0321] A variety of different array devices in which a plurality of distinct nucleic acid probes are stably associated with the surface of a solid support are known to those of skill in the art. Useful substrates for arrays include nylon, glass and silicon. The arrays may vary in a number of different ways, including average probe length, sequence or types of probes, nature of bond between the probe and the array surface, e.g. covalent or non-covalent, and the like. The labeling and screening methods described herein and the arrays are not limited in its utility with respect to any parameter except that the probes detect miRNA; consequently, methods and compositions may be used with a variety of different types of miRNA arrays.
[0322] In view of the many possible embodiments to which the principles of our invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as a limitation on the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.
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It is disclosed herein that miR-221 and miR-222 down-regulate PTEN and TIMP3 tumor suppressors, resulting in TRAIL resistance. The present invention provides research, diagnostic, and therapeutic tools and methods related to this discovery. Diagnostics, prognostics and treatments for human hepatocellular cancer and non-small cell lung carcinoma having a TRAIL resistance are particularly described herein.
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CROSS-REFERENCE TO RELATED APPLICATIONS
The invention relates to a further improvement or further provision of a positional fixing of a tab on a sheet metal lid according to the simultaneously filed (co-pending) PCT application No. PCT/DE2002/004283, originating from the same inventors and the same legal successors, the disclosure of said application being incorporated by reference herein. The corresponding U.S. application is Ser. No. 10/541,845, published as US 2007/0062950.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of shaping a portion of a sheet metal lid of a beverage can, the lid including a panel having an openable area defined by a score line in the panel, and a mounting place for attaching a tab for breaking into the openable area.
2. Description of Background and Relevant Information
When the tab is in an attached condition to the sheet metal lid, it is known by the expect as a SOT (Stay on Tab), which is provided for opening an openable area in the surface of a lid (usually designated as a “panel”). For this purpose, the tab is taken at a grip end and raised with a vertical tilting motion for breaking open an openable area along a line of weakness (usually called a “score line”) with its opening end.
Particularly when large opening ends (LOE) are used for the openable area, difficulties are encountered in the related art to when fixing the positions of the tab in an attached condition to the sheet metal lid. Suggestions on this topic have already been made, for example, in U.S. Pat. No. 5,799,816 (Schubert). In this document, an opening of an attaching portion of the tab is proposed, which attaching portion is usually designated as a “rivet island”. The attaching portion is secured to the panel of the sheet metal lid through a shaped rivet and overlaps a round to elongated reformed bead with an opening provided in the attaching portion. The bead may also be formed after attaching the tab, compare column 3, lines 63-67, column 5, lines 37-44, claim 3 of Schubert and the associated graphical illustration in FIGS. 2 and 4 thereof.
SUMMARY OF THE INVENTION
The invention addresses the technical problem of achieving the aforementioned effect, but with an improved manufacture and reliability of the anti-rotation block and with an improved positional alignment of the tab in the attached condition. For this purpose, a method is proposed.
Advantageously, an already present peripheral edge on a usual tab is used, the edge not having to be specifically formed additionally for obtaining the rotation barrier after the attachment of the tab to the panel (commonly referred to as “staking”). The only manipulation is effected on the sheet metal lid itself, which is provided with a shape or molding, as the rivet is in a preliminary phase, which shape or molding may preferably also be pre-formed in parallel together with the formation of the rivet and subsequently be modified in shape, or more precisely “reformed”, in a further processing step of the sheet metal lid being manufactured. The projection can thus be formed integrally with the sheet metal lid, as is the securing point is formed by one-piece manufacturing for the attaching portion of the tab.
The projection does not protrude through an opening of the attaching portion, and the attaching portion is not provided with an opening beforehand, but the attaching portion remains entire and a blocking means that acts on the attaching portion from an outside is provided, as disclosed in the aforementioned PCT application and the aforementioned US 2007/0062950.
Forming at least one projection to have an asymmetrical cross section is particularly advantageous, such projection having a steeper side facing the attaching portion than the side facing away from the attaching portion. Such a shape may also be selected for punctiform or oval projections.
In a subsequent reshaping, reforming, or post-forming, the thickness of a top side of the (strip-shaped) projection is reduced. Thereby, a solidification of the portion and the projection as a whole is achieved. This also applies to the method. The score line can be introduced not simultaneously with the reforming, in temporally shifted or offset processing steps. The same is valid for the pre-forming of the bead, which is not shaped at the same time, as the score line is introduced.
In order to obtain the blocking effect, which can also be a limiting effect, which is to be understood to range from a complete prevention of a rotating movement up to a substantial limitation of the rotating movement, an outer edge of the flat attaching portion (i.e., the rivet island) is stopped by abutting against the projection that is shaped to protrude out of the sheet metal lid.
The projection can have a strip shape (i.e., a line shape) and be preferably oriented one of transversely and in parallel to a longitudinal extension of the tab (longitudinal axis or longitudinal plane), the projection engaging at a correspondingly oriented peripheral edge of the attaching portion for its blocking effect or being provided very closely adjacent thereto. In a longitudinal extension, the projection can extend over more than 30%, preferably over more than 50% to more than 80% of the width of the attaching portion.
Several projections can be provided, not all projections having to be associated with the same outer edge portion of the attaching portion. The projections can also be differently shaped, i.e., strip-shaped, round to oval, or a combination thereof. If a straight-lined outer edge portion of the attaching portion is provided, a straight-lined (strip-shaped) embodiment of the projections can be advantageous. The straight-lined or linear strip embodiment can also be achieved by arranging at least two punctiform projections in a line, which then form a group that is associated with the same outer edge portion of the attaching portion.
When several projections are provided in the aforementioned sense, they do not have to engage the same edge line of the attaching portion when starting a rotating movement, but instead they can be assigned to different outer edges.
When providing a strip-shaped projection, it can be designed to have a length longer than the diameter of the finished rivet head.
The attaching portion being formed from a piece of the central portion of the tab, only minor gaps are visible between the attaching portion, which is displaced downwards to a lower plane by a double buckling line, and the somewhat higher, parallel plane of the remaining tab. Accordingly, the mounting of the projections on at least one of the free peripheral edges facing outward from the attaching portion is barely or only hardly visible from the outside, so that the rotation blocking is virtually invisible to the observer. A colored tab is not changed further in its colored appearance.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments explain and supplement the following detailed description of the invention, wherein further reference is made to the content of the disclosure of the aforementioned PCT application and US publication. The invention is further described in the detailed description, in which like reference numerals represent similar parts throughout the views of the drawings, and wherein:
FIGS. 1 , 2 , and 3 show three stages in a manufacturing process of a sheet metal lid, comprising a station for inserting a score line or a weakening line 16 , a station for introducing a finger depression 13 and additional beads 18 a in the openable area inside the score/weakening line, and a first station at which a pre-form 19 of a bead 20 is shaped, achieving a blockage of the rotational behavior of a tab 30 ;
FIGS. 4 and 5 show a further, subsequent manufacturing station, at which a tab 30 is mounted over a rivet 11 integrally formed on the sheet metal lid, via an attaching portion 31 , which as a flat attachment tongue (rivet island) serves for mounting (“staking”);
FIG. 6 is a sectional view, taken along line 6 - 6 of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
The sheet metal lid obtained according to a method as shown in FIGS. 1 to 3 has a visible edge portion 12 as a seamable edge that is suitable for seaming to a body of a beverage can. The sheet metal lid itself is produced from thin sheet metal, typically less than 0.24 mm, and has already passed through preceding workstations before reaching the stage shown in FIG. 1 . The lid comprises an inner surface portion (panel) 10 surrounded by a seamable edge 12 . Within the panel 10 , a weakening line 16 is to be introduced around an openable area, the openable area being surrounded by a substantially U-shaped bead 18 . Within the bead, which opens in the center portion of the panel, a substantially oval weakening line 16 is to be designed as a score line having a transitional section that is not scored and thus serves as a connecting portion to the rest of panel 10 when the openable area 17 is broken in along the score line 16 by the effect of a tab, which is explained below. This is illustrated in FIG. 2 .
FIG. 5 shows a mounting place 11 provided approximately in the middle of the panel 10 . An attaching portion 31 as a sheet metal tongue is schematically associated therewith, the attaching portion 31 being part of the tab according to FIG. 4 , on which it is formed integrally via an articulation line as a buckling line 38 . The tab 30 comprises a grip portion 32 , provided here with a circular opening, at which the tab is operated by the user for breaking open the score line 16 according to FIG. 2 . The tab 30 also comprises an opening nose portion 33 before the attaching portion 31 , the opening portion being located as a break-in nose above the openable area 17 , for which purpose an additional, eyeball-shaped bead 18 a as shown in FIG. 3 is provided in a separate working step, the bead reinforcing the transverse LOE openable area, for being able to apply the opening forces to the break-open starting portion (loop-shaped end of the score line 16 ). The mounted tab 30 is substantially parallel to the panel 10 , which itself does not have to be designed exactly in one plane, but may be slightly bulged, though the area around the mounting place 11 is substantially planar, or flat, allowing a substantially parallel arrangement of the attaching tongue 31 of the tab 30 .
As shown in the figures, at least one of the three strip-shaped projections 20 , 21 a, 21 b (see FIGS. 5 , 6 ) is re-formed around the area for the mounting place 11 as upwardly protruding beads (i.e., towards the outside of the sheet metal lid). The bead 20 , extending transversely to a midplane 100 , is longer than the two neighboring beads 21 a, 21 b, which extend parallel to the midplane 100 .
At one manufacturing station, the re-forming of the three beads 20 (or also 21 a, 21 b ) is improved or designed more exactly. The “re-forming” results in a formation of the beads (projections) as used later for the positional fixing, according to FIG. 3 and as shown in various ones of the drawing figures of the aforementioned US 2007/0062950. At the station, the at least one projection receives its correct profile geometry, after having been re-formed integrally from the sheet metal lid (the panel) according to FIG. 1 . As mentioned in the Summary above, forming at least one projection to have an asymmetrical cross section is particularly advantageous, such projection having a steeper side 21 a ' and 21 b ' facing the attaching portion 31 than the side (such as 21 b ”) facing away from the attaching portion. Such a shape may also be selected for punctiform or oval projections.
As more particularly described in the aforementioned US 2007/0062950, reference being made below to drawings and reference numerals thereof, a re-forming step comprises a shaping of the pre-form 19 with a coining operation (i.e., an embossing operation) for further flattening the top surface 20 c. In the re-forming process, the tool is applied likewise from the top and from the bottom for the re-forming. The slight bend according to FIG. 8 a of the aforementioned US 2007/0062950 that is detectable on the left in the rising side of the pre-form 19 can be recognized in the final form illustrated in FIG. 8 a of the aforementioned US 2007/0062950, the way in which the sharp front edge 20 ″ is introduced in the initially gently rising left incline of the shaped pre-form 19 also being visible. To the right of the transverse plane 101 , the second incline of the pre-form is shaped from bottom to top, for forming a flat top side 20 c starting approximately at the instep of the pre-form 19 , the top side, in a portion 20 b, leading gently over to the rest of the sheet metal panel 10 .
Additionally, in the final form, the attaching portion 31 , which is mounted at the rivet 11 , and also the tab 30 are already attached according to FIG. 4 , also in a sectional view. The tab is arranged with its intermediate web between the left opening and the grip opening 32 b, substantially above the transversely extending projection 20 . The two openings of the tab are shown in FIG. 4 , one opening resulting from the formation of the attaching portion 31 , which is further connected to the tab 30 via an articulation line 38 , whereas the opening for inserting a finger is designed particularly. The opening 32 b forms part of the grip portion 32 , the web 32 a between the two openings being shown slightly bulged in FIG. 8 a of the aforementioned US 2007/0062950, having a front edge 32 c that was related to the free edge 31 c of the attaching portion 31 during manufacture. A major part of the projection 20 is thus located below the web and is barely visible from outside.
In this context, a modified sequence of the two-stage re-forming can be performed besides the processing sequence according to FIGS. 1 to 3 herein or in the aforementioned US 2007/0062950, for example an initial introduction of the at least one pre-form, as illustrated by the pre-form 19 in the top picture of FIG. 8 a of US 2007/0062950, in a first working step, still without the introduction of score lines (as weakening lines), of which weakening line 16 is an example. For a projection 20 with a related pre-form 19 , this is illustrated by the sequence of FIGS. 1 , 2 , and 3 ; the subsequent assembly can be identical to that illustrated in FIG. 4 .
If multiple projections are used for blocking rotating movements of the tab—all pre-forms 19 are shaped according to FIG. 1 . In the figure, only one projection is illustrated. The first score line is introduced only later, in a separate working step, e.g., after re-forming (further shaping) of the pre-shaped projection 19 . Here, the one projection receives its correct, assigned profile, as is shown in the bottom illustration of FIG. 8 a of US 2007/0062950. In this way, it can be realized that a scoring operation, subjecting the sheet metal to severe stresses, is not performed at the same time as the shaping of the pre-form takes place in the first working step, the shaping considerably stressing the sheet metal lid. The score line can be introduced prior to or after the re-forming operation which also stresses the sheet metal. During re-forming—as shown in FIG. 8 a —the wall thickness on the top side of the projection is reduced by about 10% to 15%, with a simultaneously occurring compression and solidification of the portion, which is achieved by the embossing operation (coining) uniformly from the top and from the bottom.
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The invention relates to a method for forming a sheet metal lid. At least one projection is formed twice. First, the projection is shaped from a panel of the sheet metal lid, the pre-form being located near an attaching portion of a tab, but at a distance from the mounting place. Second, at least a front edge of the pre-form of the at least one projection is re-formed. No score line is provided in the panel, neither during shaping, nor during re-forming. An improved blocking for an outer edge portion of the attaching portion is thus obtained, the outer edge portion being associated with the front edge.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a 371 of PCT/IB2013/059572, filed Oct. 23, 2013 which, in turn, claimed the priority of Italian Patent Application No. F12012A000232 filed on Oct. 29, 2012, both applications are incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
The present invention concerns the field of graphic apparatuses and in particular its object is an apparatus and a relative method for the so-called “weeding” of plastic or paper films having or more self-adhesive, double sided adhesive or electrostatic layers coupled with a support liner treated with a non-stick agent.
BACKGROUND OF THE INVENTION
In the preparation of adhesive graphics, simply decorative or also having a protective function, obtained through various printing or through simple engraving processes, a distribution of single graphics is obtained on a single sheet comprising films of the type indicated above, printed and/or cut, coupled with a supporting silicone release paper, or liner. A cutting machine thus has the function of cutting the fringes of the various programmed drawings or writings only on the film, without however cutting also the support/release paper. At this stage there is the need of removing the “weeds”, that is, the parts of adhesive film which are not processed and are therefore outside the graphics. In fact, the subsequent user, for his production requirements, needs to have a sheet in which there are only the graphics on the support paper, so that the same graphics can be easily removed and applied as desired.
Such a removal operation of the superfluous film, on the whole also called “weed” for the sake of simplicity, is in fact called weeding. This is a very onerous operation and at the same time delicate since, especially when the contours of the graphics have irregular shapes, or in any case they have indentations or acute curves or undercuts (situation which occurs even with simple alphanumerical characters), the film of weed to be removed tends to tear, leaving residues, or to pull away also the graphical part that should instead be left unaltered. There are also often small parts, typically the internal hollows of characters and writings in general, which require operations that are accurate, precise and repeated.
Such an operation is currently carried out in a completely manual manner, with serious affection of the production time and on labor costs. Automation of the weeding process, despite the attempts made, has been found to be problematic, indeed for the difficulties mentioned above, furthermore enhanced by the fact that the different graphics to be treated and their distribution demand requirements that are always different.
SUMMARY OF THE INVENTION
The present invention, on the other hand, provides a response to this strongly felt need, by providing a series of surprisingly effective technical expedients that make possible to achieve a weeding system that obtains a fully effective result, capable of replacing the manual methods currently in use, with consequent remarkable advantages.
The essential features of a rough weeding device according to the invention are defined in annexed claim 1 . Other advantageous features, in connection with preferred or in any case effective embodiments, are the subject of the different dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Characteristics and advantages of the rough weeding device according to the present invention will become apparent from the following description of embodiments thereof, made purely by way of example and not limitative, with reference to the attached drawings in which:
FIG. 1 is a schematic axonometric view of an apparatus comprising a rough weeding device according to the invention;
FIG. 2 is a top plan view of the apparatus;
FIG. 3 is an axonometric view from below of a gripper of a fine weeding device of the apparatus;
FIG. 4 is a sectional view taken along a longitudinal plane of the apparatus of a seizing head of a rough weeding device according to the invention;
FIG. 5 and FIG. 6 represent, respectively in an axonometric and a side view, a cutting device used in the apparatus according to the invention;
FIGS. 7 and 8 are, respectively, a front view and a top plan view of a blower of the rough weeding head of FIG. 4 ;
FIGS. from 9 to 11 are cross-section views of the blower in the previous figures, taken respectively along the lines IX, X e XI of FIG. 7 ;
FIG. 12 is a further representation, in this case partial, schematic, broken and axonometric, of the rough weeding head; and
FIGS. from 13 a to 13 l represent schematically respective subsequent stages of the rough weeding process;
FIG. 14 is a side view of the device according to a different embodiment of the invention;
FIG. 15 is an enlarged representation, but mirrored, of the area inside the circle XV of FIG. 14 ;
FIG. 16 is an axonometric view of substantially the same component (seizing head) shown in FIG. 15 ; and
FIG. 17 represents in isolation and in axonometric view weed collection unit in accordance with the second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to said figures, an apparatus according to the invention is intended to automatically remove the weed, which advantageously undergoes a pre-emptive cutting operation, with suitably positioned assisting cuts that are added to the conventional ones that define the periphery/outline of the various graphic elements. The cuts, carried out with conventional plotters, in turn have the characteristic of cutting the self-adhesive, adhesive or electrostatic, plastic or paper film, without affecting the support paper or liner. The present invention concerns the actual weeding apparatus, per se provided with novel and advantageous structural and functional characteristics.
The apparatus comprises a frame 1 equipped with a top plane 1 a on which through known pneumatic systems the sheets of material to be weeded are fed and moved forward. Upstream of the plane there is arranged a feeder 2 , advantageously having a lifting surface, with a motorised control, on which to position the sheets with dimensions that can vary from 200×300 mm to 1000×1400 mm or also reels having corresponding size. The plane 2 a of the feeder can comprise, along two consecutive sides, mechanical abutments that are suitable for allowing a reference of the sides of the sheet, the so-called “print register” sides. This, along with the control of the height of the plane, ensures that when a stack of sheets is arranged on the plane, the sheet on top, intended to be processed, is always positioned perfectly with respect to the work plane 1 a of the frame 1 .
A first part of the plane 1 a , taking as a reference the advancement direction of the material indicated with the arrow X of FIG. 2 , represents a fine weeding station m, that is a station of fine removal of small parts of weed, including those parts that are generated by a plurality of weeding assisting cuts. Once the fine weeding has been carried out, the main body of the weed (through a rough weeding station/process M which will be described in greater detail hereafter) can be detached completely and effectively, without leaving residues, without tearing material or removing undesired parts.
A fine weeding device operates at the fine weeding station m ( FIG. 2 ), with a gripper 3 that a portal 4 supports in a vertical arrangement, allowing the gripper to move along the three coordinates XYZ, in which the plane XY is the one parallel to the plane 1 a and the axis Z is the direction along which the gripper 3 extends.
To such a purpose the portal 4 has a crosspiece 5 which can be displaced along the advancement direction X and along which a carriage 6 moves, in accordance with the direction Y, and in turn supports the fine weeding gripper 3 through a linear actuation system along the direction Z. All such movements, just like those that are not specified otherwise, are controlled by motorizations implemented as obvious to a person skilled in the art. It is in any case worth noting how the movement along Z of the gripper 3 is advantageously carried out by means of a recirculating ball system driven by a direct brushless motor that ensures speed and precision with a repeatability in the order of a hundredth of a millimetre.
The portal 4 also has a suction rod, which is not visible in the figures, which through a suction pad system feeds the sheet and arranges it so as to align the front left corner (imagining an observer which is standing looking towards the same direction as the advance movement direction) with a suitably pre-set reference. During transport the sheet remains lifted in the front part that is gripped by the suction pads but is progressively made to adhere to the plane la in the remaining part towards the tail. The plane 1 a is indeed connected to a vacuum pump system and the friction of the sheet created by the suction during movement ensures a perfect flatness preventing air bubbles or creases from forming on the sheet itself.
Once the sheet has been positioned on the suction work plane at the fine weeding station m, the gripper 3 can carry out the fine removal of the various (small) weed parts, including those created by the plurality of weeding assisting cuts, according to the instructions from the control system, in turn processed on the basis of technical criteria that shall be further explained hereafter.
The gripper 3 is represented in particular in FIG. 3 and includes from top to bottom (the reference is at the work position in alignment with the axis Z) a damper 7 and a pinching or gripping head 8 adapted to come into contact with the adhesive film and to remove it through pinching and lifting, without of course affecting the liner support underneath. The damper 7 has the function of ensuring that the head 8 exerts a pressure with constant intensity on the material to be worked, compensating for possible non-homogeneity in shape of the suction plane.
The head 8 moreover comprises an annular tool-holding flange 12 that can be coaxially connected in a reversible manner, with a quick fit system that can be driven pneumatically, at an inner stem (not visible) of the damper 7 . Once it is removed, the flange can be supported in a suitable manner on a tool changing station through four pins 13 projecting radially from the flange itself. A self-centring pneumatically driven chuck 15 is connected to the flange 12 , again coaxially, on the opposite side of the damper 7 . The chuck is equipped with three radial jaws 16 provided with respective pinching blocks 17 which represent the actual manipulation element of the film/weed to be removed.
In operation, each fine weeding step thus occurs, in brief, with the positioning of the gripper on the appropriate coordinates XY, the jaws being in the open configuration. The device then goes down along the axis Z closing the jaws in a synchronised manner in order to complete the run as they come into contact with the weed to be removed, which is thus gripped between the blocks 17 that are mutually tightened. This action causes there to be a first detachment of the weed, the removal of which is completed with a displacement along XY a new lifting along axis Z and the subsequent unloading or discharge over a sliding belt made from consumable plastic or paper material, with an obvious configuration which is not shown, in view of a new step as the one here just described.
Once the fine weeding phase is over, the sheet proceeds over the plane 1 a and thus enters the already mentioned rough weeding station M in which a weed seizing head 21 of a rough weeding device operates ( FIG. 4 and FIGS. from 7 to 12 ), cooperating in an initial phase with a cutting unit 22 ( FIGS. 5 and 6 ). The rough weeding device has the configuration of a crosspiece arranged along the axis Y above the plane 1 a and it is supported in a mobile manner along the axis X by a lateral guide system 1 c of the plane itself. An adjustment of the position along the axis Z can be also provided, through for example abutment screws to be actuated manually.
The seizing unit or head 21 comprises a front suction rod 23 that takes hold of the sheet and positions it above the cutting unit 22 , embedded in the plane 1 a in an inlet position of the rough weeding station M. In this phase, the suction system of the rough weeding head 21 carries out an opposing effect to the action of a blade housed inside a self-lubricating disk 27 that moves along the axis Y, controlled by a pneumatic piston, through a recirculating ball slide on the entire length of a linear guide 24 . The liner of silicone release paper placed under the self-adhesive plastic material is cut for its entire width at a distance of around 2.5 cm from the front edge of the sheet, so as to define a flap or edge that can be easily folded upwards, with the consequence and the aim that shall soon become clear. The precision with which the blade sinks into the liner is ensured by a micrometer screw, whereas the stop abutment of the knife is ensured by a pneumatic piston 25 that brings the disk 27 in contact with the supporting plane of the sheet. The gap on the axis Z between the knife and the disk thus defines the depth of the cut.
Once the liner has been cut, the sheet still held by the suction rod 23 is brought inside the actual rough weeding station M, making the cutting line of the liner coincide with a reference mark of a device for lifting the head flap of the liner. Such a device is schematically represented and indicated with reference numeral 36 in FIGS. from 13 b to 13 l , and it consists substantially of a bar that can be lifted along the axis Z through linear pneumatic actuators that are not represented, between a lowered position in which it is concealingly integrated inside the plane 1 a and a raised position in which it is capable of folding upwards by 90° the front flap or edge of the sheet, defined by the cutting means indicated above.
The lifting strip is preferably shaped with a staggered or comb-shaped edge that engages with a matching shape of the rough weeding plane, so as to lift the flap or edge at the end margin of the suction area, i.e. with the suction that is in any case active between the teeth of the staggering/comb and assists a lift precisely by 90° of the flap or edge.
A further component of the weed seizing head is a blower 28 that, on a plane that is parallel and adjacent to the plane 1 a , produces an ejection of pressurised air that is capable of covering the entire width (direction Y) and is directed according to X, in a direction that is in accordance with that along which the sheet advances forward. Advantageously, the blower 28 , shown in particular in FIGS. from 7 to 10 , takes the shape of an elongated blade extending along the axis Y with a plurality of adjacent and independent sectors, for example ten, that are driven by respective solenoid valves 29 in order to dispense air, through suitable channels 28 b , during the movement of the sheet only where actually required.
The pressurised air comes out from a system of front slits 28 a of the blower, to which a pair of rollers 30 , 31 are associated, spaced along the direction X and arranged so that the blade is substantially tangent with respect to them. More precisely, a rear roller 30 is made from silicone material, whereas a front roller 31 is preferably made from aluminium with a non-stick coating and is mobile towards and away from the rear roller 30 . The rotation of such rollers is controlled by, and is synchronised with, the forward movement of the whole head, through a pinion and rack transmission (the pitch of the rack being in particular the same as the diameter of the two rollers).
In an upper area of the group, and therefore above the components described above, there are a pull drum 33 with an incomplete development (that is, without a circular sector preferably having an angle that is equal or slightly lower than 90°) and above the drum 33 , a shaft 32 for collecting the weed in a reel (around a core of disposable cardboard), both motorized and arranged with their rotation axis extending along the axis Y. The motorisation of the roller and the shaft is mutually independent, with a torque limiter that can be set in order to ensure the correct tension of the weed, thus avoiding ripping or accumulation thereof. The winder 32 can moreover translate towards and away from the pull drum 33 .
The incomplete pull roll, indeed thanks to its C-shaped section, defines a radial face 33 a that cooperates with a clamp member 35 so as to be able to lock the weed and pull it.
Entering into greater detail as far as the work sequence of the rough weeding process is concerned, and with particular reference to FIGS. from 13 a to 13 l , the blower blade 28 is positioned at the front edge of the sheet, indicated with F. In FIG. 17 a it can be noted also the folding flap Ft indeed generated frontally as a result of the half-cut previously mentioned (cutting line indicated with L). Initially, the radial face 33 a of the C-shaped drum 33 is arranged perpendicular with the plane 1 a , tangent to the back roller 30 and substantially aligned with the cutting line L. Also the front margin of the blower blade is positioned precisely in a way such as to coincide with the cutting line L. The clamp member 35 is open and the front roller 31 is in a forward displaced position ( FIGS. 13 a and 13 b ).
As a result of the lifting of the folder 36 , the folding flap Ft, including both the weed Fs and the liner Fl joined to one another, is folded upwards ( FIG. 13 c ). At this stage the front roller 31 retracts ( FIG. 13 d ) and in cooperation with the rear roller 30 seizes the material, in contact with the adhesive side and directs it upward, whereas, at the same time, the head retracts in direction X, in opposite fashion to the advancement motion of the sheet ( FIGS. 13 d and 13 e ). While this occurs the weed Fs starts becoming detached from the liner of silicone release paper Fl, with the latter kept in contact with the plane la thanks to the suction exerted by it and to the jet of the blower 28 which is responsible for the function, useful in some cases, of preventing the lifting of small parts belonging to the graphics and that must indeed stay placed on the liner.
As visible from FIG. 13 f , the weed Fs has been fed onto the radial face 33 a of the pull drum 33 and the clamp member 35 can close to lock it. A rotation of the drum 33 at this stage continues the removal of the weed Fs which is circumferentially wound around the roll, while in a coordinated manner, the head unit continues to move rearwards. The rotation also brings the weed to the shaft 32 bearing the winding core. In order to start collecting, the shaft 32 moves tangentially alongside the drum 33 ( FIG. 13 h ) so as to be, in turn, wrapped up by the same weed ( FIG. 13 i ). Once the winding has been triggered, the shaft can lift up so as to allow it to freely expand its diameter ( FIG. 13 l ). Of course, for each treated sheet, the aforementioned sequence is repeated and the reel of collected weed continues to grow. Once the diameter of such a reel has reached a set size, a sensor detects it, and stops the apparatus so as to allow the reel itself to be extracted and replaced with an empty cardboard core.
Once made clear that the blower is not necessarily turned on in every circumstances (being it possible that with some materials under treatment the effectiveness of the result is not jeopardized by a lack of the pneumatic action), in a different embodiment, shown in FIGS. from 14 to 17 , the seizing head is provided with a movement of lifting/pulling the weed along the vertical axis Z, movement that in practice replaces the rotation of the rollers 30 , 31 and the winding over the pull drum 33 , and by the same roll, in the first embodiment above described.
The seizing head in this case is indicated with the numeral 121 , and is arranged, in structure and working process, in an analogous fashion with respect to the first embodiment as far as the initial steps are concerned (positioning the sheet and “half cut”). Accordingly, a further description of these steps is here omitted. The figures show a number of components that correspond to those of the previous embodiment, and are therefore indicated with a corresponding numeral in three digits (e. the suction bar 123 ).
The flap obtained with the “half cut”, connected to the rest of the sheet only via the plastic film, is therefore the seizing point that allows for the start of the detachment of the weed, to “free” the graphics. For the sake of a correct working, it is important that the processed sheet be positioned precisely on the suction plane, so that the rear cut results exactly on the folding/lifting line of the flap in the cutting unit; to this purpose the hold carried out by the suction system is kept active during the whole process, to have an appropriate reference for the displacement of the sheet from the half-cut zone to the rough weeding zone.
A blower blade is in this case indicated with the numeral 128 and, suitably turned on by electrovalves, can deliver air during the movement only when and where positively required; the function of this air ejections is as mentioned fundamentally to oppose a possible lift of the graphic parts as the weed is removed. The structure of the blade has a certain flexibility to better accompany the sliding of the removed material and the interaction therewith even when it follows irregular geometric contours due to the particular graphic under process.
An idle roller 139 is associated to the blade 128 and is preferably lined with a silicon material in view of a better grip on the plastic film, In fact, the task of this roller is to lock the sliding of the sheet during the rough weeding process, ensuring a safer hold on the same sheet by the suction plane. Moreover, the compression of the drum on the self-adhesive material ensures that the graphic figures remain attached to the support liner and consequently prevents their lifting/removal as the weed is detached.
The unit including the blade 128 and the roller 139 is mounted on a common movable support 137 , the position of which can be adjusted in the direction Z thanks to recirculating ball linear sliders 138 driven by pneumatic pistons. The result thus obtainable is to drive with a certain adjustable pressure the blade and the roller onto the material during the weeding steps, and to lift the blade in the inactive steps, that is when the unit must be moved without engagement with the sheet material.
The seizure of the weed occurs via plate members 131 seizing the lifted flap and moving upwards, carried by a slider 141 , rising continuously in height along the direction Z, guided by a portal 140 and namely by linear guide means 140 a thereof. The rising is coordinated with the movement of the same portal along the direction X (movement that occurs as in the previous embodiments, and followed by the support 127 of the blade 128 and of the roller 139 that, contrary to the seizing means 131 , remain adjacent with the working plane pressing the sheet). As a function of the different types of material under treatment, it is possible to set the appropriate weed removal strategy by synchronizing the two movements, so that a constant and precise pull of the material is ensured during the whole process as required by the different shapes of the graphics. Depending on the length and nature of the material, it is possible to leave a small portion of the sheet anchored for avoiding fluttering during the movement, thus assisting the subsequent phase of collection of the removed weed.
In this case the collection of the removed weed is carried out by a collection unit 132 ( FIG. 17 ) that rises in height along with the slider 141 on the guide portal, starting from a minimum elevation that is the one the slider has to reach to start the collection. The collection unit 32 comprises two mutually opposed rotating plugs 132 a , one of which is motorized, that form the shaft on which there is engaged the weed reel cardboard core. The increase in width that results from the accumulation of weed on the collection core is compensated thanks to a horizontal recovery movement (along X) by the plugs 132 a . The winding movement is obtained thanks to the motorization of one of the two plugs, possibly with a motor with feedback control through an external encoder. Once the width of the reel of wound weed has reached a customizable preset size, an onboard sensor of the slider commands the stop of the apparatus and the replacement of the core, which is permitted thanks to a pneumatic unlock of the non-motorized plug 132 a.
The various drives are carried out through motors and actuators having an obvious nature to the skilled person and not described in detail.
The present invention provides therefore a weeding device and method capable of making the weeding process effectively automatic (not necessarily in the time order rough after fine as in the example, but possibly even in the contrary order), remarkably reducing the production times and significantly improving the productive results as far as costs and reliability are concerned.
The present invention has been here described with reference to its preferred embodiment. It should be understood that that there may be other embodiments within the same inventive concept, as defined by the scope of protection of the following claims.
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The present invention concerns the field of graphic apparatuses and in particular its object is an apparatus and a relative method for the so-called “weeding” of plastic or paper films having or more self-adhesive, double sided adhesive or electrostatic layers coupled with a support liner treated with a non-stick agent. The apparatus comprises a seizing head ( 21 ) with an air blower ( 28 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of U.S. patent application Ser. No. 09/635,430 filed Aug. 10, 2000, now U.S. Pat. No. 6,500,240, the entire contents of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a dust collector and method for collecting dust, which is used to remove dust, mist, and the like contained in a gas.
In order to efficiently collect fine dust (submicron particles), mist, and the like, the applicant has before proposed a dust collector in Japanese Patent Provisional Publication No. 10-174899 (No. 174899/1998).
This dust collector includes charging means for charging a substance to be collected such as dust and mist contained in a gas, spray means for spraying a dielectric on the substance to be collected charged by the charging means, electric field forming means for forming an electric field for dielectrically polarizing the dielectric sprayed from the spray means, and dielectric collecting means for collecting the dielectric which has arrested the substance to be collected.
The above-described dust collector has a high voltage applied electrode 100 and a ground electrode 200 , shown in FIG. 24, as the electric field forming means, and allows an exhaust gas containing the substance to be collected such as dust and mist (in this example, SO 3 mist indicated by the black dots in the figure) 300 and a dielectric (in this example, water mist) 400 sprayed from the spray means to flow between the electrodes 100 and 200 .
The substance to be collected 300 has been charged, for example, negatively in advance by the charging means. On the other hand, the dielectric 400 is dielectrically polarized by a direct current electric field formed between the electrodes 100 and 200 . Therefore, the substance to be collected 300 is collected by the dielectric 400 by means of the Coulomb's force acting between the particles of dielectric 400 .
When an alternating voltage is applied between the electrodes 100 and 200 as shown in FIG. 25, the polarization polarity of the dielectric 400 changes with time, and the charged substance to be collected moves in a zigzag form. Thus, the substance to be collected 300 is collected by the dielectric 400 by means of the Coulomb's force acting between the particles of dielectric 400 .
According to this dust collector of the earlier application, submicron particles can be collected efficiently despite the compact configuration.
OBJECT AND SUMMARY OF THE INVENTION
In order to further increase the efficiency in collecting the substance to be collected 300 , it is necessary for the dielectric 400 to exist enough up to the upper part (rear part) of the electrodes 100 and 200 . In the conventional collector, however, the dielectric shows a tendency to rarefy at the upper part (rear part) of the electrodes 100 and 200 .
The inventors found that the aforementioned tendency is ascribed to the charging of the dielectric sprayed from the spray means.
Specifically, the particles of dielectric sprayed from the spray means are charged positively or negatively because the particles of dielectric exchange charges at the boundary of a pipe through which the dielectric itself flows. Therefore, the dielectric 400 having been charged positively or negatively is sprayed from the spray means, which is a cause of bringing about the aforementioned tendency as described below.
In FIG. 26 corresponding to FIG. 24, the circle mark applied to the side of the particle of dielectric 400 indicates the charging state of the particle of dielectric 400 . If the charged dielectric 400 is supplied between the electrodes 100 and 200 , the positively charged dielectric 400 is attracted to the electrode 100 , and the negatively charged dielectric 400 is attracted to the electrode 200 by means of the Coulomb's force. Therefore, most of the dielectric 400 is collected by the electrodes 100 and 200 before it arrives at the upper part (rear part) of the electrodes 100 and 200 .
FIG. 27 shows a case where an alternating electric field is applied to between the electrodes 100 and 200 . In this case, the charged dielectric 400 goes while being swayed to right and left with the change cycles of alternating electric field. At this time, the particles of dielectric 400 having a positive and negative charge are attracted to one another and aggregate, so that the distribution concentration of the dielectric 400 decreases toward the upper part of the electrodes 100 and 200 . That is, even if an alternating electric field is applied to between the electrodes 100 and 200 , the dielectric 400 rarefies at the upper part of the electrodes 100 and 200 .
The present invention has been made in view of the above situation, and accordingly an object thereof is to provide a dust collector and method for collecting dust in which the rarefaction of dielectric at the rear part of electric field forming means is prevented, whereby the collecting efficiency can be increased.
To achieve the above object, the present invention provides a dust collector, comprising charging means for charging a substance to be collected, such as dust and mist, contained in a gas; spray means for spraying a dielectric on the substance to be collected charged by the charging means; electric field forming means, having first and second electrodes for forming a direct current electric field, for dielectrically polarizing the dielectric sprayed by the spray means by means of the direct current electric field; dielectric collecting means for collecting the dielectric which has arrested the substance to be collected; and grounding means, provided in the spray means, for electrically grounding the dielectric before being sprayed, wherein a charge of the dielectric is caused to escape by the grounding means so that the dielectric is made electrically neutral.
According to the present invention, since the electrically neutral dielectric is sprayed from the spray means, the arrest of the sprayed dielectric by the electrode of the electric field forming means is restrained. Therefore, a shortage of dielectric in the rear zone of an electric field forming section is prevented, so that the efficiency in collecting the substance to be collected is increased.
A metallic net is used as the grounding means, and the net can be disposed in a flow path of the dielectric in the spray means so as to traverse the flow path. With the use of the metallic net as de-electrifying means, a satisfactory de-electrifying effect can be achieved without obstructing the flow of the dielectric.
Also, the present invention provides a dust collector, comprising charging means for charging a substance to be collected, such as dust and mist, contained in a gas; spray means for spraying a dielectric on the substance to be collected charged by the charging means; electric field forming means, having first and second electrodes for forming a direct current electric field, for dielectrically polarizing the dielectric sprayed by the spray means by means of the direct current electric field; and dielectric collecting means for collecting the dielectric which has arrested the substance to be collected, wherein a plurality of corona discharge sections arranged in the flow direction of the gas at given intervals are formed on the opposed surfaces of the first and second electrodes to generate band-shaped uniform corona discharge perpendicular to the gas flow, and the dielectric is provided with a charge of reverse polarity alternately by the corona discharge.
According to the present invention, the dielectric goes in a zigzag form to the rear zone of the electric field forming means under the action of the charge developed by discharge of the corona discharge section, so that the substance to be collected can be collected very efficiently.
The arrangement interval between the corona discharge sections on the first electrode and the arrangement interval between the corona discharge sections on the second electrode are preferably set so as to be equal to each other. Also, both of the corona discharge sections are preferably provided so as to have an arrangement phase difference of ½ of the arrangement interval in the flow direction of the gas. According to this configuration, corona discharge on the electrodes of the electric field forming section does not oppose, so that the occurrence of spark discharge can be restrained.
The rear parts of the first and second electrodes can be extended, and a plurality of the corona discharge sections can be formed in the flow direction of the gas on one of these extensions only. According to this configuration, the dielectric can be collected at the extension of the electrode of the electric field forming section, so that a demister can be omitted.
Further, the present invention provides a dust collector, comprising charging means for charging a substance to be collected, such as dust and mist, contained in a gas; spray means for spraying a dielectric on the substance to be collected charged by the charging means; electric field forming means, having first and second electrodes for forming a direct current electric field, for dielectrically polarizing the dielectric sprayed by the spray means by means of the direct current electric field; and dielectric collecting means for collecting the dielectric which has arrested the substance to be collected, wherein the distribution of the dielectric sprayed by the spray means is set so that the distribution of the dielectric at the rear part of the first and second electrodes is uniformed.
According to the present invention, the dielectric can be caused to exist uniformly in the rear zone of the electric field forming section, so that the collecting efficiency is increased.
Sill further, the present invention provides a dust collector, comprising charging means for charging a substance to be collected, such as dust and mist, contained in a gas; spray means for spraying a dielectric on the substance to be collected charged by the charging means; electric field forming means, having first and second electrodes for forming a direct current electric field, for dielectrically polarizing the dielectric sprayed by the spray means by means of the direct current electric field; and dielectric collecting means for collecting the dielectric which has arrested the substance to be collected, wherein the spray means is provided with charge providing means for providing the dielectric before being sprayed with a charge having a reverse polarity of the charging polarity of the substance to be collected.
According to the present invention, a repelling force acts between the particles of sprayed dielectric, so that the aggregation of the particles of dielectric in the electric field forming section is prevented, thereby increasing the collecting efficiency.
The charge providing means can be configured so as to supply ionized air to the dielectric before being sprayed. According to this configuration, the dielectric is charged via the ionized air.
Also, the charge providing means can be configured so that magnetism in the direction perpendicular to the flow direction of the dielectric is applied to the dielectric before being sprayed. According to this configuration, the dielectric is charged by the action of the magnetism.
In the dust collectors described above, a plurality of stages of the pair of the spray means and the electric field forming means can be disposed. According to this configuration, the substance to be collected is collected in a dust collecting section of each stage, so that a very high dust collecting efficiency can be obtained.
In this configuration, fresh water is sprayed from spray means of at least the most downstream stage of the plurality of spray means, and circulating water is sprayed from spray means excluding the spray means which sprays freshwater. According to this configuration, since fresh water is sprayed from spray means of at least the most downstream stage, the collecting efficiency is further increased. Therefore, this configuration is especially advantageous in preventing the outflow of harmful substances.
The spray means of the most downstream stage can be provided with a nozzle for atomizing the fresh water to an average diameter not larger than 50 μm. If such a nozzle is provided, the nozzle is not clogged, thereby maintaining a high dust collecting efficiency, and the quantity of fresh water used can be decreased.
The dust collectors described above can be configured so as to further comprise a dielectric circulating system for supplying the dielectric from a dielectric storage tank to the spray means and for returning the sprayed dielectric from the spray means to the storage tank; dielectric supply means for supplying a fresh dielectric to the dielectric storage tank; dielectric discharge means for discharging the dielectric in the dielectric storage tank; absorbent charging means for charging an absorbent in the dielectric storage tank, the absorbent being used to absorb a reaction product produced by a substance in the gas; and control means for controlling the quantity of dielectric supplied by the dielectric supply means and the quantity of dielectric discharged by the dielectric discharge means so that the concentration of the reaction product exhibits a value within a given range and for controlling the quantity of absorbent charged by the absorbent charging means so that the pH value of the dielectric exhibits a value within a given range.
According to this configuration, the deterioration in dielectric can be prevented, and also harmful gas can be absorbed and removed positively.
A method for collecting dust in accordance with the present invention comprises a first step of charging a substance to be collected, such as dust and mist, contained in a gas; a second step of causing the gas having undergone the first step to flow from the downside to the upside; a third step of spraying a dielectric on the substance to be collected contained in the gas flowing from the downside to the upside; a fourth step of dielectrically polarizing the sprayed dielectric and of causing the dielectric to arrest the substance to be collected by means of the Coulomb's force created by the polarization; and a fifth step of collecting the dielectric which has arrested the substance to be arrested.
According to the present invention, the gas in which the substance to be collected has been charged is moved from the downside to the upside, so that a nonuniform distribution of the substance to be collected caused by the action of the gravity is not formed. Therefore, the substance to be collected is distributed uniformly, and is collected efficiently.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic longitudinal sectional view showing a general construction of a dust collector in accordance with the present invention;
FIG. 2 is a schematic perspective view showing a construction of a preliminary charging section;
FIG. 3 is a schematic perspective view showing a construction of a dust collecting section;
FIG. 4 is a sectional view showing a construction of a spray section;
FIG. 5 is a sectional view showing another construction of the spray section;
FIG. 6 is a schematic perspective view showing another construction of the dust collecting section;
FIG. 7 is a schematic perspective view showing a construction of a corona discharge section;
FIG. 8 is a partial perspective view showing a mode of discharge of the corona discharge section;
FIG. 9 is a plan view showing a construction of small protrusions constituting the corona discharge section;
FIG. 10 is a sectional view taken along the line A—A of FIG. 9;
FIG. 11 is a sectional view taken along the line B—B of FIG. 9;
FIG. 12 is a plan view showing another construction of the small protrusions constituting the corona discharge section;
FIG. 13 is a sectional view taken along the line C—C of FIG. 12;
FIG. 14 is a sectional view taken along the line D—D of FIG. 12;
FIG. 15 is a plan view showing another construction of the corona discharge section;
FIG. 16 is a sectional view taken along the line E—E of FIG. 15;
FIG. 17 is a sectional view taken along the line F—F of FIG. 15;
FIG. 18 is a schematic sectional view showing a general distribution mode of dielectric in the dust collecting section;
FIG. 19 is a schematic sectional view typically showing a spray mode of dielectric in the dust collector in accordance with the present invention;
FIG. 20 is a sectional view showing a construction of the spray section used in the dust collector in accordance with the present invention;
FIG. 21 is a sectional view showing another construction of the spray section used in the dust collector in accordance with the present invention;
FIG. 22 is a perspective view for explaining the operation of the spray section shown in FIG. 21;
FIG. 23 is a schematic sectional view showing another embodiment of the dust collector in accordance with the present invention;
FIG. 24 is an explanatory view showing a general principle of dust collection in a direct current electric field;
FIG. 25 is an explanatory view showing a general principle of dust collection in an alternating electric field;
FIG. 26 is an explanatory view typically showing behavior of the particles of dielectric in the direct current electric field in a conventional dust collector; and
FIG. 27 is an explanatory view typically showing behavior of the particles of dielectric in the alternating electric field in a conventional dust collector.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a schematic longitudinal sectional view showing a general construction of a dust collector to which the present invention is applied. This dust collector has a preliminary charging section 1 , a spray section 2 , and a dust collecting section 3 .
The preliminary charging section 1 includes, as shown in FIG. 2, a plurality of ground electrodes (positive electrodes) 4 arranged in parallel and discharge electrodes (negative electrodes) 5 disposed between the ground electrodes 4 . The discharge electrode 5 is configured so that a plurality of (three, in this example) conductive rods 5 a are disposed vertically in a plane parallel with the ground electrode 4 , and a large number of spine-like portions 5 b are arranged in the vertical direction of the rod 5 a at appropriate intervals.
The spray section 2 is, as shown in FIG. 3, provided with a large number of nozzles 6 for spraying a dielectric, which are arranged under the dust collecting section 3 . The nozzles 6 are formed on a plurality of pipes 7 arranged horizontally at appropriate intervals.
As shown in FIG. 1, the pipe 7 is connected to a dielectric storage tank 8 via a pipe 13 . Therefore, if a dielectric (water in this example) 10 in the storage tank 8 is drawn up by a pump P interposed in the pipe 13 , the mist-like dielectric 10 is sprayed from the nozzles 6 .
The dust collecting section 3 includes, as shown in FIG. 3, a plurality of ground electrodes 11 arranged in parallel and high voltage applied electrodes 12 interposed between the ground electrodes 11 .
In the dust collector constructed as described above, as indicated by the arrow mark in FIG. 1, an exhaust gas from which dust is to be removed (for example, an exhaust gas generated when coal, heavy oil, or the like is burned) is introduced into the preliminary charging section 1 . The exhaust gas passes between the ground electrode 4 and the discharge electrode 5 shown in FIG. 2 . At this time, a substance to be collected such as dust, mist, and the like contained in the exhaust gas is provided with a charge by corona discharge occurring between the electrodes 4 and 5 . In this example, by the provision of the charge, the substance to be collected is charged negatively.
The exhaust gas having passed through the preliminary charging section 1 flows into a gas absorbing zone 15 shown in FIG. 1, and then, after flowing upward, it is introduced into the dust collecting section 3 together with the dielectric 10 sprayed from the spray section 2 .
The sprayed dielectric 10 is dielectrically polarized by a direct current electric field or an alternating electric field acting between the electrodes 11 and 12 (see FIG. 3) of the dust collecting section 3 . Therefore, the negatively charged substance to be collected sticks to the dielectric 10 by means of the Coulomb's force acting between the particles of dielectric 10 .
The dielectric to which the substance to be collected has stuck is recovered in a dielectric collecting section 16 consisting of a demister or the like. Therefore, a clean gas from which the substance to be collected has been removed is discharged from the dielectric collecting section 16 .
Since this dust collector is applied to the treatment of a harmful gas, the sprayed dielectric 10 absorbs some of the harmful gas. Specifically, for example, in the case where the dust-containing gas contains a harmful gas such as SOx, the dielectric 10 absorbs the SOx during the time when the dielectric 10 is used by being circulated.
If the dielectric 10 absorbs a harmful gas in this manner, the pH value of the dielectric 10 decreases, so that a problem of corrosion etc. arises. In this dust collector, therefore, in order to solve the above problem, there are provided a fresh water supply pipe 51 in which a valve 50 is interposed, a discharge pipe 53 in which a valve 52 is interposed, an absorbent supply pipe 55 in which a valve 54 is interposed, and a controller 56 or the like for controlling the valves 50 , 52 and 54 .
Specifically, the dielectric 10 in the storage tank 8 contains a reaction product according to the absorption amount (treatment amount) of SOx or the like contained in the dust-containing gas. Therefore, the controller 56 controls, based on the output of a concentration sensor 57 for detecting the in-liquid concentration of the reaction product, the valves 50 and 52 so that the in-liquid concentration exhibits a value within a given range. That is to say, the controller 56 regulates the quantity of fresh water poured into the tank 8 and the quantity of dielectric 10 discharged from the tank 8 .
Also, the controller 56 controls, based on the output of a pH sensor 58 for detecting the pH concentration of the dielectric 10 in the tank 8 , the valve 54 so that the pH concentration exhibits a value within a given range. That is to say, the controller 56 regulates the quantity of absorbent (for example, NaOH and Mg) charged into the tank 8 to absorb the reaction product.
If the in-liquid concentration of the reaction product and the pH value of the dielectric 10 are controlled as described above, not only the corrosion or the like can be prevented, but also the harmful gas can be removed positively by utilizing the harmful gas absorbing function of the dielectric 10 .
Although the in-liquid concentration of the reaction product is controlled based on the output of the concentration sensor 57 in the above description, the concentration control can be carried out without the use of the concentration sensor 57 .
Specifically, since the average degree of increase in the in-liquid concentration is known in advance by an experiment etc., the quantity of fresh dielectric (freshwater) poured into the tank 8 and the quantity of dielectric discharged from the tank 8 , which correspond to the degree of increase, are determined in advance, and the valves 50 and 52 are controlled so that the poured quantity and discharged quantity are attained. Thereby, the in-liquid concentration of the reaction product can be made within a given range.
First, embodiments in which the direct current electric field is formed between the electrodes 11 and 12 shown in FIG. 3 will be explained.
(Embodiment 1)
As described above, the dielectric 10 sprayed from the spray section 2 has been charged positively or negatively. When the direct current electric field is formed between the electrodes 11 and 12 of the dust collecting section 3 , the charging of the dielectric 10 decreases the efficiency in collecting the substance to be collected for the aforementioned reason (sticking of the dielectric to the electrode) explained with reference to FIG. 26 .
Thereupon, in the dust collector of embodiment 1, the spray section is formed as shown in FIG. 4 . This spray section is configured so that an earth net 17 is disposed in the nozzle 6 , and an earth net 18 is disposed at a slightly upstream position from the position where the nozzle 6 is disposed in the pipe 7 .
The earth nets 17 and 18 , which are made of a metal, are provided so as to traverse the flow path of the dielectric 10 . The pipe 7 and the nozzle 6 are grounded, so that the earth nets 17 and 18 fitted to these elements are also grounded.
The charged dielectric 10 flowing through the pipe 7 is de-electrified during the time when it passes through the earth nets 17 and 18 . As a result, the dielectric 10 that has been de-electrified, that is, that is electrically neutral, is sprayed from the nozzle 6 .
The de-electrified dielectric 10 having been sprayed from the nozzle 6 is not subjected to the Coulomb's force created by the direct current electric field between the electrodes 11 and 12 when it is introduced to between the electrodes 11 and 12 shown in FIG. 3 . Therefore, most of the dielectric 10 moves toward the upper part (rear part) of the electrodes 11 and 12 without being arrested by the electrodes 11 and 12 . As a result, even at the upper part of the electrodes 11 and 12 , the substance to be collected is efficiently collected by the dielectric 10 .
With the use of the earth nets 17 and 18 as de-electrifying means, a satisfactory de-electrifying effect can be achieved without obstructing the flow of the dielectric 10 .
In the spray section 2 , a two fluid nozzle as shown in FIG. 5 can be used. For this two fluid nozzle 60 , the dielectric 10 is introduced from the side of the nozzle 60 via an introduction pipe 61 , and at the same time, a pressurized air is introduced via an air supply pipe 62 continuous with the lower part of the nozzle 60 , so that the dielectric 10 can be sprayed from the tip end of the nozzle 60 .
When this two fluid nozzle 60 is used, an earth net 20 is disposed at the outlet of the introduction pipe 61 , and an earth net 21 is disposed at a slightly upstream position from the position where the nozzle 60 is disposed in the pipe 7 . Thereby, the de-electrified dielectric 10 is sprayed from the nozzle 60 as in the case of the nozzle 6 shown in FIG. 4 .
FIG. 6 shows an embodiment in which a plurality of corona discharge sections 110 and 120 arranged in the flow direction of the gas are formed on the opposed surfaces of the electrodes 11 and 12 of the dust collecting section 3 , respectively. In this embodiment as well, the direct current electric field is formed between the electrodes 11 and 12 .
As shown in FIG. 7, the corona discharge sections 110 and 120 are located at intervals of L, and have an arrangement phase difference of L/2 with respect to each other in the flow direction of the exhaust gas.
The corona discharge sections 110 and 120 each have a configuration in which small protrusions 110 a and 120 a are disposed closely with a pitch P in the direction perpendicular to the gas flow. Therefore, as shown in FIG. 8, a band-shaped corona current can be supplied from the corona discharge section 110 ( 120 ) to the opposed electrode 12 ( 11 ).
In FIG. 6, when its initial charging polarity is negative, the dielectric 10 going between the electrodes 11 and 12 is transferred to the electrode 11 by the Coulomb's force created by the direct current electric field between the electrodes 11 and 12 .
The corona discharge sections 110 and 120 release the positive and negative charges, respectively, by corona discharge between the electrodes. Therefore, the dielectric 10 transferred to the electrode 11 is charged positively by the charge released from the corona discharge section 110 , with the result that the dielectric 10 is transferred to the electrode 12 . The dielectric 10 transferred to the electrode 12 is charged negatively by the charge released from the corona discharge section 120 , so that the dielectric 10 is transferred again to the electrode 12 . That is to say, the dielectric 10 transfers while being provided with a charge of reverse polarity alternately.
Thus, the dielectric 10 (water mist in this example) goes upward between the electrodes 11 and 12 while transferring in a zigzag form, and is dielectrically polarized by the electric field acting between the electrodes 11 and 12 . On the other hand, the particles of substance to be collected (SO 3 mist in this example) 9 indicated by the black dots scarcely move in the direction such as to traverse the gas flow (right and left direction in FIG. 6 ). As a result, the dielectric 10 goes in a zigzag form while collecting the substance to be collected 9 by means of the Coulomb's force acting between the particles of dielectric 10 .
The particle size of the dielectric 10 is appreciably larger than that of the substance to be collected 9 , so that the quantity of charge given to a unit weight of the dielectric 10 per unit time is considerably larger than that of the substance to be collected 9 . The above-described operation such that the dielectric 10 collects the substance to be collected 9 while going in a zigzag form is attained by a difference in the quantity of charge given to a unit weight per unit time.
According to this embodiment 2 in which the charges developed by the discharge of the corona discharge sections 110 and 120 are utilized, the dielectric 10 can be caused to exist up to the upper part of the electrodes 11 and 12 , so that the efficiency in collecting the substance to be collected 9 is increased.
If the arrangement interval L between the corona discharge sections 110 and 120 is set so as to be smaller than the given interval, the discharge sections 110 and 120 are opposed to each other and a locally high electric field is formed in a spot form, so that there is a fear of the occurrence of spark discharge. Therefore, the arrangement interval L is preferably set so as to be L≧d (d denotes a distance between the electrodes 11 and 12 ).
In this embodiment 2, the upper ends (rear end) of the electrodes 11 and 12 are extended by an appropriate length D, and the corona discharge sections 120 are formed at the extension of the electrode 12 only. In this configuration, the dielectric 10 that has arrested the substance to be collected 9 and has arrived at the extensions of the electrodes 11 and 12 is finally attracted and collected by the electrode 11 , that is, the extension of the electrode 11 has a function of collecting the dielectric 10 . Therefore, the demister 16 shown in FIG. 1 can be omitted.
The corona discharge sections 110 may be formed at the extension of the electrode 11 only. In this case, the dielectric 10 that has arrested the substance to be collected 9 is finally attracted and collected by the electrode 12 .
FIG. 9 is a plan view showing an example of the small protrusions 110 a , 120 a constituting the corona discharge section 110 , 120 . FIGS. 10 and 11 are sectional views taken along the lines A—A and B—B of FIG. 9, respectively. The small protrusion 110 a , 120 a shown in these figures is formed into a triangular shape by cutting and raising a metal plate forming the electrode 11 , 12 . These protrusions 110 a , 120 a , having a sharp tip end, are advantageous in concentrating the electric field.
FIG. 12 is a plan view showing another example of the small protrusions 110 a , 120 a . FIGS. 13 and 14 are sectional views taken along the lines C—C and D—D of FIG. 12, respectively. This small protrusion 110 a , 120 a is formed by welding a spine-like stud to the electrode 11 , 12 .
FIG. 15 is a plan view showing another construction of the corona discharge section 110 , 120 . FIGS. 16 and 17 are sectional views taken along the lines E—E and F—F of FIG. 15, respectively. The corona discharge section 110 , 120 is made up of conductive electrode reinforcing pipes 19 a fixed to both sides of the electrode 11 , 12 and small-diameter conductive wires 19 c stretched between the electrode reinforcing pipes 19 a via conductive wire mounting pieces 19 b.
According to this corona discharge section 110 , 120 , a band-shaped corona current can be supplied from the wire 19 c of the discharge section 110 , 120 to the opposed electrode 12 , 11 .
FIG. 18 shows a distribution mode of dielectric 10 in the dust collecting section 3 in the case where the direct current electric field is formed between the electrodes 11 and 12 and the dielectric 10 sprayed from the spray section 2 is charged negatively. As shown in FIG. 18, the distribution of the dielectric 10 is uniform in the lower zone of the electrodes 11 and 12 , but much of the dielectric 10 is distributed on the side of the electrode 11 in the upper zone thereof. The reason for this is that the negatively charged dielectric 10 is attracted to the positive electrode 11 as it transfers to the upper part of the electrodes 11 and 12 .
If a nonuniform distribution of the dielectric 10 is formed in the upper zone of the electrodes 11 and 12 as described above, the efficiency in collecting the substance to be collected decreases in the upper zone.
(Embodiment 3)
FIG. 19 shows another embodiment of the present invention in which the above problem is solved. In this embodiment, the distance between the electrodes 11 and 12 is increased, and the right and left nozzles 6 of the spray section are substantially shifted from the middle position between the electrodes 11 and 12 to a position close to the electrode 12 .
According to this configuration, since the dielectric 10 sprayed from both of the right and left nozzles 6 is supplied to the periphery of the electrode 12 , much of dielectric 10 is distributed on the side of the electrode 12 .
The dielectric 10 , which has been charged negatively, transfers upward in the dust collecting section 3 while being subjected to an attracting force from the positive electrode 11 . Therefore, the dielectric 10 , which has initially been distributed more on the side of the electrode 12 , is uniformly distributed at the upper part of the dust collecting section 3 .
According to this embodiment 3, the dielectric 10 can be caused to exist uniformly at the upper part (rear part) of the dust collecting section 3 , so that the substance to be collected 9 can be collected enough even at the upper part, resulting in an increase in the collecting efficiency.
Even in the case where the dielectric 10 is charged positively, the distribution of the dielectric sprayed from the spray section is set so that the distribution of the dielectric 10 is made uniform at the rear part of the electrodes 11 and 12 .
Next, an embodiment in which the alternating electric field is formed between the electrodes 11 and 12 shown in FIG. 3 will be explained.
(Embodiment 4)
When the alternating electric field is formed between the electrodes 11 and 12 , as described with reference to FIG. 27, there occurs a phenomenon that the particles of dielectric 10 aggregate each other. In order to prevent the aggregation of the particles of dielectric 10 , it is necessary only that the mist 10 be charged in advance so as to have the same polarity. This is because the particles of dielectric 10 repel each other due to the charging.
Thereupon, in the dust collector of this embodiment 4, the spray section 2 is configured as shown in FIG. 20 . This spray section 2 has a charging section 25 provided at a slightly upstream position from the nozzle 6 in the pipe 7 to obtain the charged dielectric 10 . The charging section 25 includes an air supply pipe 26 whose tip end is open in the pipe 7 , an electrode 27 projecting in the air supply pipe 26 , and a direct current source 28 for applying a high voltage to the electrode 27 .
When pressurized air is introduced into the air supply pipe 26 , the air is provided with a positive charge from the electrode 27 , so that the air is ionized positively. The positively ionized air is injected into the dielectric 10 in the pipe 7 as bubbles from the tip end of the air supply pipe 26 , so that the dielectric 10 is positively charged by the positive ion of the air. As the result, the positively charged dielectric 10 is sprayed from the nozzle 6 .
The positively charged particles of dielectric 10 are subjected to a repelling force therebetween, so that they do not aggregate between the electrodes 11 and 12 in the dust collecting section 3 . Therefore, the dielectric 10 exists enough even at the upper part of the dust collecting section 3 , thereby increasing the efficiency in collecting the substance to be collected.
The spray section 2 shown in FIG. 21 uses a magnet 31 , 32 as a means for obtaining the charged dielectric 10 . The magnet 31 , 32 is disposed at a slightly upstream position from the nozzle 6 in the pipe 7 so that the tip end portions thereof are opposed to each other in the pipe 7 . The magnet 31 , 32 is housed in a case 33 having electrical insulating quality and non-magnetism.
Between the tip end portions of the magnet 31 , 32 , a magnetic flux B is produced as shown in FIG. 22 . The dielectric (water in this example) 10 flows in the X direction perpendicular to the Z direction of the magnetic flux B, so that an electromotive force e in the direction (Y direction) perpendicular to the X and Y directions is created. The electromotive force e is created based on Lorentz's law.
Ions and electrons in the dielectric 10 move in the direction of the electromotive force e or the direction opposite to this according to the polarity thereof. Electrodes 33 A and 33 B are disposed on one side and the other side of the flow path of the dielectric 10 so as to be perpendicular to the direction of the electromotive force e. The electrode 33 A, which is located in the direction opposite to the direction of the electromotive force e, is grounded.
The dielectric 10 passes through an electric field formed between the electrodes 33 A and 33 B by the electromotive force e. Therefore, the negative ions and electrons in the dielectric 10 flow out via the grounded electrode 33 A. As a result, positive ions remain in the dielectric 10 having passed through between the electrodes 33 A and 33 B. That is to say, the dielectric 10 is charged positively by passing through between the electrodes 33 A and 33 B.
The positively charged dielectric 10 is supplied to the nozzle 6 shown in FIG. 21, so that the positively charged dielectric 10 is sprayed from the nozzle 6 . Thereafter, the positively charged dielectric 10 transfers up to the upper part of the dust collecting section 3 without being aggregated, as described above. Therefore, a shortage of the dielectric 10 at the upper part can be avoided.
In the embodiment shown in FIGS. 20 and 21, the dielectric 10 is charged positively based on the fact that the charging polarity of the substance to be collected 9 in the preliminary charging section 1 is negative. In the case where the charging polarity of the substance to be collected 9 is positive, the dielectric 10 is charged negatively. In this case, the dielectric 10 can be charged negatively by using charging means corresponding to the charging means shown in FIGS. 20 and 21.
(Embodiment 5)
FIG. 23 shows an embodiment in which a plurality of stages (two stages in this example) of the pair of the spray section 2 and the dust collecting section 3 are disposed in the direction of the gas flow. This embodiment can be applied to both the case where the direct current electric field is formed between the electrodes 11 and 12 of the dust collecting section 3 and the case where the alternating electric field is formed.
According to this configuration, the substance to be collected that has not been collected in the first-stage dust collecting section 3 is collected in the second-stage dust collecting section 3 , so that a very high dust collecting efficiency can be attained.
In this embodiment, circulating water is used as the dielectric 10 supplied to the first-stage spray section 2 , and fresh water is used as the dielectric 10 supplied to the second-stage spray section 2 . Thus, the outflow of harmful substances contained in the dielectric 10 from the demister 16 can be restrained to the utmost.
In this embodiment as well, as in the case of the dust collector shown in FIG. 1, there are provided dielectric supply/discharge means and absorbent charging means, having the valves 50 , 52 and 54 , the controller 56 , the sensors 57 and 58 , and the like. Therefore, the concentration of the reaction product in the dielectric 10 can be controlled so as to be a concentration within a given range, and also the pH value of the dielectric 10 can be controlled so as to be a value within a given range. In this embodiment, however, the fresh water supply valve 50 is provided in the supply pipe 7 of the second-stage spray section 2 .
Although the number of stages of the pair of the spray section 2 and the dust collecting section 3 is two in this embodiment, the number of stages can be set at three or more. In this case, fresh water may be supplied to at least the final-stage spray section 2 .
Also, when the outflow of harmful substances poses no problem, it is a matter of course that circulating water can be sprayed even in the final-stage spray section 2 .
It is preferable that the nozzle 6 of the spray section 2 for spraying the fresh water as the dielectric 10 have a function of being capable of atomizing the fresh water to an average diameter not larger than 50 μm to decrease the quantity of fresh water used and to increase the dust collecting efficiency. The reason for this will be described below.
In the case where fine dust or mist such as SO 3 is the substance to be collected, in order to efficiently collect the substance to be collected, it is necessary only that water mist be caused to float as close as possible to the substance to be collected.
In order to cause the water mist to float close to the substance to be collected, the water mist must be atomized as small as possible. The reason for this is that even when the same quantity of dielectric is sprayed, the smaller the particles of the water mist are, the larger the number of scattered particles is, and resultantly, the water mist can be brought close to the substance to be collected.
Because fresh water contains no foreign matter, the nozzle 6 having a function of being capable of atomizing the fresh water to, for example, an average diameter not larger than 50 μm can be used. As a nozzle having such a function, there are well known a one fluid nozzle in which the spray pressure is high (for example, 5 kg/cm 2 G) and the foreign matter passing diameter is not larger than 1 mm, a two fluid nozzle additionally using assist air, and the like.
Since a solid matter etc. of the substance collected in the circulating water exist as impurities in the circulating water, when the circulating water is used as the dielectric, the foreign matter passing diameter of nozzle cannot be decreased. Therefore, it is necessary to use a general-purpose one fluid nozzle or two fluid nozzle to spray the circulating water. In this case, the average diameter of the obtained water mist is at the level of about 100 to 200 μm at least.
Comparing the case where a general nozzle for spraying water mist having an average diameter of 170 μm is used with the case where a special nozzle for spraying water mist having an average diameter of 20 μm is used, the necessary quantity of water for obtaining the same dust collecting efficiency differs greatly. In an experiment, it has been verified that the necessary quantity of water in the latter case is decreased to ⅛ or less of the former case.
The circulating water can be used in a large quantity. However, the quantity of the fresh water used must be decreased for the reason of the necessity of decreasing a utility and for other reasons. In the embodiment shown in FIG. 25, a general-purpose nozzle is used as the nozzle 6 of the first-stage spray section 2 , which sprays circulating water as the dielectric 10 , and a special nozzle capable of atomizing fresh water to an average diameter not larger than 50 μm is used as the nozzle 6 of the second-stage spray section 2 , which sprays the fresh water as the dielectric 10 . Thereby, the nozzle is not clogged, thereby maintaining a high dust collecting efficiency, and the quantity of fresh water used is decreased.
Although water is used as the sprayed dielectric 10 in the embodiments described above, the dielectric 10 is selected appropriately according to the composition of the substance to be collected 9 . For example, when the gas containing the substance to be collected 9 is an acidic gas such as hydrogen chloride or sulfur dioxide, an alkaline absorbing solution etc. represented by an aqueous solution of sodium hydroxide are used as the dielectric 10 , so that gas absorption can also be effected.
Also, the sprayed dielectric 10 is not limited to a liquid. For example, powder of activated carbon etc. having a charging function can be used as the dielectric 10 . The dielectric consisting of liquid such as water and the dielectric consisting of the powder can be sprayed at the same time, or a mixture of the liquid and powder can be sprayed.
Further, although the dielectric 10 is sprayed upward in the embodiments described above, the dielectric 10 may be sprayed downward or horizontally.
Still further, although the exhaust gas having passed through the preliminary charging section 1 is moved along the flow path directed from the downside to the upside, the exhaust gas can be moved along a flow path directed horizontally.
However, the movement of the exhaust gas along the flow path directed from the downside to the upside is more advantageous in increasing the efficiency in collecting the substance to be collected. The reason for this is that a nonuniform distribution of the substance to be collected in the exhaust gas caused by the action of the gravity is not formed, so that the substance to be collected is distributed uniformly.
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A dust collector for collecting dust, in which the rarefaction of a dielectric at the rear part of electric field forming apparatus is prevented, whereby the collecting efficiency can be increased. The dust collector includes a charging device for charging a substance to be collected, such as dust and mist, contained in a gas; a sprayer device for spraying a dielectric on the substance to be collected which is charged by the charging device; an electric field forming device, having first and second electrodes and which form a direct current electric field and dielectrically polarize the dielectric sprayed by the spray device; and a dielectric collecting device for collecting the dielectric which has arrested the substance to be collected. The spray device includes grounding device and for electrically grounding the dielectric before being sprayed to let a charge of the dielectric escape.
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The Sequence Listing submitted in text format (.txt) filed on Nov. 14, 2014, named “SEQLIST_OP201409002US.txt”, created on Nov. 11, 2014, 1.07 KB), is incorporated herein by reference.
BACKGROUND OF INVENTION
Field of the Invention
The present disclosure relates to a new use of muramyl-dipeptide and generally relates to composition comprising muramyl-dipeptide for preventing bone loss, promoting bone regeneration or bone formation.
Description of the Related Art
Bone is a dynamic tissue that preserves skeletal size, shape, and structural integrity and kept in balance through mineral homeostasis, which is maintained through a balance between osteoblastic bone formation and osteoclastic bone resorption.
Osteoporosis is a metabolic disease which is induced with decrease in bone mass caused by aging, smoking, menopause and lack of exercise, and is widely recognized as a major public health problem and represented by fractures of the proximal femur, spine and the hipbone for which the number increases as the population ages
Widely used medications for treating osteoporosis are antiresorptive type of drugs that slow bone loss by suppressing the function of osteoclast. Among them is bisphosphonates. Bisphosphonates are the most commonly prescribed drugs and proven to be effective in treating osteoporosis. However, long-term adverse effects such as osteonecrosis of the jaw have been reported. However for more complete treatment of the disease, anabolic drugs that increase the rate of bone formation are also required.
Anabolic drugs that increase the rate of bone formation is based on a parathyroid hormone. Teriparatide is currently the only osteoporosis medicine approved by the FDA that rebuilds bone. However, burden on the patients due to their high cost combined with variable efficacy depending on the patients limits their use. Therefore, there are needs for the development of new improved anabolic drugs.
Meanwhile, one of the components that are found in cell walls of the bacteria including ones found in normal flora of bacteria in human body is peptidoglycan which is also found in human bone marrow. Peptidoglycan is known to promote immunity as well as to reduce feces by promoting digestion and absorption of feed and to reduce odor by suppressing the generation of ammonia and hydrogen sulfide. However, due to its difficulty associated with the purification, peptidoglycan is usually used as a form of muramyl-dipeptide, which is a motif common to both gram negative and positive bacteria.
Korean Patent Application Publication No. 2010-7005626 discloses a use of Ac-muramyl-Ala-D-Glu-NH2 (MDP) and Ser-Phe-Leu-Leu-Arg-OH for preventing or treating cancer, infectious disease, fibrous disease, inflammatory disease and nervous disease.
U.S. Pat. No. 4,684,625 discloses a method for enhancing the anti-infective activity of muramyldipeptide derivatives.
U.S. Pat. No. 5,292,506 discloses a muramyl-dipeptide derivatives and influenza vaccine comprising the derivatives.
These documents do not disclose the use of muramyl-dipeptide for preventing bone loss, promoting bone regeneration or bone formation. Therefore there exist needs to develop a safe and effective new drug that can treat osteoporosis and related disease by increasing bone formation.
DETAILED DESCRIPTION OF THE INVENTION
Problems to be Solved
The present disclosure is to provide a therapeutic composition for treating osteoporosis, which is an anabolic drug that increases the rate of bone formation as well as amenable to a mass production with a relatively low cost.
SUMMARY OF THE INVENTION
In one aspect the present disclosure provides a pharmaceutical composition for preventing bone loss or promoting bone regeneration or bone formation, which comprises a muramyl-dipeptide, an analog thereof, a derivative thereof or a pharmaceutically acceptable salt thereof.
In one embodiment, the muramyl-dipeptide of the present composition has a structure represented by formula 1:
wherein
R 1 is an acyl having 1 to 22 carbon atoms;
R 2 is an acyl having 1 to 22 carbon atoms;
R 3 is a lower alkyl having 1 to 4 carbon atoms;
R 4 is a hydrogen, an alkyl having 1 to 22 carbon atoms, a phenyl, or a phenyl-lower alkyl having a total of 6 to 15 carbon atoms, wherein the alkyl, phenyl and phenyl-lower alkyl may be substituted with one or more —OH, —OR 6 , —OC(O)R 6 , —C(O)R 6 , —NH 2 , —NHR 6 or —N(R 6 ) 2 groups, wherein R 6 is an alkyl having 1 to 4 carbon atoms;
R 5 is a hydrogen, an alkyl having 1 to 22 carbon atoms, a phenyl or a phenyl-lower alkyl having a total of 6 to 15 carbon atoms, wherein the alkyl, phenyl and phenyl-lower alkyl may be substituted with one or more —OH, —OR 6 , —OC(O)R 6 , —C(O)R 6 , —NH 2 , —NHR 6 or —N(R 6 ) 2 groups, wherein R 6 is an alkyl having 1 to 4 carbon atoms;
X is an aminoacyl selected from the group consisting of L-alanyl, L-tryptophanyl, L-valyl, L-lysyl, L-leucyl, L-ornithyl, L-isoleucyl, L-arginyl, L-α-aminobutyryl, L-histidinyl, L-seryl, L-glutamyl, L-threonyl, L-glutaminyl, L-methionyl, L-aspartyl, L-cysteinyl, L-asparaginyl, L-phenylalanyl, L-prolyl, L-tyrosyl and L-hydroxyprolyl; and
Y is a D-glutamic acid or D-aspartic acid, a (C 1-22 alkyl)ester thereof, a di(C 1-22 alkyl)ester thereof, an amide thereof, a (C 1-4 alkyl)amide thereof, a di(C 1-4 alkyl)amide thereof, or a (C 1-22 alkyl)ester-(C 1-4 alkyl)amide thereof.
In one embodiment, MDP of the present composition has a structure represented by formula 1 above, wherein R 1 , R 2 , R 4 and R 5 are each hydrogen, and R 3 is hydrogen or methyl.
In other embodiment, MDP of the present composition has a structure represented by formula 1 above, wherein X is L-alanyl, L-valyl, L-α-aminobutyryl, L-seryl or L-threonyl.
In other embodiment, MDP of the present composition has a structure represented by formula 1 above, wherein Y is D-isoglutamine, D-aspartamine or D-asparagine.
In other embodiment, MDP of the present composition is muramyl-dipeptide is selected from the group consisting of N-acetylmuramyl-L-alanyl-D-isoglutamine, N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine, N-acetylmuramyl-L-valyl-D-isoglutamine, and N-acetylmuramyl-L-seryl-D-isoglutamine.
It was found in the present disclosure that MDP promoted the differentiation of osteoblasts increasing the expression of bone related genes but without affecting osteoclasts, for example without increasing the number of osteoclasts and thus is very effective for the bone formation. Further the factors secreted from the osteoblasts that were increased by the present composition may further suppress the generation of osteoclasts. Thus the present composition can be advantageously used for increasing the bone formation and also preventing bone loss by osteoclasts.
Thus the present composition can be advantageously used for deformity correction, dental correction, bone fracture treatment, osteosynthesis, bone regeneration of false joints, bone formation, or bone grafting.
In other aspect, the present disclosure provides a health food supplement, a health functional food or a food additive.
In a further aspect, the present disclosure provides a method for preventing bone loss or promoting bone regeneration or bone formation in a mammal, the method comprising a step of administering to a subject an effective amount of a muramyl-dipeptide or a pharmaceutically acceptable salt thereof.
The foregoing summary is illustrative only and is not intended to be in any way limiting. Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Advantageous Effects
The present composition comprising muramyl-dipeptide can be advantageously used to prevent or treat bone related disease comprising osteoporosis. In contrast to the conventional therapeutic agents which are antiresorptive types of medications that slow bone loss by suppressing the function of osteoclast, the present composition is an anabolic type of drugs that increase the rate of bone formation by promoting the differentiation of osteoblasts and expression of regulatory genes that control the bone related genes and further the factors secreted from the osteoblasts that were increased by the present composition may further suppress the osteoclasts, thus preventing the bone loss due to osteoclasts without affecting the osteoclasts.
BRIEF DESCRIPTION OF THE DRAWINGS
These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is micrographs of osteoblast cell line MC4, primary osteoblasts derived from mouse calvaria and BMSCs, which were treated with various concentration of muramyl-dipeptide and then stained by detecting the alkaline phosphatase to assess the effect of the present muramyl-dipeptide on the differentiation of osteoblasts.
FIG. 2 is a result of RT-PCR of RNA extracted from MC4 cells treated with various concentration of muramyl-dipeptide for 6 hrs to assess the effect of the present muramyl-dipeptide on the expression of Runx2 at the mRNA level, which is essential for the differentiation of osteoblasts (upper part) and is a result of immunoblots using protein extracts from MC4 cells treated with muramyl-dipeptide for 24 hrs to assess the effect of the present muramyl-dipeptide on the expression of Runx2 at the protein level (lower part).
FIG. 3A is a graph showing the transcriptional activity of Runx2 in cells treated with the present muramyl-dipeptide using a reporter system which is under the control of Runx2 promoter.
FIG. 3B is a graph showing the transcriptional activity of Runx2 in cells treated with the present muramyl-dipeptide, L18-MDP or MTriLys using a reporter system which is under the control of Runx2 promoter.
FIG. 4 is 3D images of high-resolution micro-computed tomography (microCT) of femur from mice treated with the present muramyl-dipeptide to assess changes in trabecular bone volume in which the control group was treated with physiological saline and the experimental group was treated with the present muramyl-dipeptide.
FIG. 5 is graphs showing Trabecular thickness (Tb.Th) and Trabecular number (Tb.N) in mice treated with the present muramyl-dipeptide or physiological saline as a control, in which BV/TV represents bone volume and was calculated as % of Bone volume/Tissue volume.
FIG. 6 is micrographs of femur of the mice stained with H&E after treated with the present muramyl-dipeptide or treated with physiological saline as a control to assess the effect of MDP on bone formation.
FIG. 7 is results from macrophages derived from bone marrow and RANKL-primed osteoclasts treated with various concentrations of muramyl-dipeptide to assess the effect of the muramyl-dipeptide on the differentiation of osteoclasts.
FIG. 8 is graphs showing the bone volume of the mouse model treated with the present muramyl-dipeptide prior to the administration of GST-RANKL that is known to induce bone loss to assess the effect of the present muramyl-dipeptide on the bone loss.
DETAILED DESCRIPTION OF THE EMBODIMENT
The present disclosure is based on the findings that muramyl dipeptide (MDP) was able to promote the bone formation through its activity on osteoblasts with a relatively small amount and thus preventing the bone loss caused by osteoclasts, which were confirmed through various experiments to test its activities and efficacies on osteoblasts and experimental mice using MDP as shown in FIGS. 1 to 8 .
Therefore, in one aspect, the present disclosure relates to a pharmaceutical composition comprising muramyl-dipeptide, analog thereof, derivative thereof or a pharmaceutically acceptable salt thereof as an effective ingredient for preventing bone loss or promoting bone regeneration or bone formation.
The present composition comprising MDP functions as an anabolic type of drugs and is able to promote the bone formation or the bone regeneration by acting on osteoblasts. The present composition is differentiated from the conventional therapeutics which are antiresorptive type of medications that slow down bone loss by suppressing the function of osteoclast. Thus the present composition can be advantageously used for treating or preventing various bone disorders including for example, osteoporosis, bone damages caused by metastasis of cancer cells to bone, osteomalacia, rickets, osteitis fibrosa, adynamic bone disease, metabolic bone disease, osteolysis, leucopenia, bone deformity, hypercalcemia, rheumatoid arthritis, osteoarthritis, arthrosis deformans and nerve compression syndrome and the like.
Further, the present composition can also be advantageously used for preventing or treating diseases or conditions where the bone formation is suppressed. For example, the present composition is suitable for treating and/or preventing bone disorders associated with a systematic bone loss comprising such as osteogenesis imperfect, correction of malformation and orthodontics, implant accompanied by alveolar bone graft, and fracture and osteosynthesis, and for promoting local bone formation and bone regeneration for false joint and mixed bone graft.
In one embodiment, the present composition is particularly useful for treating or preventing osteoporosis.
Osteoporosis is classified into a primary and secondary osteoporosis. The primary osteoporosis is caused by a lack of calcium, vitamin D or suitable physical exercise or by smoking and also found in menopausal women and senescence men. The secondary osteoporosis, which may be developed in young people, is caused by a particular disorder or drug, in which the bone strength is decreased proportional to the drug exposure time or the severity of the disease or the drug. The disease which may cause osteoporosis includes hyperthyroidism, hyperparathyroidism, Cushing's symptom (hyperadrenocorticism), premature ovarian failure, menopause due to ovariectomy, hypogonadism, chronic liver disease (hepatocirrhosis), rheumatoid arthritis, chronic renal failure, gastrectomy and the like. The drug which may cause the secondary osteoporosis includes steroids (adrenocortical steroid), anticonvulsant (anticonvulsant), heparine and the like.
As used herein, the terms “treat,” “treatment,” and “treating” include alleviating, abating or ameliorating at least one symptom of a disease or condition of bone related disorder, and/or reducing severity, progression and/or duration thereof, and/or preventing additional symptoms, and includes prophylactic and/or therapeutic measures.
As used herein, the terms “prevent,” “prevention,” and “preventing” include the suppressing the development of the bone related disease or disorder by the administration of the present composition.
As used herein, the term “muramyl-dipeptide” is the shared structural unit of peptidoglycans from cell walls of both gram positive and gram negative bacteria. Peptidoglycan is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of all bacteria. The sugar component consists of alternating residues of β-(1,4) linked N-acetylglucosamine and N-acetylmuramic acid. Attached to the N-acetylmuramic acid is a peptide chain of three to five amino acids. Muramyl dipeptide is represented by formula 1 as below and is composed of N-acetyl muramic acid linked by its lactic acid moiety to the N-terminus of dipeptide, namely, an L-alanine D-isoglutamine.
wherein
R 1 is an acyl having 1 to 22 carbon atoms;
R 2 is an acyl having 1 to 22 carbon atoms;
R 3 is a lower alkyl having 1 to 4 carbon atoms;
R 4 is a hydrogen, an alkyl having 1 to 22 carbon atoms, a phenyl, or a phenyl-lower alkyl having a total of 6 to 15 carbon atoms, wherein the alkyl, phenyl and phenyl-lower alkyl may be substituted with one or more —OH, —OR 6 , —OC(O)R 6 , —C(O)R 6 , —NH 2 , —NHR 6 or —N(R 6 ) 2 groups, wherein R 6 is an alkyl having 1 to 4 carbon atoms;
R 5 is a hydrogen, an alkyl having 1 to 22 carbon atoms, a phenyl or a phenyl-lower alkyl having a total of 6 to 15 carbon atoms, wherein the alkyl, phenyl and phenyl-lower alkyl may be substituted with one or more —OH, —OR 6 , —OC(O)R 6 , —C(O)R 6 , —NH 2 , —NHR 6 or —N(R 6 ) 2 groups, wherein R 6 is an alkyl having 1 to 4 carbon atoms;
X is an aminoacyl selected from the group consisting of L-alanyl, L-tryptophanyl, L-valyl, L-lysyl, L-leucyl, L-ornithyl, L-isoleucyl, L-arginyl, L-α-aminobutyryl, L-histidinyl, L-seryl, L-glutamyl, L-threonyl, L-glutaminyl, L-methionyl, L-aspartyl, L-cysteinyl, L-asparaginyl, L-phenylalanyl, L-prolyl, L-tyrosyl and L-hydroxyprolyl; and
Y is a D-glutamic acid or D-aspartic acid, a (C 1-22 alkyl)ester thereof, a di(C 1-22 alkyl)ester thereof, an amide thereof, a (C 1-4 alkyl)amide thereof, a di(C 1-4 alkyl)amide thereof, or a (C 1-22 alkyl)ester-(C 1-4 alkyl)amide thereof.
As used herein the term, “alkyl” refers to a straight or branched monovalent hydrocarbon chain having 1 to 22 carbon atoms.
As used herein the term, “lower alkyl” refers to a straight or branched monovalent hydrocarbon chain having 1 to 4 carbon atoms.
As used herein the term, “acyl” refers to RC(O)— wherein R is a alkyl described as above.
As used herein the term, “aryl” refers to a phenyl or phenyl lower alkyl (for example benzyl) having 6 to 15 carbon atoms.
As used herein the term, “aminoacyl” refers to alpha amino acids having carbon atoms less than 12.
As used herein the term, “substitution” is a alkyl, acyl or aryl radical substituted with at least one of —OH, —OR 4 , —OC(O)R 6 , —C(O)R 6 , —NH 2 , —NHR 6 , or —N(R 6 ) 2 , in which R 6 is a lower alkyl described as above.
In one particular embodiment, R 1 , R 2 , R 4 and R 5 are each represented by a hydrogen, and R 3 is represented by a hydrogen or a methyl, X is L-alanyl, L-valyl, L-α-aminobutyryl, L-seryl or L-threonyl, Y is D-isoglutamine, D-aspartamine or D-asparagine.
In more particular embodiment, the present muramyl peptide includes but is not limited to N-acetylmuramyl-L-alanyl-D-isoglutamine, N-acetylmuramyl-L-alpha-aminobutyryl-D-isoglutamine, N-acetylmuramyl-L-valyl-D-isoglutamine, and N-acetylmuramyl-L-seryl-D-isoglutamine, N-acetylmuramyl-L-alanlyl-D-isoglutaminyl-N-stearoyl-L-lysine (MDP-L18), N-acetylglucosamyl-N-acetylmuramyldipeptide (GMDP) or Stearoyl-MDP derivatives.
Further MDP derivatives of the present disclosure include ones that are known in the art or can be prepared using the conventional methods known in the art, for example, EP 4,512, 2,677, JP 54/063016, 54/073729, 55/0192236, and U.S. Pat. Nos. 4,082,735, and 4,082,736. For example, the derivatives include but are not limited to, N-acetylmuramyl-L-alanine-D-isoglutamine-lysine, 6-O-stearoyl-N-acetylmuramyl-L-alanine-D-isoglutamine, acetylglucosamine-N-acetylmuramyl-L-alanine-D-isoglutamine, or acetylglucosamine-N-acetylmuramyl-L-alanine-D-isoglutamine-lysine and the like.
Also MDP which is included in the present composition may be synthesized by methods for example disclosed in J. M. Stewart and J. D. Young. Solid Phase Peptide Synthesis, 2nd ed., Pierce Chemical Co., Rockford, Ill. (1984); J. Meienhofer, Hormonal Proteins and Peptides, Vol. 2, Academic, New York, (1973) for the solid phase synthesis; and disclosed in E. Schroder amp; K. Lubke, The Peptides, Vol. 1, Academic Press, New York, (1965) for the liquid phase synthesis. Also Messer and Sinay, Biochem. Biophys. Res. Comm., 66, 1316 (1975) may be referred.
MDP included in the present disclosure has a structure that is simple to synthesize, or may be prepared from peptidoglycan which are extracted from cell walls of bacteria and treated with suitable enzymes followed by isolation and purification. Bacteria which may be useful for the production of MDP includes Escherichia coli and lactobacillus. Lactobacillus is particularly useful because it is a beneficial bacterium proven to be safe for human beings.
Pharmaceutical Compositions
The present muramyl dipeptide is useful for treating or preventing various bone disorders found in mammals which are associated with decreased bone mass. Particularly, the present composition is useful for treating or preventing osteoporosis.
In one aspect, the present disclosure relates to the use of muramyl dipeptide as an active ingredient for preparing compositions, particularly pharmaceutical compositions for bone regeneration or bone formation.
The present pharmaceutical composition comprises at least one pharmaceutically accepted carrier, excipients, binders, disintegrants, glidents, diluents, lubricants, colorants, sweetings, flavors, and/or antiseptics in addition to muramyl dipeptide as an active ingredient. The present pharmaceutical composition may be prepared using the conventional methods known in the art using the conventional solid or liquid types of carriers, excipients or diluents as described above.
The present composition comprising muramyl-dipeptide is suitable for administration by parenteral (for example, intravenous, subcutaneous, intramuscular administration), non-parenteral or inhaling route. Dosage forms include but are not limited to, for example, pills, tablets, film coated tablets, capsules, liposomes, micro- and nano-preparations, and powders and the like.
The present muramyl-dipeptide can also be used as a pharmaceutically acceptable salt thereof, which includes acid addition salts, alkali salts, or alkali earth metallic salts. For example, salts of Na, K, Li, Mg or Ca may be used
Pharmaceutically acceptable salts of the present MDP have the biological activity desired for the parent MDP without toxicity. Examples of such salts include (a) such as acid addition salts formed from inorganic acids such as HCl, Hydrobromic acid, Sulfuric acid, Phosphoric acid, or Nitric acid and the like; and salts formed from organic acids such as acetic acid, oxalic acid, tartar acid, succinic acid, maleic acid, fumaric acid, gluconic acid, citric acid, maleic acid, ascorbic acid, benzoic acid, tannin acid, pamoic acid, alginic acid, polyglutamic acid, naphthalenesulfonic acid, naphthalene, disulfonic acid, polygalacturonic acid and the like; (b) base addition salts formed from metallic polycation such as Calcium, Bismuth, Barium, Magnesium, Aluminum, Copper, Cobalt, Nickel, or Cadmium and the like; or base addition salts formed from organic cation such as N,N′-dibenzylethylenediamine or ethylenediamine; or (c) the combination of (a) and (b) such as zinc tannin salt.
The present composition may comprise about 5 to 95% by weight of MDP.
Examples of the pharmaceutically acceptable carriers, excipients or diluents include lactose, starch, sucrose, cellulose, magnesium stearate, calcium secondary phosphate, calcium sulfate, talc, mannitol and ethyl alcohol and the like. Also included in the present composition are binders, lubricants, disintegrants, cyroprotectants, lyoprotectants and sweetening agents, flavors and antiseptics if needed.
Binders refer to an agent that works as an adhesive and makes the powders bind or adhere to each other agglomerating them thus forming granules. Suitable binders include, but are not limited to, for example, sugars such as sucrose, starches derived from wheat, corn, rice or potato; natural gum, such as acacia, gelatin and tragacanth; derivatives from seaweed such as alginic acid, sodium alginate and calcium ammonium alginate; cellulose based materials such as methylcellulose and sodium carboxymethylcellulose and hydroxypropylmethyl-cellulose; polyvinyl pyrrolidone; and inorganic materials, such as magnesium aluminosilicate. Binders may be comprised in the present composition in an amount ranging from about 1% to about 30% by weight, particularly about 2% to about 20% by weight, more particularly about 3% to about 10% by weight, most particularly about 3% to about 6% by weight.
Diluents are materials that generally constitutes majority of formulations or compositions. Suitable diluents include, but are not limited to, for example, sugars, such as lactose, sucrose, mannitol and sorbitol; starches derived from wheat, corn, rice or potato, and cellulose, such as microcrystalline cellulose and the like. Diluents may be comprised in the present composition in an amount ranging from about 5% to about 95% by weight, particularly about 25% to about 75% by weight, more particularly about 30% to about 60% by weight, most particularly about 40% to about 50% by weight.
Disintegrating agents are materials that comprised in the formulation to promote the integration and thus release the effective ingredients in the composition. Suitable disintegrating agents include, but are not limited to, for example, starch, “soluble in cold water” modified starch, such as sodium carboxymethyl starch; natural or synthetic gums, such as locust bean, karaya, guar, tragacanth and agar, cellulose derivatives, such as methylcellulose and sodium carboxymethylcellulose, microcrystalline cellulose and cross-linked microcrystalline cellulose, such as croscarmellose sodium, alginate, such as alginic acid and sodium alginate, clay, such as bentonite and effervescent mixture and the like. Disintegrating agents may be comprised in the present composition in an amount ranging from about 1% to about 40% by weight, particularly about 2% to about 30% by weight, more particularly about 3% to about 20% by weight, most particularly about 5% to about 10% by weight.
Lubricants are materials that are used when making dosage forms such as tablets or granules to facilitate the release of such dosage forms from mouldings or dies. Lubricants are usually added just before the compression step of a process because they need to be present on and between the surface of dosage forms and press machine. Suitable lubricants include, but are not limited to, for example, metallic stearate, such as magnesium stearate, calcium stearate or potassium stearate; stearic acid; high melting point wax; and water soluble lubricant, such as sodium chloride, sodium benzoate, sodium acetate, sodium oleate, polyethylene glycol and the like. Lubricants may be comprised in the present composition in an amount ranging from about 0.05% to about 15% by weight, particularly about 0.2% to about 5% by weight, more particularly about 0.3% to about 3% by weight, most particularly about 0.3% to about 1.5% by weight.
Glidents are materials that are used to prevent caking and to increase flowability of the granules. Suitable glidents include, but are not limited to, for example, silicon dioxide and talc. Glidents may be comprised in the present composition in an amount ranging from about 0.01% to about 10% by weight, particularly about 0.1% to about 7% by weight, more particularly about 0.2% to about 5% by weight, most particularly about 0.5% to about 2% by weight.
Coloring agents are excipients that are used to color the formulations or compositions. Suitable coloring agents include, but are not limited to, for example, food grade dyes and suitable adsorbent, such as clay or aluminum oxide. The coloring agents may be comprised in the present composition in an amount ranging from about 0.01% to about 10% by weight, particularly about 0.05% to about 6% by weight, more particularly about 0.1% to about 4% by weight, most particularly about 0.1% to about 1% by weight.
The present composition may be formulated for a sustained and controlled release of at least one of the ingredients or active ingredients. Suitable sustained release formulation include a controlled release polymer matrix formulated as a tablet or a capsule comprising porous polymer matrix capsuled or impregnated with an active ingredient or a layered tablet comprising layers regulating the rate of disintegration.
The liquid formulation of the present composition may comprise a solution, a suspension and an emulsion. The liquid formulation may comprise a solution for nasal administration or a buffering agent.
Buffering agents are added to a solution to regulate pH of the solution and to maintain it within certain ranges when acids or alkali is added to the solution or the solution is diluted with a solvent. Buffering agents with effective pH range of 2.7 to 8.5, more particularly pH ranges of 3.8 to 7.7 are preferred. Examples of such buffering agents which are suitable for administration to the patients include but are not limited to, acetate, carbonate, citrate, fumarate, glutamate, lactate, phosphate, phthalate and succinate.
Further, for the preparation of the formulation and administration of the present composition, the latest edition of “Remington's Pharmaceutical Sciences” [Mack Publishing Co., Easton Pa.] may be referred.
Health Functional Food
In other aspect, the present disclosure relates to a use of the present MDP for foods, such as functional foods, health functional foods, supplemental health products, or food additives.
As used herein the term “foods” refer to a natural or processed products containing at least one nutrients, particularly which are processed enough to be ingested without further process, and which include in general terms, foods, functional foods, health functional foods, supplemental health products, food additives and drinks.
As used herein the term “functional foods” refer to a group of foods given an additional function particularly related to health promotion or disease prevention by a physical, biochemical, or biotechnological process or refer to a processed food designed to be utilized in the body to support defense mechanism, disease prevention or recovery. Particularly it includes health functional foods.
As used herein “supplemental health foods” refer to a processed food manufactured using a raw material or ingredient having a function or activity beneficial to the body. Particularly it is a processed food prepared by extraction, concentration, purification and mixing of the nutrients or ingredients contained in the food or prepared using a certain raw material with intention to provide nutrients or some health benefit.
Health functional foods comprising the present composition or MDP may be used to prevent or benefit bone related disease such as osteoporosis and may be prepared various methods known in the related art such as food science or pharmacology. The health functional foods may be formulated as tablets, capsules, soft gels, gel caps, liquids, or powders for oral administration with or without sitologically acceptable carriers, excipients or diluents and the like.
For the administration of the health function foods, oral route is preferred. Further the present health functional foods may be advantageously used for women before and after the menopause, but the subject is not limited thereto.
The present health function foods may further comprise sitologically acceptable food additives. For example, various flavoring agents or natural carbohydrates may be used and the amount to be included may be determined according to what is known in the art. Examples of carbohydrates include a monosaccharide such as glucose, and fructose; a disaccharide such as maltose and sucrose and the like; polysaccharides such as dextrin and cyclodextrin and sugar alcohols such as xylitol, sorbitol, erythritol and the like. Examples of flavoring agents include natural flavoring agents (tau Martin, stevia extract (e.g., seed video Les Bauer A, Glee Shire gonna push, etc)) and synthetic flavoring agents (saccharine, aspartame and the like).
The present health function foods may further comprise various nutrients, vitamins, minerals (electrolyte), synthetic and natural flavors, colorants, pectic acids and salts thereof, alginates and salts thereof, organic acids, protective colloidal thickenings, pH adjusting agents, stabilizers, antiseptics, glycerin, alcohols, and carbonation agents for carbonated liquid.
The components as described above may be used separately or in combinations thereof.
The present health function foods may comprises MDP as an active ingredient in a suitable amount which varies and may be selected depending on or considering age, sex, body weight of the subject to be treated for osteoporosis or a related condition or state. Particularly an amount in the range of 0.01 g to 10.0 g for an adult per day is included in the composition. However, the amount to be used or included in the foods may be various and suitably selected depending on or considering the purpose (preventing or improving). Further when the present health function foods are used for a long term basis, the amount can be adjusted accordingly.
Methods for Promoting Bone Regeneration or Bone Formation.
Also embodied in the present disclosure is a method of treating bone disorders by administering to a subject in need thereof an effective amount of the present composition comprising MDP. The bone disorders includes osteoporosis, bone damages caused by metastasis of cancer cells to bone, osteomalacia, rickets, osteitis fibrosa, adynamic bone disease, metabolic bone disease, osteolysis, leucopenia, bone deformity, hypercalcemia, rheumatoid arthritis, osteoarthritis, arthrosis deformans and nerve compression syndrome and the like. Further, the present composition can also be advantageously used for preventing or treating diseases or conditions where the bone formation is suppressed. For example, the present composition is suitable for treating and/or preventing bone disorder associated with systematic bone loss comprising such as osteogenesis imperfect, correction of malformation and orthodontics, implant accompanied by alveolar bone graft, and fracture and osteosynthesis, and for promoting local bone formation and bone regeneration for false joint and mixed bone graft.
In the present methods the composition is administered in an effective amount that is enough to “prevent” or “treating” the disease as described above so that the disease is cured, prevented, suppressed or retarded.
As used herein the term “subject” or “patient” refers to a mammal to which the present composition may be administered for a desired effect, and includes particularly a human being and non-human primates.
The present MDP is apt for a combination therapy with other therapeutic agents to treat or prevent bone disorders. Such combination therapy refers to the administration of the present composition prior to, simultaneously with or after the administration of a therapeutic agent.
The present disclosure is further explained in more detail with reference to the following examples. These examples, however, should not be interpreted as limiting the scope of the present invention in any manner.
EXAMPLES
Example 1: The Effect of MDP on the Differentiation of Osteoblasts
N-acetylmuramyl-L-Alanyl-D-Isoglutamine commercially available from Invivogen Inc. was dissolved in endotoxin free purified water to make a solution of 5 mg/ml. To assess the effect of muramyl dipeptide on the differentiation of osteoblast, osteoblast cell line MC4 cells (ATCC CRL-2593:MC3T3-E1 Subclone 4) were incubated in an ascorbic acid free-αMEM medium containing 10% fetal bovine serum, 50 unit/ml penicillin, 50 μg/ml streptomycin at 37° C. under 100% humidity and 5% CO 2 atmosphere. The medium was changed every 3 days.
Then MC4 cells were seeded onto each well of a 48 well plate at the concentration of 20,000 cells/well and then after 16 hrs, each well was treated for 5 days with 400 μl of 0, 0.1, 1 and 10 μg/ml of MDP as prepared above in the differentiation medium (50 μg/ml ascorbic acid and 10 mM beta-glycerophosphate containing αMEM), during which half of the medium was changed twice with the differentiation medium. The effect on the differentiation was analyzed using alkaline phosphatase (ALP) staining. Results are shown in FIG. 1 , in which the effect on the differentiation was determined by the number of cells showing red-purple color as well as the intensity of the color. FIG. 1 shows that the differentiation of MC4 was increased in a concentration dependent manner. Also when BMSC (bone marrow stem cells) derived from mouse and primary OB (osteoblast derived from mouse calvaria) were used instead of MC4 and tested under the same condition, similar results were obtained as shown in FIG. 1 . Each experiment was repeated at least 3 times.
Example 2: The Effect of MDP on the Expression of Genes Involved in the Differentiation of Osteoblasts
Example 2-1: The Effect of MDP on the Expression of Runx2 Gene at mRNA and Protein Level
Runx2 (Runt-related transcription factor 2) is an essential gene for the differentiation of osteoblast, skeletal morphogenesis and functions as a scaffold for nucleic acids and regulatory factors involved in the expression of skeletal genes. Thus, it is known that the absence of Runx2 leads to lack of bone formation. Therefore the following experiments were performed using Runx2 as a differentiation indicator to examine the effect of MDP on the expression of Runx2 gene.
Firstly, MC4 cells as described in Example 1 were treated with various concentrations of MDP as indicated in FIG. 2 for 6 hrs. Then, total mRNA was extracted from the cells and incubated with random primer at 70° C. for 5 min. After that reverse transcriptase, buffer for RT and dNTPs were added to the reaction mixture and incubated at 42° C. for 1 hr to synthesize cDNA, which was then used as a template for PCR to amplify Runx2 using specific primers as described in Table 1 and using the following condition: cDNA was initially denatured at 94° C. for 5 min followed by 25 cycles at 95° C. for 40 s, 59° C. for 40 s, and 72° C. for 40 s and final extension for 5 min at 72° C. As shown in FIG. 2 (upper part) the mRNA expression of Runx2 was found to be increased after MDP treatment in a concentration dependent manner. The results were normalized relative to β-actin data.
TABLE 1
Forward primer
Reverse primer
Runx2
CCG CAC GAC AAC CGC ACC AT
CGC TCC GGG CCA CAA ATC TC
β-actin
GTG GGG CGC CCC AGG CAC CA
CTC CTT AAT CTC ACG CAC GAT TTC
Also to examine the effect at the protein level, whole cell extract was prepared from the cells treated with MDP for 24 hrs as described above, and 40 μg of extract was used for SDS-PAGE electrophoresis. Then the gel was transferred to a PVDF membrane and immunoblot was performed using an antibody specific to Runx2 (Abcam, USA). As shown in FIG. 2 (lower part), MDP increased the expression of Runx2 protein. The β-actin was used as a loading control.
Further to examine whether the increased expression of Runx2, which is a transcription factor, affects the expression of other genes regulated by Runx2, the following experiments were performed. For this, MC4 cells were seeded onto each well of a 96 well plate at the concentration of 20,000 cells/well and the cells were transfected with a plasmid 6XOSE/Luc reporter vector (Journal of Biological Chemistry. 285: 3568-3574 (2010)) which expresses luciferase gene under the control of osteocalcin using Lipofectamin® (Life technologies, Inc) according to the manufacturer's instruction. The promoter in the plasmid contains five motifs to each of which Runx2 binds. By binding of Runx2 to the motif, the expression of luciferase increases. After 16 hrs after the transfection, MDP at the concentration as indicated in FIG. 3 was added to the cells. After 24 hrs, the cells were lysed and the luciferase activity was measured using Luciferase detection kit (Promega, USA) according to the manufacturer's instruction to quantify the mRNA level of osteocalcin gene, which is affected by Runx2. As shown in FIG. 3A , muramyl dipeptide increased the expression of Runx2, which then increased the transcription of osteocalcin.
Example 2-2: The Effect of Derivative of Muramyl Dipeptide on the Transcriptional Activity of Runx2
In addition to MDP as used in Example 2-1, as a derivative thereof, M-TriLYS (MurNAc-Ala-D-isoGln-Lys, N-acetylmuramyl-L-alanine-D-isoglutamine-lysine) and 6-O-stearoyl-N-acetylmuramyl-L-alanyl-D-isoglutamine (L18-MDP) were used to examine the effect of the derivatives on the expression of Runx2 at transcription level. M-TriLYS is a muropeptide obtainable from peptidoglycans of lactobacillus or salivarius and contains in its structure muramyl dipeptide. L18-MDP is a MDP derivative containing C18 fatty acid.
As shown in FIG. 3B , similar results were obtained using MDP, MTnLYS and L18-MDP, all of which increased the expression of Runx2 at the transcriptional level. Notably, L18-MDP showed the activity on Runx2 10 times higher than that of MDP. These results indicate that not only MDP but also its derivatives can be effective for the desired effects.
Example 3: Evaluation of Bone Formation in Mice
Example 3-1: Experimental Mice
Six-week-old WT C57BL/6 (B6) mice were purchased from Orient Company Ltd (Seoul, Korea). The animals were maintained at a controlled temperature (21±1° C.) and humidity (55±1%) with a 12/12-h light-dark cycle without any restriction of food and water. All animal experiments were performed following the protocol approved by the Institutional Animal Care and Use Committee of CRISNUH.
Example 3-2: Administration of Test Material
To each mouse, 1.25 mg/kg of MDP prepared as described in Example 1 was administered twice with a 4 day interval by intraperitoneal injection. Physiological saline was used as a control. The second injection was given 4 days after the first injection and after 3 days the mice were sacrificed and used for bone volume analysis.
Example 3-3: Determination of Bone Volume
A right femur was removed from the sacrificed mouse and stripped of the muscle. The excised femur was then fixed in 10% of neutral formalin for one day at the least, which was then analyzed for bone volume using microCT. MicroCT data showing a 3D histological image based on the measured bone volume are shown in FIG. 4 , in which the mice treated with muramyl dipeptide showed an increase in bone volume compared to the control treated with physiological saline. Also as in FIG. 5 , both Trabecular thickness (Tb.Th) and Trabecular number (Tb.N) as well as Trabecular bone volume were shown to be increased statistically significantly in the mice treated with MDP compared to the control. In FIG. 5 , BV/TV=Bone volume/Tissue volume=% bone volume.
Example 3-4: Histological Observation
The femur used for the analysis of bone volume in Example 3-3 was used for a histological observation. For this, the femur was demineralized in 10% EDTA for 7 days and washed with running water for 12 hrs in a tissue capsule. After that, the femur was treated with alcohol and xylene and embedded in paraffin, from which sections having a thickness of 4 μm were prepared. The sections were then placed on a slide glass and deparaffinized at 65° C. for 30 min and treated with Hematoxylin and Eosin according to the conventional method.
The slides were then examined with a light microscope to observe the bone formation. As shown in FIG. 6 , more spongy bone was observed in the mice treated with MDP compared with the control treated with physiological saline. This indicates the increase in bone volume by the administration of MDP.
Example 4: The Effect of Muramyl Dipeptide on the Differentiation into Osteoclasts
Bone marrow cells (BMs) were isolated from the long bones of mouse and were cultured in α-MEM supplemented with 10% FBS, 100 U/ml penicillin and 100 μg/ml streptomycin, and 2 ng/ml M-CSF for 1 day. Suspended cells were differentiated into BMMs with 20 ng/ml M-CSF for 3 days. The BMMs were incubated with 20 ng/ml M-CSF and 20 ng/ml RANKL in the presence or absence of MDP for additional 3 days. To make RANKL-primed osteoclast precursors, the BMMs were stimulated with 20 ng/ml mouse RANKL for 48 h. The BMMs were incubated with 20 ng/ml M-CSF in the presence or absence of MDP for additional 3 days.
The differentiation was determined by tartrate resistant acid phosphatase (TRAP) staining using Leukocyte acid phosphate-staining kit (Sigma-Aldrich Chemical, USA) according to the manufacturer's instruction. After the staining, TRAP-positive multinucleated cells with at least 3 nuclei were enumerated as mature osteoclasts with an inverted phase-contrast microscope and results are shown in FIG. 7 .
As shown in FIG. 7 , it was found that muramyl dipeptide did not affect the differentiation into osteoclast from bone marrow macrophages. Also Muramyl dipeptide did not affect osteoclast differentiation from RANKL-primed osteoclast precursors which is TRAP-positive mononucleated cells ( FIG. 7 , Right graph). In contrast it was shown that MDP indirectly alleviated osteoclast differentiation through up-regulation of Osteoprotegerin (OPG), also known as osteoclastogenesis inhibitory factor (OCIF), and down-regulation of RANKL in the osteoblast (data not shown).
These results indicate that muramyl dipeptide do not directly but indirectly affect the differentiation of the cells into osteoclasts. Thus the present composition can be advantageously used for increasing the bone formation and also for preventing bone loss by osteoclasts.
Example 5: In Vivo Effect of Muramyl Dipeptide on the Prevention of Osteoclasia Using a Mouse Model
Muramyl dipeptide was administered to a mouse by an intraperitoneal injection two times with four day interval between the administration at the concentration of 1.25 mg/kg. After 3 days of the administration, GST-RANKL recombinant protein was intraperitoneally administered at the concentration of 1 mg/kg three times with a 24 hr interval between the administrations, The bone volume was analyzed at 1 day after the last administrated with GST-RANKL. The recombinant protein was prepared using a RANKL expression vector, pGEX-GST-RANKL (J. Clin Invest. 106:1481-1488 (2000)), which was expressed in E. coli and the protein was purified using a sepharose gel attached with glutathione (glutathione-sepharose gels, Sigma-Aldrich). The purified protein was then treated with Detoxi-gel endotoxin removing gel (Thermo Scientific, USA) to remove endotoxin and used for the experiment. Seven days after the administration, mice were sacrificed and the bone volume was measured using a microCT. As controls, mice treated only with physiological saline, GST-RANKL or physiological saline and GST-RANKL in a consecutive order were used.
As shown in FIG. 8 , when the mice were pretreated with muramyl dipeptide, the bone loss due to GST-RANKL was reduced compared to the controls in which the mice was not pretreated with muramyl dipeptide before the GST-RNAKL administration.
These results indicate the effect of muramyl dipeptide on the prevention of bone loss.
While the present invention has been shown and described in terms of various aspects, it will be apparent to those skilled in the art that various modification and changes may be made without departing the principles and spirit of the invention. Thus the scope of the invention must be defined by the appended claims and their equivalents.
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or form the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
Unless defined otherwise, all technical and scientific terms and any acronyms used herein have the same meanings as commonly understood by one of ordinary skill in the art in the field of the invention. Although any methods and materials similar or equivalent to those described herein can be used in the practice of the present invention, the preferred methods, devices, and materials are described herein.
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The present invention relates to a bone regeneration or bone formation promoting pharmaceutical composition comprising muramyl dipeptide, an analog thereof, a derivative thereof or a pharmaceutically acceptable salt thereof. In contrast to existing passive therapeutic agents which center on bone absorption suppression based on mechanisms for reducing osteoclast functionality, the composition comprising muramyl dipeptide of the present invention promotes the differentiation of osteoblasts, which are bone forming cells, and can advantageously be used in various diseases where bone formation is required as an active therapeutic agent that does not affect osteoclast.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 10/963,222 filed on Oct. 12, 2004, now U.S. Pat. No. ______, which claims the benefit of U.S. Provisional Application No. 60/512,173, filed Oct. 17, 2003, both of which are incorporated herein.
BACKGROUND
[0002] The invention relates to incorporating a viscous component in an effervescent composition.
[0003] Viscous materials are difficult to formulate into a homogeneous effervescent composition that is easy to handle and package. In particular, viscous materials can cause aggregation, which impairs the formation of a free flowing effervescent powder. Viscous materials also stick to the equipment that is used to process effervescent compositions including the tablet presses that are used to mass-produce tablets. Attempts to form tablets from compositions that include viscous agents can produce deformed tablets that lack structural integrity.
SUMMARY
[0004] In one aspect, the invention features a method of making an effervescent composition, the method including heating a viscous component to a temperature of at least 45° C., the viscous component exhibiting a viscosity greater than 50,000 cps at 23° C. and 1 sec −1 and a viscosity less than 5000 cps at a temperature of at least 38° C. and 1 sec −1 , heating a composition including an effervescent agent to a temperature of at least 45° C., and combining the heated viscous component and the heated composition. In one embodiment, the viscous component is selected from the group consisting of honey, molasses, wax and combinations thereof. In other embodiments, the viscous component includes hop extract. In another embodiment, the viscous component includes kava.
[0005] In one embodiment, the effervescent composition includes from 5% by weight to 30% by weight of the viscous component. In another embodiment, the effervescent composition includes from about 5% by weight to about 25% by weight of the viscous component. In other embodiments, the effervescent composition includes from about 10% by weight to about 20% by weight the viscous component.
[0006] In some embodiments, the effervescent composition further includes a flow agent. In one embodiment, the flow agent is selected from the group consisting of silica, fumed silica, precipitated silica, magnesium oxide, calcium phosphate, magnesium carbonate, calcium silicate, sodium alumino silicate, and combinations thereof.
[0007] In other embodiments, the effervescent composition includes from 3% by weight to 20% by weight silica, or even from 5% by weight to 15% by weight silica.
[0008] In another aspect, the invention features a method of making a free flowing powder that includes an effervescent composition disclosed herein.
[0009] In other aspects, the invention features a method of making an effervescent tablet, the method including making an effervescent composition, and tableting the effervescent composition. In one embodiment, the tableting includes forming a tablet having a hardness of from 3 Kp to 15 Kp. In other embodiments, the tablet includes from 5% by weight to 30% by weight of the viscous component. In some embodiments, the tablet includes from about 10% by weight to about 20% by weight of the viscous component.
[0010] In another embodiment, the tablet further includes binder and lubricant.
[0011] In one embodiment, the method of making an effervescent composition, includes heating a viscous component having a viscosity greater than 50,000 cps at 23° C. to a temperature sufficient to cause the component to exhibit a viscosity no greater than 5000 cps, heating a composition including an effervescent agent to a temperature of at least 45° C., and combining the component and the heated effervescent agent to form an effervescent composition.
[0012] In another aspect, the invention features an effervescent composition that includes a viscous component exhibiting a viscosity greater than 50,000 cps at 23° C. and 1 sec −1 and no greater than 5000 cps at a temperature of at least 38° C. and 1 sec −1 , effervescent agent, and silica, the effervescent composition being a uniform, free-flowing granulation. In some embodiments, the effervescent composition includes from 3% by weight to 20% by weight silica.
[0013] In another embodiment, the effervescent composition includes a viscous component exhibiting a viscosity greater than 50,000 cps at 1 sec −1 and 23° C. and a viscosity less than 5000 cps at 10 sec −1 and a temperature of at least 55° C., and effervescent agent. In one embodiment, the viscous component is solid at 23° C. In another embodiment, the effervescent composition is a uniform, free-flowing granulation. In some embodiments, the effervescent composition includes from 5% by weight to 30% by weight the viscous component, from about 5% by weight to about 25% by weight of the viscous component, or even from about 10% by weight to about 20% by weight of the viscous component. In some embodiments, the effervescent composition includes a flow agent selected from the group consisting of silica, fumed silica, precipitated silica, magnesium oxide, calcium phosphate, magnesium carbonate, calcium silicate, sodium alumino silicate, and combinations thereof.
[0014] In some embodiments, an effervescent composition described herein is in the form of a tablet. In one embodiment, the composition of the tablet further includes binder, lubricant, or a combination thereof. In another embodiment, the effervescent composition described herein is in the form of a free flowing powder. In another embodiments, an effervescent composition described herein includes an effervescent agent that includes citric acid and sodium bicarbonate, and further includes silica, lactose, magnesium stearate, and sorbitol.
[0015] In another aspect, the invention features a method of using an effervescent composition described herein, the method including adding the effervescent composition to an aqueous liquid.
[0016] The invention features a method of incorporating a viscous component in an effervescent composition. The effervescent composition provides a viscous component in a predetermined amount and in a convenient form that is easy to handle.
[0017] The invention also features an effervescent composition that is capable of being tableted in an automated process and forming a tablet that exhibits good structural integrity.
[0018] The effervescent composition can be formulated to readily disperse in aqueous-based compositions. The effervescent composition can be formulated to disperse the viscous component in water at a rate that is faster relative to the rate of dispersion of the viscous component alone.
[0019] Other features and advantages will be apparent from the following description of the preferred embodiments and from the claims.
GLOSSARY
[0020] In reference to the invention, these terms have the meanings set forth below:
[0021] The term “effervescent composition” refers to a composition that evolves a gas (e.g., carbon dioxide) when placed in an aqueous liquid.
[0022] The term “viscous component” refers to a component that is any one of a solid, semisolid and liquid at room temperature.
DETAILED DESCRIPTION
[0023] The effervescent composition includes a viscous component, and an effervescent agent. The viscous component is a solid, semisolid or has a viscosity of at least 50,000 centipoise (cps), at least 100,000 cps, or even at least 300,000 cps, at room temperature (i.e., from 68° F. to 77° F. (20° C. to 25° C.), and is a pourable liquid when heated to an elevated temperature. Preferably the viscous component exhibits a viscosity no greater than 5000 cps, or even no greater than 3000 cps at a temperature of at least 40° C., at least 55° C., or even at least 60° C., when measured at 10 second −1 (reciprocal second), or even 1 sec −1 .
[0024] Suitable viscous components include Newtonian and non-Newtonian compounds including, e.g., honey, molasses, wax, hop extract, kava, and mixtures thereof. A suitable hop extract is available under the trade designation YC Enhanced Oil hop extract from Yakima Chief, Inc. (Sunnyside, Wash.), one lot of which was found to have a viscosity of 54,000 cps at 23° C. and 1 sec −1 and 8,400 cps at 23° C. and 10 sec −1 and 2,900 at 40° C. and 1 sec −1 and 700 cps at 40° C. and 10 sec −1 . The viscous component is present in the effervescent composition in an amount suitable for its intended purpose. Useful formulations include a viscous component in an amount of at least 1% by weight, from about 5% by weight to about 30% by weight, from about 5% by weight to about 25% by weight, or even from about 10% by weight to about 20% by weight.
[0025] The effervescent agent preferably is at least one component of an effervescent couple that includes an acid and a base. The effervescent couple is activated when contacted with water, e.g., when the tablet is placed in a glass of water. The water liberates the acid and base and enables the acid and base to react with each other to produce carbon dioxide gas, which imparts carbonation to the aqueous composition. At least one component of the effervescent couple can also be an active agent. Examples of useful acids include citric acid, ascorbic acid, malic acid, adipic acid, tartaric acid, fumaric, succinic acid, sodium acid pyrophosphate, lactic acid, hexamic acid, and acid salts and acid anhydrides thereof, and mixtures thereof. Examples of useful acid anhydrides include citraconic anhydride, glucono-D-lactone, and succinic anhydride. Examples of useful acid salts include potassium bitartrate, acid citrate salts, sodium dihydrogen phosphate, disodium dihydrogen phosphate, sodium acid sulfite, and combinations thereof. Acid is present in the composition in an amount of from 5% by weight to about 60% by weight, from about 5% by weight to about 30% by weight, or even from about 10% by weight to about 20% by weight.
[0026] The base preferably is capable of generating carbon dioxide. Examples of suitable carbonate bases include sodium bicarbonate, sodium carbonate, sodium sesquicarbonate, potassium carbonate, potassium bicarbonate, calcium carbonate, magnesium carbonate, magnesium oxide, sodium glycine carbonate, L-lysine carbonate, arginine carbonate, zinc carbonate, zinc oxide and mixtures thereof. The base is present in the composition in an amount of from 10% by weight to about 60% by weight, from about 20% by weight to about 50% by weight, or even from about 30% by weight to about 45% by weight.
[0027] The effervescent composition preferably includes a flow agent. The flow agent preferably enhances the ability of the effervescent composition to flow through the components of a manufacturing operation including, e.g., the components of an automated tableting operation (e.g., a hopper and a tablet press). Suitable flow agents include, e.g., silica (e.g., fumed silica and precipitated silica), magnesium oxide, calcium phosphates (e.g., mono-, di- and tri-calcium phosphates), magnesium carbonate, calcium silicate, sodium alumino silicates, and combinations thereof. A useful fumed silica is commercially available under the trade designation CAB-O-SIL from Cabot Corp. (Boston, Mass.). The flow agent is preferably present in the composition in an amount of at least 0.5% by weight, from about 3% by weight to about 20% by weight, or even from about 5% by weight to about 15% by weight.
[0028] The effervescent composition can be in a variety of forms including, e.g., powder (e.g., a free flowing granulation), tablet, capsule, and pellet. The effervescent composition can be prepared to exhibit a desired dissolution rate. Useful effervescent tablets include effervescent tablets having a hardness of at least 3 kilopounds (Kp), at least 4 Kp, from about 5 Kp to about 15 Kp, or even from about 5 Kp to about 10 Kp, as measured on a standard hardness tester fitted with a strain gauge. In one embodiment, the tablets are formulated to weigh about 5000 mg and preferably dissolve in excess boiling water in less than 300 seconds, less than 100 second, or even less than 60 seconds.
[0029] When in the form of a tablet or capsule, the composition preferably includes binder, lubricant, and combinations thereof. Examples of suitable binders include, e.g., starches, natural gums, cellulose gums, microcrystalline cellulose, methylcellulose, cellulose ethers, sodium carboxymethylcellulose, ethylcellulose, gelatin, dextrose, lactose, sucrose, sorbitol, mannitol, polyethylene glycol, polyvinylpyrrolidone, pectins, alginates, polyacrylamides, polyvinyloxoazolidone, polyvinylalcohols and mixtures thereof.
[0030] The effervescent composition includes a sufficient amount of binder to assist in holding the components of the composition together in the form of a tablet. Preferably binder is present in the composition in an amount of from 10% by weight to about 60% by weight, from about 15% by weight to about 50% by weight, or even from about 25% by weight to about 40% by weight.
[0031] Various lubricants are suitable including water dispersible, water soluble, water insoluble lubricants and combinations thereof. Preferred lubricants are water soluble. Examples of useful water soluble lubricants include sodium benzoate, polyethylene glycol, L-leucine, adipic acid, and combinations thereof. The composition can also include water insoluble lubricants including, e.g., stearates (e.g., magnesium stearate, calcium stearate and zinc stearate), oils (e.g., mineral oil, hydrogenated and partially hydrogenated vegetable oils, and cotton seed oil) and combinations thereof. Other water insoluble lubricants include, e.g., animal fats, polyoxyethylene monostearate, talc, and combinations thereof.
[0032] The effervescent composition preferably includes a sufficient amount of lubricant to enable the composition to be formed into tablets and released from a high speed automated tableting press in the form of a tablet. The effervescent composition preferably includes water soluble lubricant in an amount of from 0.1% by weight to about 15% by weight, from about 0.1% by weight to about 10% by weight, from about 0.5% by weight to about 5% by weight, or even from about 0.5% by weight to about 3% by weight.
[0033] The effervescent composition can also include water insoluble lubricants. Preferably effervescent composition includes less than 3% by weight water insoluble lubricants.
[0034] The effervescent composition can also include other ingredients including, e.g., flavor agents, fillers, surfactants (e.g., polysorbate 80 and sodium lauryl sulfate), color agents including, e.g., dyes and pigments, sweetening agents, and combinations thereof.
[0035] In preparing the effervescent composition at least some of the components are preferably heated to a temperature of at least 40° C., from 40° C. to 70° C., or even from 45° C. to 65° C., prior to being combined with one or more of the other components of the effervescent composition. In some embodiments, the viscous component is stirred (e.g., subjected to a shear stress) prior to combination with another component of the effervescent composition.
[0036] The effervescent composition is preferably stored in a moisture-proof package e.g., sealed foil containers (e.g., bags and pouches), sealed plastic bags, blister packs, desiccant capped tubes, and combinations thereof. A number of tablets or capsules can be placed in a single package.
[0037] The effervescent composition can be formulated for use in a variety of applications including, e.g., dispersing in an aqueous-based composition (e.g., water) at a variety of temperatures (e.g., refrigerated, room temperature, and boiling (e.g., boiling water)).
[0038] The invention will now be described by way of the following examples.
EXAMPLES
Test Procedures
[0039] Test procedures used in the examples include the following.
Viscosity
[0040] The viscosity measurement is obtained using a Haake RS100 controlled stress rheometer (Haake). The rheometer is set up with a parallel plate measuring system in which the bottom plate is fixed and the temperature of the sample is controlled using a TC-81 Peltier temperature controller. The upper plate is 35 mm diameter and is rotated at a programmed ramp from 0 sec −1 to 50 sec −1 shear rate and then from 50 sec −1 to 0 sec −1 shear rate. The sample is tested by placing a from 2 to 3 cubic centimeters of sample on the bottom plate and raising the bottom plate until the gap to the upper plate is 2 mm. The sample completely fills the gap between the two plates and excess is carefully scraped away. The samples are equilibrated to the specified temperature before the measurement is obtained. A solvent trap apparatus is employed to minimize evaporation at higher temperatures. Viscosity values are determined during the ramp down from 50 sec −1 to 0 sec −1 at shear rates of 1 sec −1 and 10 sec −1 .
Example 1
[0041] The effervescent composition of Example 1, which included hops extract having a viscosity of 54,000 cps at 23° C. and 1 sec −1 and 8,400 cps at 23° C. and 10 sec −1 and 2,900 at 40° C. and 1 sec −1 and 700 cps at 40° C. and 10 sec −1 , was prepared as follows. Into a first container was blended 29.7 kg anhydrous citric acid fine granular 50 USP/FCC, and 26.4 kg instant sorbitol FGPh, and 2,200 g magnesium stearate. Into a second container was blended 37.4 kg sodium carbonate (Grade 50), 37.4 kg sodium carbonate (Grade 100), 7,700 g sodium bicarbonate No. 5, and 28.6 kg FAST-FLO spray dried modified lactose monohydrate (#316 NF) Foremost Farms (Rothschild, Wis.). The first and second containers were placed in an oven, preheated to 50° C.+/−2° C., for at least 14 hours prior to further compounding.
[0042] The heated contents of the second container were added to a ribbon blender, which had been preheated to 50° C.+/−2° C. using belt heaters, followed by the addition of 15.4 kg CAB-O-SIL fumed silicon dioxide (Cabot Corp., Boston, Mass.), and then the contents of the first container. The components were blended for 30 minutes with the cover of the blender closed. Then 35.2 kg YC Enhanced Oil hop extract (Yakima Chief, Inc., Sunnyside, Wash.), which had been warmed in a warming vessel, was added slowly to the ribbon blender. The mixture was blended for from about 30 to 60 minutes.
[0043] The resulting composition was a uniform, free-flowing granulation that did not stick to the sides of the blender.
[0044] The effervescent composition was then transferred to a tablet press having a one inch tool to form tablets weighing from approximately 4.75 g to 5.25 g. The tablets were pressed to a hardness of from 3 Kp to 9 Kp.
[0045] The tablets had an average weight of 5.02 g, a thickness of 0.256 inch, and a hardness of 7.0 Kp.
[0046] Two tablets were then placed in 200 mL of boiling water and were observed to completely dissolve in 163 seconds.
Example 2
[0047] An effervescent composition including kava was prepared by adding 137.5 g kava extract containing stevia (the kava had a viscosity of 14,000 cps at 55° C. and 1 sec −1 and 4,500 cps at 55° C. and 10 sec −1 ), which had been preheated to a temperature of 60° C., to a composition that had been preheated to 60° C. and included 467.5 g sodium carbonate #100, 220 g citric acid, 165.0 g FASTFLO spray dried modified lactose monohydrate (#316 NF) Foremost Farms (Rothschild, Wis.), 220 g sorbitol, 103.1 g CAB-O-SIL silicon dioxide (Cabot Corp., Boston, Mass.), 48.1 g sodium bicarbonate #5, and 13.8 g magnesium stearate. The kava was added to the mixture over a period of 90 seconds. The mixing and heating were maintained for ten minutes. The composition was then cooled to room temperature. The composition was a uniform, free-flowing granulation.
[0048] The effervescent composition of Example 2 was then formed into tablets on a hand press. The tablets had a mass ranging from 5.05 g to 5.24 g, a thickness of from 0.322 inch to 0.330 inch and a hardness of from 5.0 Kp to 5.5 Kp. The tablets, when placed in 200 mL of room temperature water, were observed to form a cloudy composition having a yellow residue after 15 minutes.
[0049] Other embodiments are within the claims.
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Disclosed is an effervescent composition and a method of making an effervescent composition that includes a viscous component and is a free flowing granulation.
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CROSS-REFERENCE TO RELATED U.S. APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention concerns a pentagonal screwdriver for screwing screws with pentagon-shaped heads or screws with five socket flats, in particular for screws usable in orthopedic surgery, such as hollow spindle-guided screws. It also aims at a system of screw works usable in particular in orthopedic surgery, featuring such a screwdriver and screws with pentagonal recesses.
[0007] 2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
[0008] Screws with polygonal recesses are well known and widely used as elements for fastening or assemblies, especially hex screws. Such screws are used in various industries and notably in orthopedic surgery to reunite bone fragments, in order to achieve the reduction of osseous fractures through osteosynthesis. The rotational drive of these screws is obtained by means of screwdrivers or keys presenting a working end with a section that is complementary to that of the recess of the screws.
[0009] The main disadvantage resulting from the use of hex screws and hex screwdrivers is that since the angles at the apex of a hexagon are 120°, the phenomenon of the screwdriver shifting in the recess occurs more easily. As a matter of fact, the more flats there are and the larger the angles, the more the geometrical shape tends towards the circle in which it is inscribed. There is hence little material to be deformed by the screwdriver to distort the recess of the screw head. The phenomenon of shifting is being amplified by the fact that in order to be able to insert the screwdriver into the recess of the screw, there necessarily has to be some play between the flats with respect to said screwdriver and said recess.
[0010] Furthermore, the stress is transferred through the six vertical edges of the screwdriver which wear down and deform the recess of the screw, the consequence of which may be that it will no longer be possible to remove the screw from the bone material into which it has been screwed.
[0011] The obvious solution to these disadvantages would be to create screws with a recess featuring a number of flats below 6. In fact, by reducing the value of the apex angles of the polygon (pentagon, square, triangle), it reduces or suppresses the shifting of the screwdriver shaped in complementary manner.
[0012] However, this solution is not applicable to the majority of screws used in orthopedic surgery, on account of the fact that the heads of these screws present, in their proximal portion, a very reduced diameter, generally in the order of 2 mm to 3 mm, in as much as these heads present, most of the time, a conical shape and that their diameter therefore diminishes progressively.
[0013] If one considers, for example, a system of screw works using screws with a square recess and a screwdriver shaped in complementary manner, the angles at the apex of a square being 90°, there is good transfer of stress. However, for a section equivalent to that of a hexagon, the square is inscribed in a circle of a larger diameter, and this all the more so, when its section is reduced by the value of the section of the guiding spindle. Thus, to be able to use a screw with a square recess, it requires a screw with a much bigger diameter than that of screws with a hexagonal recess. Now, in orthopedic surgery the heads of screws measure, as previously stated, from 2 to 3 mm. They can therefore have only very small square recesses where the distance between opposite flats would be close to the bore diameter receiving the guiding spindle, and in this case, taking into account the resulting very weak section, the screwdriver and/or the head of screw would not withstand the effect of the turning force.
[0014] Triangular recesses which would transfer the stress even better because of their 60° angles, would present the same disadvantage as the square recesses, in any application to orthopedic screws.
[0015] A good compromise, permitting to have the smallest angles possible, in order to transfer the stress torque, and the largest possible section of recess and end of the screwdriver, so that the latter will not break under the torsion effect and the recess of the screw head will not be deformed, would therefore be the utilization of screws with a pentagonal recess and of a pentagonal screwdriver.
[0016] Nuts with pentagonal recess and pentagonal drive wrenches have already been proposed.
[0017] For example, document JP-10.146.772 describes an Allen wrench with a cross section of pentagonal shape and a fastening screw with pentagonal recess which permit reducing the abrasion of the distal end of the wrench which is inserted into the recess of the nut.
[0018] Document GB-2.109.079 describes attaching nuts presenting a tail with a threaded axial bore and a conical head with a hexagonal or pentagonal hole, essentially used to ensure the fastening of U-bolts for metallic children's play structures providing secure fastening while avoiding sharp edges and which can be used with standard wrenches.
[0019] However, the use, by itself, of screw work systems featuring pentagonal wrenches or screwdrivers and screws with pentagonal recess, does not present a very significant progress relative to systems using screwdrivers and screws with hexagonal recess, as one does not know such systems being actually applied in industry and that they are not applied in the domain of orthopedic surgery.
[0020] Furthermore, in such screw work systems the generating line which transfers the stress is constituted by the five vertical edges. There still exists a shifting effect although it is less pronounced than for hexagonal screwdrivers because there is more material to deform.
[0021] One aim of the present invention is to remedy the aforementioned disadvantages by offering a reliable and precise solution to permit a more effective and more secure placement of screws, in particular in orthopedic surgery.
BRIEF SUMMARY OF THE INVENTION
[0022] According to the invention, this aim has been achieved because of a pentagonal screwdriver with at least one flat being inclined in the direction of the axis of said screwdriver.
[0023] The screwdriver according to the invention provides several interesting advantages. It makes it possible in particular:
to compensate for play which exists between a screwdriver and the recess of a screw head; to avoid shifting by firmly applying the flats of the screwdriver which are opposite the inclined flat against the corresponding faces of the recess of the screw head; to transfer the stress through the intermediary of an edge, of two flats and one angle; and to have a gripping effect which permits holding the screw of the screwdriver.
[0028] According to an advantageous embodiment, the inclined flat of the screwdriver presents an incline between 2° and 3°.
[0029] According to a preferred embodiment, the inclined flat presents an inclination of 2° for use with screws featuring a head diameter of 2 mm or less than 2 mm, and an inclination of 3° for use with screws featuring a head diameter above 2 mm.
[0030] According to another characteristic arrangement, the screwdriver according to the invention presents an axial bore permitting the passage of a piercing spindle used for performing certain operations in orthopedic surgery.
[0031] According to a preferred embodiment, the screwdriver is made of any so-called surgical material presenting the necessary hardness.
[0032] According to an advantageous embodiment, the screwdriver according to the invention is made of stainless steel having undergone a heat treatment with the aim of increasing its hardness.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The aforementioned aims, characteristics and advantages, and others will become clearer from the description which follows and the attached drawings in which:
[0034] FIG. 1 is a perspective view of an embodiment of the pentagonal screwdriver according to the invention.
[0035] FIG. 2 is a front view and at a larger scale of the distal part of the pentagonal screwdriver, illustrating the inclined flat.
[0036] FIG. 3 is a view of the underside and at a larger scale of the distal part of the screwdriver.
[0037] FIG. 4 is a detailed section view and at a larger scale, of a pentagonal screwdriver as it is being inserted into a screw head with a pentagonal recess.
[0038] FIG. 5 is an analog view to FIG. 4 and shows the screwdriver completely inserted into the screw head with pentagonal recess.
[0039] FIG. 6 is a view from above in a section along the line 6 - 6 of FIG. 5 showing the edges or the surfaces which transfer the screwing torque.
[0040] Reference is made to the drawings to describe an interesting, although by no means limiting example, of the pentagonal screwdriver according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] The following description and claims are limited to a screwdriver but the device according to the invention can also be adapted to a wrench or to any other appropriate fastening system.
[0042] The pentagonal screwdriver 1 according to the invention features a distal drive end with five flats of which at least one flat 2 is inclined in relation to the longitudinal axis A of the screwdriver and in the direction of that axis.
[0043] According to an advantageous embodiment, said inclined face 2 presents an inclination between 2° and 3°.
[0044] Preferably, said inclination amounts to 2° for use with screws featuring a diameter of 2 mm or less than 2 mm, and 3° for use with screws featuring a head with a diameter above 2 mm.
[0045] According the example shown the pentagonal screwdriver 1 presents an axial bore permitting the passage of a guiding spindle.
[0046] According to an advantageous embodiment the screwdriver 1 is made of any so-called surgical material presenting the necessary hardness, for example of stainless steel.
[0047] According to the example shown in FIG. 4 , the inclined flat or face 2 permits as a first step, to provide some play which makes it possible to insert the screwdriver 1 into the pentagonal recess or at five socket faces E of the head of the screw V.
[0048] As the screwdriver 1 is inserted into the recess E of the screw head, the play diminishes and disappears altogether, thus permitting the screwdriver to perfectly match up with the shape of the recess E of the screw V ( FIG. 5 ).
[0049] Furthermore, when the screwdriver is completely inserted into the recess E of the head of screw V, the inclined face 2 makes it possible to place the two faces or flats 3 and 4 , opposite the inclined flat 2 , closely against the corresponding socket faces of the recess of the screw, as indicated by the arrow on FIGS. 5 and 6 .
[0050] The screwdriver 1 then finds itself immobilized in the head of the screw V and the inclined flat creates a gripping effect.
[0051] Thus the stress applied to the screwdriver 1 to screw or unscrew an orthopedic screw is transferred to said screw through the intermediary of the edge 2 a of the inclined flat 2 by the faces 3 and 4 opposite to said inclined flat 2 and by the angle comprised between said faces 3 and 4 .
[0052] The pentagon of the screwdriver 1 being convex and regular, its interior angles amount to 108° which permits a better transfer of the stress than that obtained by the means of screw work systems using socket hex screws and screwdrivers with angles of 120°.
[0053] Utilization of this geometric shape is also remarkable in that the surface of the circle in which the pentagon is inscribed and which is not occupied by the pentagon is larger than for a hexagon.
[0054] In this way, any manifestation of the shifting phenomenon leading to a deformation of the material of the head of the orthopedic screw V is eliminated.
[0055] The invention also concerns a screw work system including screws with pentagonal recess and a screwdriver featuring one or several of the characteristic arrangements previously described and disclosed in the claims.
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A pentagonal screwdriver, for screwing screws with pentagonal recesses, in particular orthopaedic screws with one face thereof tilted relative to and in the direction of the longitudinal axis of said screwdriver, the other four faces of the screwdriver being straight and parallel to said longitudinal axis.
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BACKGROUND OF THE INVENTION
This invention relates to a finish composition for treating a polyamide yarn which resists bacteria growth and causes the treated yarn to resist yellowing under steam heat treatment. More particularly, this invention relates to a finish composition for polyamide yarn to be processed into carpet yarn.
The prior art is replete with finishes for synthetic filament yarn. However, the critical combination of and proportion of ingredients required to achieve the specific, beneficial results of this invention are not taught in the prior art.
The problem specifically addressed by the present invention is the spot yellowing of nylon carpet yarn, either bulked continuous filament or staple carpet yarn, during autoclaving of the yarn. By autoclaving is meant placing yarn in a pressure vessel and subjecting it to steam treatment of various times, temperatures, and pressures.
SUMMARY OF THE INVENTION
The present invention provides a finish composition and an improved process for treating polyamide yarn, in which the finish composition resists bacteria growth and causes the treated yarn to resist yellowing under steam heat treatment.
The improvement in the process for the production of polyamide yarn, comprises treating the yarn during spinning with from about 0.5 to 1.2 percent by weight of the yarn of a finish composition. The finish composition consists essentially of from about 99.5 to 99.995 percent by weight of an oil in water emulsion and from about 0.005 to 0.500 percent by weight of 2[(hydroxymethyl)amino]ethanol, about 10 to 20 percent by weight of the emulsion being an oil portion.
This finish composition, which resists bacteria growth and causes polyamide yarn treated therewith to resist yellowing under steam heat treatment, consists essentially of:
a. from about 99.5 to 99.995 percent of an oil in water emulsion, about 10 to 20 percent by weight of the emulsion being an oil portion, the oil portion consisting essentially of from about 55 to 65 percent by weight of coconut oil, about 20 to 35 percent by weight of polyoxyethylene hydrogenated castor oil, and about 7 to 15 percent by weight of potassium salt of polyoxyethylene tridecyl phosphate; and
b. from about 0.005 to 0.500 percent by weight of 2[(hydroxymethyl)amino]ethanol.
An alternate but equally effective finish composition, which resists bacteria growth and which causes polyamide yarn treated therewith to resist yellowing under steam heat treatment, consists essentially of:
a. from about 99.5 to 99.995 percent by weight of an oil in water emulsion, about 10 to 20 percent by weight of the emulsion being an oil portion, the oil portion consisting essentially of about 55 percent by weight of mineral oil, from about 11 to 12 percent by weight of fatty acid soap, about 15 percent by weight of sulfonated ester ethoxylate, about 12 percent by weight of polyethylene glycol ether, and from about 0 to 1 percent by weight of triethanolamine; and
b. from about 0.005 to 0.500 percent by weight of 2[(hydroxymethyl)amino]ethanol.
The invention further comprises a method of making synthetic yarn finish compositions resistant to bacteria growth, whereby yarn treated therewith resists yellowing under steam heat treatment. The method comprises adding from about 0.005 to 0.500 percent by weight of the finish composition of 2[(hydroxymethyl)amino]ethanol to an oil in water finish emulsion.
More preferably, the oil in water emulsion and 2[(hydroxymethyl)amino]ethanol form, respectively, about 99.80 to 99.95 and about 0.05 to 0.20 percent by weight of the recited finish compositions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As mentioned previously, it was found that during autoclaving at temperatures of about 138° C. (280° F.) polyamide yarn to be processed into carpet yarn yellowed. The yellowing occurred only in spots and always in the same pattern in the autoclave.
A test was run to determine the cause of the yellowing. Three different nylon polymers, amine terminated nylon polymer, an unterminated nylon polymer, and an acid terminated nylon polymer, were melt spun with three different finishes and dipped into a solution of biocide to obtain from 0.1 to 5 percent biocide on yarn. The spin finishes were liquid compositions consisting essentially of an oil in water emulsion, about 10 to 20 percent by weight being an oil portion. The oil portion of the three finishes had the formulations set forth in Table I.
TABLE I______________________________________FINISH FORMULATIONS WeightFinish Composition Percent______________________________________A Mineral oil 55 Fatty acid soap 11 Sulfonated ester ethoxylate 15 Polyethylene glycol ester 12 Polyethylene glycol ether 6 Triethanolamine 1B Mineral oil 55 Fatty acid soap 12 Sulfonated ester ethoxylate 15 Polyethylene glycol ester 12 Polyethylene glycol ether 6C Coconut oil 59 Polyoxyethylene (25).sup.a castor oil 15.5 Decaglycerol tetraoleate 7.5 Glycerol monooleate 3.0 Polyoxyethylene (20).sup.a sorbitan monooleate 5.0 Sulfonated petroleum product 10.0______________________________________ .sup.a = Moles of ethylene oxide per mole of base material
The biocide utilized was 6-acetoxy-2,4-dimethyl-m-dioxane. The samples obtained were autoclaved at about 138° C. (280° F.). Results of the tests are presented in Table II. The results show that yellowing of the nylon is due to the biocide, is proportional to polymer amine end groups, and independent of spin finish. All of the nylon polymers tested showed yellowing at biocide concentrations of 1 percent, and the amine terminated nylon polymer showed yellowing at 0.1 percent biocide concentration.
Based on these results, several biocides were screened for yellowing on amine terminated nylon polymer yarn bearing spin finish A described in Table I. Results are presented in Table III. Samples F through M showed no significant yellowing at a biocide concentration of 0.5 percent on an amine terminated nylon polymer yarn. The biocide used in these samples (F through M) were then tested (two trials) for their ability to control bacteria growth in a finish A (Table I) emulsion. The results of this test are presented in Table IV. In table IV, the concentration (%) of biocide represents the percent by weight of biocide in a finish composition consisting essentially of finish A and the biocide. The initial concentration was 0.01 percent by weight of biocide. If after 10 days bacteria were not present in the emulsion, then smaller concentrations of biocide were tested. If after 10 days bacteria were present in the emulsion, higher concentrations of biocide were tested. The results show that four biocides were effective both with respect to bacteria growth and yellowing formaldehyde; 2[(hydroxymethyl)amino]-2-methylpropanol; 3,5-dimethyltetrahydro-1,3,5,2H-thiadizone-2 -thione; and 2[(hydroxymethyl)amino]ethanol.
TABLE II______________________________________YELLOWING TEST Biocide Concentration Applied Spin 0.1% 0.5% 1% 3% 5%Polymer Type Finish Yellowing Rating*______________________________________Amine terminated nylon A 1 2 4 5 5polymerAmine terminated nylon B 1 2 3 4 4polymerAmine terminated nylon C 0 1 3 4 5polymerUnterminated nylon A 0 1 1 3 4polymerUnterminated nylon B 1 1 3 4 4polymerUnterminated nylon C 0 0 1 3 3polymerAcid terminated nylon A 0 0 1 3 3polymerAcid terminated nylon B 0 1 1 2 3polymerAcid terminated nylon C 0 0 1 2 3polymer______________________________________ *Yellowing Rating 0 No yellowing 1 Very slight yellowing 2 Slight yellowing 3 Yellowing 4 Heavy yellowing 5 Extremely heavy yellowing
TABLE III______________________________________ CONCENTRA- TION OF BIO- CIDE APPLIEDSam- 0.1% 0.5% 1.0%ple Biocide Yellowing Rating*______________________________________A 6-acetoxy-2,4-dimethyl-m-dioxane 1 2 4B 1,2-benzisothiazolin-3-one 0 3 4C 2-bromo-2-nitropropane-1,3-diol 4 5 5D dichlorophene phenol 1 5 --E 1,5-pentanediol 1 5 --F p-hydroxybenzyl acetate 0 0 0G p-hydroxybenzyl propionate 0 0 0H formaldehyde 0 0 0I sodium orthophenylphenol 0 0 3J 3,5-dimethyltetrahydro-1,3,5,2H- 0 0 2thiadiazine-2-thioneK 2-[(hydroxymethyl)amino]-2-methyl- 0 0 1propanolL 2[(hydroxymethyl)amino]ethanol 0 0 2M 1-(3-chloroalkyl)-3,5,7-triazo-1- 0 0 0azoniaadamantane______________________________________ *Yellowing Rating 0 No yellowing 1 Very slight yellowing 2 Slight yellowing 3 Yellowing 4 Heavy Yellowing 5 Extremely heavy yellowing
TABLE IV______________________________________BACTERIA CONTROL TESTS IN FINISH A Concen- Presence tration of BacteriaBiocide (%) After 10 Days______________________________________control (no biocide) -- yesp-hydroxybenzyl acetate .01 yesp-hydroxybenzyl acetate .02 yesp-hydroxybenzyl acetate .03 yesp-hydroxybenzyl propionate .01 yesp-hydroxybenzyl propionate .02 yesp-hydroxybenzyl propionate .03 noformaldehyde.sup.1 .01 noformaldehyde.sup.1 .005 noformaldehyde.sup.1 .0025 yessodium orthophenylphenol .01 yessodium orthophenylphenol .02 yessodium orthophenylphenol .03 no3,5-dimethyltetrahydro-1, .005 yes3,5,2H-thiadiazine-2-thione3,5-dimethyltetrahydro-1, .01 no3,5,2H-thiadiazine-2-thione3,5-dimethyltetrahydro-1, .02 no3,5,2H-thiadiazine-2-thione3,5-dimethyltetrahydro-1, .03 no3,5,2H-thiadiazine-2-thione2-[(hydroxymethyl)amino]- .005 no2-methylpropanol2-[(hydroxymethyl)amino]- .01 no2-methylpropanol2-[(hydroxymethyl)amino]- .02 no2-methylpropanol2-[(hydroxymethyl)amino]- .03 no2-methylpropanol2[(hydroxymethyl)amino]ethanol .005 no2[(hydroxymethyl)amino]ethanol .01 no2[(hydroxymethyl)amino]ethanol .02 no2[(hydroxymethyl)amino]ethanol .03 no1-(3-chloroalkyl)-3,5, .01 yes7-triazo-1-azoniaadamantane1-(3-chloroalkyl)-3,5, .02 yes7-triazo-1-azoniaadamantane1-(3-chloroalkyl)-3,5, .03 yes7-triazo-1-azoniaadamantane______________________________________ 1 Concentration represents active formaldehyde.
The first two of these biocides were deemed unacceptable due to a threat of skin irritation or other toxicological properties. The third biocide is not deemed to constitute a part of the present invention due to its disclosed use as an effective fungicide contained in a textile fiber finish (Defensive Publication No. T875,001 of Burress et al).
The biocide constituting a part of the present invention, 2[(hydroxy)methyl)amino]ethanol, is an alkanolamine. To demonstrate the criticality of this particular alkanolamine, further tests were run to evaluate selected alkanolamines with respect to biocidal potential and yellowing. Results are presented in, respectively, Tables V and VI. Finish X of Table V is more fully described in co-pending patent application U.S. Ser. No. 859,762, filed Dec. 12, 1977, hereby incorporated by reference.
The invention will now be further described in the following specific examples which are to be regarded solely as illustrative and not as restricting the scope of the invention. In the following examples, parts and percentages employed are by weight unless otherwise indicated.
EXAMPLE I
A reactor equipped with a heater and stirrer is charged with a mixture of 1,520 parts of epsiloncaprolactam and 80 parts of aminocaproic acid. The mixture is then flushed with nitrogen and stirred and heated to 255° C. over a one-hour period at atmospheric pressure to produce a polymerization reaction. The heating and stirring is continued at atmospheric pressure under a nitrogen sweep for an addional four hours in order to complete the polymerization.
TABLE V______________________________________BACTERIA CONTROLS TESTS IN FINISHES A.sup.1 and X.sup.2 Concentration PresenceBiocide in Finish (%) of Bacteria______________________________________Control -- yesTriethanolamine .01 yesTriethanolamine .05 yesTriethanolamine .1 yesTriethanolamine .2 yesDiethanolamine .01 yesDiethanolamine .05 yesDiethanolamine .1 yesDiethanolamine .2 no2[(hydroxymethyl)amino]ethanol .01 no______________________________________ .sup.1 = Same as Finish A of Table I; about twenty (20) percent by weight of emulsion was oil portion. .sup.2 = Finish X was an oil in water emulsion, about sixteen (16) percen by weight of emulsion was oil portion. The oil portion consisted essentially of the following ingredients:
Weight PercentRefined coconut glyceride 60Polyoxyethylene (16).sup.a hydrogenated castor oil 30Polyoxyethylene (5).sup.a tridecyl phosphate, 10potassium salt______________________________________ .sup.a = moles of ethylene oxide per mole of base material
TABLE VI______________________________________YELLOWING TEST Biocide Concen- tration Applied 0.1% 0.5% 1.0% Yellowing Rating on Amine TerminatedBiocide Finish Nylon Polymer Yarn*______________________________________Triethanolamine X (Table V) 3 4 5Diethanolamine X (Table V) 2 3 52[(hydroxymethyl)amino]- X (Table V) 0 0 2ethanol______________________________________ *Yellowing Rating 0 No yellowing 1 Very slight yellowing 2 Slight yellowing 3 Yellowing 4 Heavy yellowing 5 Extremely heavy yellowing
Nitrogen is then admitted to the reactor and a small pressure is maintained while the polycaproamide polymer is extruded from the reactor in the form of a polymer ribbon. The polymer ribbon is subsequently cooled, pelletized, washed and dried. The polymer is a white solid having a relative viscosity of about 50 to 60 as determined at a concentration of 11 grams of polymer in 100 ml. of 90 percent formic acid at 25° C. (ASTM D-789-62T).
The polymer pellets are melted at about 285° C. and melt extruded under pressure of about 1,500 psig. through a 70-orifice spinnerette to produce an undrawn yarn having about 3,600 denier. The finish composition which is applied to the yarn consists essentially of:
a. about 99.9 percent by weight of an oil in water emulsion, about 16 percent by weight of the emulsion being an oil portion consisting essentially of about 60 percent by weight of refined coconut glyceride, about 30 percent by weight of polyoxyethylene (16) a hydrogenated castor oil, and about 10 percent by weight of polyoxyethylene (5) a tridecyl phosphate, potassium salt, wherein the superscript a refers to moles of ethylene oxide per mole of base material; and
b. about 0.1 percent by weight of 2[(hydroxymethyl)amino]ethanol, manufactured under the trade name of Troysan 174 by the Troy Chemical Company, One Avenue L, Newark, N.J. 07105. This finish composition, which on testing does not exhibit the presence of bacteria, is applied to the yarn as a spin finish in amount to provide about 0.9 percent by weight of oil based on the weight of yarn. The yarn is then drawn at about 3.2 times the extruded length and textured with a steam jet to produce a feeder yarn suitable for production of plied, bulked continuous filament carpet yarn. This yarn is then autoclaved at a temperature of about 138° C. The autoclaved yarn exhibits no yellowing.
EXAMPLE 2
The procedure of Example 1 is followed except that the polymer is spun and combined into a tow of yarn which is stretched, steam textured, chopped into 7 inch lengths and baled. From these bales, the fibers are carded to form a roving suitable for the production of staple carpet yarn. This yarn is then autoclaved at a temperature of about 138° C. The autoclaved yarn exhibits no yellowing.
EXAMPLE 3
The procedure of Example 1 is followed except that the finish composition which is applied to the yarn consists essentially of:
a. about 99.9 percent by weight of an oil in water emulsion, about 20 percent by weight of the emulsion being an oil portion consisting essentially of about 55 percent by weight of mineral oil, about 12 percent by weight of fatty acid soap, about 15 percent by weight of sulfonated ester ethoxylate, about 12 percent by weight of polyethylene glycol ester, and about 6 percent by weight of polyethylene glycol ether; and
b. about 0.1 percent by weight of 2[(hydroxymethyl)amino]ethanol, manufactured under the trade name of Troysan 174 by the Troy Chemical Company, One Avenue L, Newark N.J. 07105. The finish composition of this example also on testing does not exhibit the presence of bacteria, and the autoclaved yarn exhibits no yellowing.
EXAMPLE 4
The procedure of Example 2 is followed utilizing the finish composition of Example 3. The autoclaved yarn exhibits no yellowing.
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A finish composition for polyamide yarn which comprises an oil in water emulsion and an effective amount of 2[(hydroxymethyl)amino]ethanol biocide resists bacteria growth and causes the treated yarn to resist yellowing under steam heat treatment. The oil in water emulsion and biocide most preferably form, respectively, 99.9 percent and 0.1 percent by weight of the finish composition. The preferred oil in water emulsion is about 10 to 20 percent by weight of the oil portion, the oil portion consisting essentially of from about 55 to 65 percent by weight of coconut oil, about 20 to 35 percent by weight of polyoxyethylene hydrogenated castor oil, and about 7 to 15 percent by weight of potassium salt of polyoxyethylene tridecyl phosphate. The finish composition is especially useful for application to polyamide yarn to be processed into either staple carpet yarn or bulked continuous filament carpet yarn.
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FIELD OF THE INVENTION
The subject of the present invention is a centre which can be made of injection-moulded plastic, is substantially tubular in shape and is designed to receive yarn wound in turns; centres of this kind are intended to undergo various processing operations and in particular dyeing treatments using liquid dye which must penetrate through the turns of the yarn in order to dye it in the most uniform way possible; the spools of yarn wound on the centres are consequently inserted in suitable dyeing equipment in order to carry out the abovementioned operation. In the case of certain yarns especially, the yarn shortens when wetted and heated, which can give rise to high tightening forces being exerted on the centre; for these reasons, it is advantageous for the centre to be able to undergo a reduction in its diameter i.e. in its transverse section, in order to reduce the forces exerted by the yarn and especially to make these forces substantially uniform even deep within the spool, so as to ensure that the mass of yarn wound in turns is dyed in a substantially uniform manner. Centres which allow this reduction in transverse section, i.e. in practical terms a reduction in diameter, are already known but these known centres have certain drawbacks and in particular considerable reduction in the area through which the dyeing liquid can pass through the permeable walls of the centre once it has undergone a reduction in diameter. A further drawback of known centres of this type is that the reduction in diameter often cannot be controlled and can give rise to an excessive undesirable contraction which can lead to additional problems.
A recent type of centre (App. FI92U 102 of Aug. 28, 1992, laid open for public inspection on Feb. 28, 1994 and EP Appl no. 93830308.8 of Jul. 20, 1993, Publish Mar. 16, 1994) is capable of a reduction in the diameter, i.e. the transverse section of the centre, while maintaining a large cross section of the holes that pass through the tubular cylindrical wall of the centre even when its diameter is reduced; it has, on its cylindrical wall, adjacent longitudinal rows of slots which are elongated lengthwise, the slots of one row being staggered--generally by half a pitch--with respect to those of the contiguous rows; in this way the longitudinal edges of each slot can be brought closer together in the intermediate zone, allowing a substantially uniform reduction in the transverse section of the centre when the cylindrical wall of the dentre is subjected to centripetal pressure caused by the tensions induced in the turns of the wound yarn. This centre only allows reductions in diameter, and these reductions in diameter are caused by the tensions created in the turns when wetted by the hot dye.
Centres for the uses indicated above and capable of undergoing axial shortening when pressed during the insertion of a stack of packages into a dyeing or other type of apparatus, are also known.
SUMMARY AND OBJECTS OF THE INVENTION
The present invention allow the diameter to be reduced and, at the same time, allows the axial dimensions to be reduced, with no particular stresses in the yarn, which can be damaged by tension.
The centre according to the invention made from injection-moulded plastic for forming spools of yarn wound about it in turns for processes such as dyeing in particular and for subsequent distribution of the yarn--has, on its cylindrical wall, rows of elongate slots oriented such that the longitudinal edges of at least some of the slots can approach each other in the middle, thereby enabling a reduction in the dimensions of the centre when pressure is applied to the centre's cylindrical wall. The present centre is also characterized in that in the rows of elongate slots, the slots are arranged alternately at at least two angles, in such a way that when the centre is compressed axially and/or radially, the longitudinal edges of at least some of the slots approach each other in the middle, bringing about both a reduction in the axial dimension and a reduction in the transverse section of the centre.
In practice, the rows of elongate slots may be arranged in intersecting helical alignments, on each of which alignments slots are arranged alternately with their greatest dimension along said helical alignment and transversely to it, while at each intersection is a slot belonging to both alignments. The helical alignments may intersect at approximately 90° with respect to each other.
In practice, inserting a stack of reels into a dyeing apparatus, and pushing axially on the centres as they lie on top of each other, simultaneously brings about a linear shortening of the height of the stack of centres and a reduction in their diameter, with no tensions in the yarn.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a front external view of the center according to the invention, before undergoing contraction in length and transverse section as a result of axial compression;
FIG. 2 is a front external view of the center FIG. 1 after undergoing contraction and length and transverse section as a result of axial compression;
FIG. 3 is a detailed view showing the surface of the center before deformation as a result of axial compression;
FIG. 4 is a detailed view of the surface of the center after the deformation as a result of axial compression; and
FIG. 5 shows a local section taken along the line V--V indicated in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As illustrated in the drawing, the numeral 1 in FIG. 1 indicates the complete centre, which is cylindrical in shape with a stepped end 1A and an end 1B shaped for centring on the rim 1A of the next centre down, in an arrangement which is known per se; one of the ends may also be shaped to form a reserve of yarn. The wall characteristically has two series of helical rows of elongate slots 3. The angle of the helical rows of one series is the opposite of that of the helical rows of the other series, so that the rows of the two series intersect; the angles of the helixes are preferably equal and opposite and may each be 45° giving a 90° intersection, in the moulded and undeformed centre. Each slot is elongate and therefore has two longitudinal edges, which originally are a certain distance apart and may comprise an intermediate portion that is straight. Each helical row of slots alternately has one slot lying longitudinally and one slot lying transversely relative to the helical line; a slot 3 lies at the intersection between two helical lines and is longitudinal for one row and transverse for the other row; each transverse slot is preferably positioned symmetrically with respect to the helical line of the row of slots 3 to which it belongs. In an intermediate position along each of the longitudinal sides of each of the slots 3 there may be projections 5 (see FIGS. 3 and 5)--shown in the drawing as being symmetrically opposite each other in pairs--which in the normal conditions of a new centre (FIGS. 1 and 3) are separated from each other by a distance D. In practice the projections 5 of the slots 3 of one helical row of slots correspond to the helical axis of the helical row of slots which it intersects. The projections 5 are set back from the outer surface of the centre, marked 1X in FIG. 5; in practice the projections 5 may be flush with the inner surface 1Y of the cylindrical wall of the centre.
The centre is designed to have wound on it a spool of yarn intended for handling operations, and especially dyeing. The liquid dye is generally introduced into the interior of a stack of centres, i.e. a stack of spools, and has to pass through the mass of turns of yarn in order to dye it.
In dyeing apparatuses, many centres 1 with their spools of yarn are placed on a centre guide column through which the liquid dye is passed; the apparatus is often provided with means which axially clamp together the centres mounted on the column. These means are used to bring about the deformation of all the centres installed on one column; with the present centre, this deformation takes the form of a reduction in the axial dimension of the centre and a simultaneous reduction in the transverse section, i.e. the diametrical dimension, of the centre, with a certain slackening of yarn wound around the centres, which yarn can thus shorten with no real tension during the dyeing or other treatments. The axial compression deforms the centre--as can be seen by comparing FIGS. 1 and 2 and also by comparing FIGS. 3 and 4--both axially and radially. This brings together and axially compresses the spools of the stack of centres; it also allows the wound yarn to shorten. The deformations produced by the axial compression of the centre (in the direction of arrows f in FIG. 4) causes the longitudinal edges of the elongate slots to approach each other with the result that the projections 5 tend to come together and reduce the dimension D between the confronting extremities of these projections 5. Moreover, at the limit, the extremities of the projections 5 will touch each other and thus eliminate the distance D, but the reduction in the free cross section of the slots 3 is halted at this limit, which represents the maximum reduction of the cross section. The alternate angles and the staggering of the slots 3 of the helical rows of the two series allow the transverse section and axial dimension of the centre to reduce, with a slight deformation of the cylindrical wall. Even when reduced, the elongate slots 3 maintain what is comparatively a very large through cross section, which enables the liquid dye to flow from the interior through the mass of turns of the spool and out (or in the reverse direction).
The projections 5 are set back from the outer surface 1X of the centre, so avoiding any risk of the yarn being pinched by the projections 5 as they close on each other; in practice, the projections 5 are narrower than the thickness of the wall of the centre and are generally flush with the inner surface 1Y of the cylindrical wall of the centre.
The step, such as 1A, or other equivalent arrangement facilitates the centring and stacking of successive centres, avoiding the need for an intermediate separating plate.
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A center with elongated slots (3) for reducing axial and transverse sections of the center. The elongate slots (3) are arranged in two series of intersecting helical alignments; on each of these alignments slots are arranged alternately with their greatest dimension along said helical alignment and transversely to it; at each intersection is a slot belonging to both alignments. When an axial compressive force is applied the slots shrink, thereby simultaneously reducing the axial and diametrical dimensions.
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FIELD OF THE INVENTION
The present invention relates to the art of vehicular non-contact anti-pinch systems for preventing a closure panel such as a window or sliding door from pinching an object such as a person's hand as the closure panel moves into its closed position.
BACKGROUND OF THE INVENTION
Proximity sensors are widely used in the automotive industry to automate the control of power accessories. For instance, proximity sensors are often used in power window controllers to detect the presence of obstructions in the window frame when a window panel is being directed to the closed position. Such sensors can also be used to detect the presence of obstructions in other types of automotive closures such as sunroofs, side doors, sliding doors, lift gates, and deck lids.
A variety of capacitor-based proximity sensors are known in the art. For example, U.S. Pat. No. 6,377,009 discloses a system for preventing the pinching or trapping of a foreign object by a closing panel (such as a window) through the use of a sensing electrode or plate. This electrode is a metal strip or wire which is embedded in a plastic or rubber molding strip placed behind a piece of fascia or other trim part. The metal strip or wire and the chassis of the vehicle collectively form the two plates of a sensing capacitor. A foreign object placed between these two electrodes changes the dielectric constant and thus varies the amount of charge stored by the sensing capacitor over a given period of time. The charge stored by the sensor capacitor is transferred to a reference capacitor in order to detect the presence of a foreign object. Similar capacitive sensing applications are known from DE 4036465A, DE 4416803A, DE 3513051A1, DE 4004353A.
There are two major problems that have to be overcome for capacitive anti-pinch systems to work well in practice.
The first problem relates to the large background capacitance presented by the relatively enormous area of the sheet metal and plastic surrounding the closure aperture. For instance, in a power sliding door application, there is a large gap in between the sliding door and the vehicle frame. The presence of a small element such as a child's finger may not make an appreciable difference to the overall capacitance, and thus may be rejected as noise. Alternatively, if a relatively high sensitivity is employed to detect such a small change, too many false positives may occur (it being understood that no system is perfect and that there many some acceptable degree of false positives).
The second problem relates to the variable capacitance presented by changing humidity or water levels. The existence of high humidity or water will increase the dielectric constant of the system and thus will either mask the presence of a small object such as a child's finger or cause too many false positives.
In order to deal with such issues, it is known to utilize capacitive shielding and a differential capacitance sensing system which reduces the effect of parasitic capacitance arising from the sheet metal. It is also known to map the background capacitance as the closure panels opens and use that map as a reference as the closure panel closes to detect a differential. And it is known to vary the sensitivity of the system as the closure panel nears its final closing position. See, for instance, Applicant's PCT Publication Nos. WO 2002/101929, WO 2002/012699, WO 2003/038220, and WO 2005/059285.
However, the presence of water can still cause too many false positives, particularly when the sensor itself is wet. And since a human being's dielectric constant is similar to the dielectric constant of water, there could be a situation when the presence of water on the sensor causes too many false positives.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, a method is provided for preventing a closure panel from pinching an obstruction extending through an aperture of a motor vehicle having a motor to drive the closure panel between an open position and a closed position. The method includes: measuring a capacitance of a field extending through the aperture using a capacitive sensor as the motor drives the closure panel between the open and closed positions; identifying a position of the motor using a position sensor as the motor drives the closure panel between the open and closed positions; correlating the measured capacitance to the position identified to create closing data; comparing the closing data to a reference map to create a compare value; and detecting an object in a path of the closure panel as the closure panel moves toward the closed position when the compare value exceeds a threshold value dependent on the relative wetness of the sensor.
The threshold value is preferably adjusted for each closure of the panel by comparing the capacitance of the sensor at predetermined closure panel positions against a calibration wetness profile to determine the relative wetness of the capacitive sensor and determine a threshold adjustment value based on the relative wetness of the capacitive sensor.
The reference map is preferably generated each time the closure panel moves from the closed position to the open position by: measuring a capacitance of the field extending through the aperture using the capacitive sensor as the motor drives the closure panel, identifying a position of the motor using the position sensor as the motor drives the closure panel, and correlating the measured capacitance to the position identified.
Preferably, the method also includes measuring a time period that the compare value exceeds the threshold value to distinguish the detection of the object from noise.
The capacitance may be measured indirectly by cyclically charging the capacitance sensor and transferring charge therefrom to a reference capacitor, and either measuring the voltage of the reference capacitor after a predetermined number of charging cycles or measuring the number of cycles required to charge the reference capacitor to a predetermined voltage.
The capacitive sensor preferably includes a non-conductive casing, a first at least partially conductive body embedded in the casing, a second at least partially conductive body embedded in the casing, an air gap between the first and second at least partially conductive bodies, a first conductive strip electrode embedded in the first dielectric body, and a second conductive strip electrode embedded in the second dielectric body, wherein the casing, the at least partially conductive bodies and the strip electrodes are sufficiently flexible to allow the first and second at least partially conductive bodies to contact one another upon the application of a predetermined pinch force.
Utilizing such a capacitive sensor, the method preferably includes further detecting an object in the path of the closure panel as it moves toward the closed position when the electrical resistance between the first and second electrodes falls below a predetermined resistance.
The method may also include further detecting an object in the path of the closure panel as it moves toward the closed position by monitoring the position sensor to for lack of change therein or by monitoring the current drawn by the motor.
Once an object is detected, the closure panel is prevented from continuing to move toward the closed position and is preferably reversed.
A controller and control circuitry is enabled to carry out the foregoing functions.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other aspects of the invention will be better understood from the following detailed description of preferred embodiments of the invention in conjunction with the drawings thereof, wherein:
FIG. 1 is a diagram of an automotive door having an obstruction sensor mounted thereto;
FIG. 2 is a cross-sectional view of a portion of an elongate obstruction sensor taken along line 2 - 2 in FIG. 1 ;
FIG. 3 is a system block diagram of an anti-pinch system;
FIG. 4 is a schematic graph illustrating a method of detecting an object based on capacitive sensing;
FIG. 5 is a graph of the capacitance of a sensor over varying wetness conditions; and
FIG. 6 is a graph of an adjustment factor based on the degree of sensor wetness.
DETAILED DESCRIPTION OF THE INVENTION
This application incorporates the following publications by reference in their entirety:
PCT Publication No. WO 2002/101929 PCT Publication No. WO 2002/012699 PCT Publication No. WO 2003/038220 PCT Publication No. WO 2005/059285
FIG. 1 illustrates a typical automotive door 12 that is comprised of sheet metal and includes an aperture 14 , structured as a window frame 40 , which may be closed by a window pane or glass panel 16 . The glass panel 16 is raised or lowered by a window regulator (not shown) which includes an electric motor as the motive driving source, as well known in the art per se. The motor is controlled in part by a non-contact obstruction sensor or anti-pinch assembly 10 , the particulars of which are described in greater detail below. The anti-pinch assembly 10 includes an elongate sensor 18 that prevents the glass panel 16 from pinching or crushing a foreign object such a finger (not shown) that may be extending through the aperture 14 when the panel nears its closed position. It will be appreciated by those skilled in the art that the anti-pinch assembly 10 can be applied to any motorized or automated closure panel structure that moves between an open position and a closed position. For example, a non-exhaustive list of closure panels includes window panes, sliding doors, lift gates, sunroofs and the like. For applications such as window panes or sun roofs, the elongate sensor 18 may be mounted on the frame of the vehicle, and for applications such as powered sliding doors the elongate sensor 18 may be mounted on the closure panel itself, .e.g., at the leading edge of the sliding door. For ease of description, the remainder of this disclosure will focus on the windowpane and window frame combination, it being understood that the apparatus and methods described herein can be applied to other types of vehicular closure systems.
Referring additionally to FIG. 2 , the elongate sensor 18 includes a non-conductive casing 20 mounted near or on the upper part of window frame 40 as seen in FIG. 1 . Two conductive strip electrodes 24 a and 24 b such as wires are preferably disposed in the casing 20 . Electrode 24 a is embedded in a first partially conductive body 26 a and electrode 24 b is embedded in a second partially conductive body 26 b . These partially conductive bodies 26 a , 26 b may be formed from a carbonized or electrically conductive rubber, and the surfaces 28 a , 28 b of these bodies preferably have a greater concentration of carbon or conductive material and thus able to carry a greater current than the inner part of the body. An air gap 22 separates the two partially conductive bodies 26 a , 26 b , and an adhesive tape 30 provides a means for fastening the casing 20 to the window frame 40 .
The casing 20 is preferably formed as an extruded, oblong, elastomeric trim piece with co-extruded upper and lower partially conductive bodies 26 a , 26 b , and the electrodes 24 a and 24 b are molded directly into the bodies 26 a , 26 b . The trim piece can be part of the window water sealing system, i.e., form part of a seal, or can form part of the decorative fascia of the vehicle.
The air gap 22 electrically insulates the two electrodes 24 a , 24 b so electrical charge can be stored therebetween in the manner of a conventional capacitor. However, unlike a conventional capacitor, the elongate sensor 18 is flexible enough to enable the surfaces 28 a , 28 b of the first and second partially conductive bodies 26 a , 26 b to touch one another when pinched (i.e., as a result of a pinch condition), but not so flexible as to cause contact with one another as the closure panel ordinarily closes. The flexibility of the elongate sensor 18 can be controlled by its cross sectional configuration, including controlling the thickness of the casing walls and the thickness of the partially conductive bodies 26 a , 26 b.
Referring additionally to FIG. 3 , the anti-pinch assembly 10 includes a controller 50 connected to the two electrodes 24 a , 24 b that measures the resistance R between the electrodes. The resistance R will be very high when the partially conductive bodies 26 a , 26 b are separated from each other by the air gap 22 , and will substantially reduce in magnitude if a portion of the partially conductive bodies 26 a , 26 b contact one another. Thus, the elongate sensor 18 and anti-pinch assembly 10 is capable of functioning as a fail-safe contact pinch strip.
In addition to functioning as a contact pinch strip, the elongate sensor 18 also functions as a non-contact capacitive sensor, and is utilized by the controller 50 to measure a capacitance of a field extending through the aperture 14 . In the illustrated embodiment, electrode 24 b functions as a shielding electrode since it is closer to the sheet metal whereby the electric field sensed by electrode 24 a will be more readily influenced by the closer electrode 24 b than the vehicle sheet metal. For best signal quality it is most preferable if the door is electrically isolated from the remainder of the vehicle. A powered sliding door, for instance, may be isolated through the use of non-conductive rollers.
The capacitance of the elongate sensor 18 is measured as follows: The electrodes 24 a and 24 b are preferably charged by controller 50 to the same potential using a pre-determined pulse train. For each cycle the controller 50 transfers charge accumulated between the electrodes 24 a and 24 b to a larger reference capacitor 52 , and records an electrical characteristic indicative of the capacitance of the system. The electrical characteristic may be the resultant voltage of the reference capacitor 52 where a fixed number of cycles is utilized to charge the electrodes 24 a and 24 b , or a cycle count (or time) where a variable number of pulses are utilized to charge the reference capacitor 52 to a predetermined voltage. The average capacitance of the sensor 18 over the cycles may also be directly computed. See, for example, the foregoing publications incorporated by reference herein, which describe various circuitry for carrying out such functions. It will be noted that where an obstruction exists, the dielectric constant between the electrodes 24 a and 24 b will change, typically increasing the capacitance of the elongate sensor 18 and thus affecting the recorded electrical characteristic.
In preferred embodiments, whenever the glass panel 16 is opened the controller 50 creates an opening capacitive reference map 60 by plotting the recorded electrical characteristic against the position (provided by a position sensor such as Hall effect sensor 54 ) of the glass panel 16 . In FIG. 4 , the opening reference map 60 is shown as a graph correlating cycle count against glass panel position. The controller 50 also measures a second capacitance map 62 (the “closing data”) as the glass panel 16 closes that is compared against the opening reference map 60 . Whenever the comparison exceeds a threshold value X for a period of time t, such as at dip 64 , an obstacle is detected. (Cycle count decreases if the capacitance of the sensor 18 increases.)
In order to deal with the possible presence of water on the sensor 18 , the controller 50 adjusts the threshold value based on the relative wetness of the sensor 18 , as shown in plot 80 of FIG. 6 . In this profile, “0” represents a dry seal 18 , and “3” a drenched seal 18 . For a dry seal, no change is made to an initial threshold value X 0 , but for wet seals the threshold value X varies in accordance with the degree of wetness.
The controller 50 determines the degree of wetness based on a calibration wetness profile 70 such as shown in FIG. 5 which is stored in non-volatile memory. The calibration profile 70 is based on empirical data obtained through known conditions of the elongate seal 18 . For instance, plot 72 is based on a dry seal; plots 74 , 75 are based on a seal that is wetted along ⅓ rd and ⅔ rd of its length respectively; and plot 76 is obtained from a completely wet seal all along its length. As will be seen, while the shape of each plot is quite similar, the cycle count differs because the capacitance of the seal 18 differs in each case. More granular data can be obtained, if desired, by further varying the wetting conditions.
Thus, in effecting the obstacle determination, the controller 50 compares the opening reference map 60 against the calibration wetness profile 70 to find the plot 72 , 74 , 75 or 76 that best matches the opening reference map 60 in order to identify the degree of wetness. In order to prevent the situation of the seal 18 becoming wet only after the glass panel is open (which is a more likely scenario with a powered sliding door system), the capacitance of the elongate seal 18 may more preferably be measured at a certain point such as at full opening (or over a certain range of positions) and compared against the capacitance value of these plots 72 , 74 , 75 or 76 at the same position(s) to determine the degree of wetness. Upon closing the glass panel 16 , the controller 50 signals an obstacle when the difference between the closing data 62 and the opening map 60 (at common positions) exceeds a threshold value X=X 0 +D (as a function degree wetness) for a period of time t. When an obstacle is signaled, the controller 50 preferably reverses motor 56 to move the glass panel 16 open.
In a third mode of operation, the controller 50 also monitors the position sensor 54 and/or the current drawn by the motor 56 . In the event of an obstacle, the position sensor will not increment and the current drawn by the motor will spike, thus indicating a pinch condition.
Preferably, the controller 50 utilizes all three modes of obstacle detection—sensor impedance, capacitive sensing and position/current monitoring to detect a pinch condition. The controller 50 may also eliminate the capacitive sensing mode from consideration after two or three serial obstacle detections and rely only on the other two modes in case the capacitive sensing mode has triggered a false positive.
While the above describes a particular embodiment(s) of the invention, it will be appreciated that modifications and variations may be made to the detailed embodiment(s) described herein without departing from the spirit of the invention.
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A method for preventing a vehicular door or window panel from pinching an obstruction extending through an aperture of the vehicle by measuring a capacitance of a field extending through the aperture using a capacitive sensor as a motor drives the panel between the open and closed positions, correlating the measured capacitance to panel position to create closing data, comparing the closing data to a reference map to create a compare value, and detecting an object in a path of the panel as it moves toward the closed position when the compare value exceeds a threshold value. The threshold value is dependent on the relative wetness of the sensor, which is determined by comparing the capacitance of the sensor at predetermined panel positions against a calibration wetness profile.
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BACKGROUND OF THE INVENTION
[0001] In modern fail-safe circuits of the type used, for example, in supply circuits of machine tools, gates, furnaces and medical equipment, dual-channel switching on and off is required so that an inadvertent operation of only one channel will not result in the supply circuit being turned on. It is also required that when one channel fails, such as by contact welding, the other channel is still able to turn off.
[0002] An example of such a fail-safe circuit is found in DE 44 41 171 C1. This known circuit includes two relays with the coil of each relay being connected to a contact of the respective other relay in such a way that the relays will monitor each other, and turning on the supply circuit of the machine being controlled will take place only when both relays function properly. However, the presence of two relays renders the known circuit relatively complex.
[0003] DE 37 05 918 A1 discloses an electromagnetic relay having a magnetic system with a single coil penetrated by an iron piece of an overall U-shaped configuration. One leg of the iron piece is split in two parts so that two parallel magnetic circuits each having an associated clapper-type armature are provided on the same side of the coil. This arrangement is intended to ensure that if the contact driven by one armature undergoes contact-welding, the entire magnetic flux will pass through this armature with the result that the other armature cannot be operated when the coil is energized anew. While this relay allows the switching of two circuits in a somewhat independent fashion, the separation between the circuits is insufficient to satisfy the above-mentioned fail-safe requirements.
[0004] U.S. Pat. No. 4,833,435 describes an electromagnetic relay having a magnetic system with two separate U-shaped iron pieces extending in parallel through a common coil. Each iron piece is part of an individual magnetic circuit for operating an armature actuating a corresponding contact couple. The arrangement is intended to make sure that when one of the contact couples becomes welded, the other one can still open. This prior-art magnetic system suffers from high coil loss and from heat problems resulting therefrom.
[0005] AT 221 148 B discloses an electromagnetic relay with a coil surrounded by a shell-type two-piece yoke. Either yoke piece is formed of sheet iron by stamping and bending. Integrally formed with the yoke pieces are lugs which extend in parallel through the interior of the coil. Either yoke piece is provided with one or more clapper-type armatures which operate in synchronism upon energization of the coil. This type of relay is neither intended nor suited for the type of two-channel operation of fail-safe switching circuits referred to above.
SUMMARY OF THE INVENTION
[0006] It is an object of the invention to overcome at least part of the drawbacks existing with comparable prior-art magnetic systems for electromagnetic relays. It is a more specific object to provide a magnetic system for a relay which is suited for use in a fail-safe switching circuit at small coil losses.
[0007] To meet this object, the invention provides a magnetic system for an electromagnetic relay, comprising a coil arrangement defining a coil axis, and at least two magnetic circuits, each magnetic circuit including an iron piece and an armature, for operating an associated contact system, wherein the iron pieces are magnetically separated and extend parallel to the coil axis through the entire length of the coil arrangement, wherein the spacing between the iron pieces inside the coil arrangement is substantially smaller than the largest cross-sectional dimension of any one of the iron pieces.
[0008] In the present specification, the term “iron piece” is used to designate the overall structure of that component of the magnetic system which includes a portion (“core”) extending inside and through the relay coil or coils, and portions (“yokes”) extending from the coil and cooperating with a relay armature.
[0009] Due to the close arrangement of the iron pieces inside the coil arrangement, a small coil cross-section, thus small coil losses, can be realized, essentially all of the magnetic flux produced by the coil arrangement is coupled into the magnetic circuit and available for actuating the armatures, and stray fluxes are largely avoided.
[0010] Surprisingly, it has turned out that inspite of the close arrangement of the iron pieces, the magnetic circuits are sufficiently uncoupled to obtain the kind of independent switching behavior of the contact systems operated by these circuits that is required for fail-safe circuits.
[0011] The small coil loss which results from the small cross-section of the coil arrangement and the fact the magnetic flux is used by more than one magnetic circuit, and the reduction of stray fluxes lead to the further advantage that heat problems are reduced.
[0012] In accordance with a preferred embodiment, the iron pieces are shaped and disposed relative to each other so as to minimize the ratio of their overall circumference to their total area. The overall cross-section encompassing the iron pieces and the spaces therebetween is preferably square or, ideally, circular, thereby optimising the efficiency in making maximum use of the magnetic flux produced by the coil arrangement.
[0013] In another embodiment, the magnetic circuits lie in planes which are defined by the coil axis and the respective one of the armatures and are equi-angularly distributed round the coil axis. This results in a spatially uniform distribution of the magnetic flux, thus in a further optimization concerning coil losses.
[0014] It is of advantage for the use of the magnetic system in many relay applications if each magnetic circuit contains a permanent magnet.
[0015] In another embodiment, each armature is substantially H-shaped and mounted for pivotal movement about a bearing axis extending perpendicular to the coil axis, and includes two armature plates constituting parallel legs of the H-shape, with a permanent magnet being disposed between these legs. Coupling the magnetic flux of the coil to the individual magnetic circuits is thus facilitated.
[0016] Preferably in this embodiment, two magnetic circuits are provided, the bearing axes of the armatures are coaxial, and their permanent magnets are oppositely magnetized. Forces generated on actuation of the magnetic system are thereby balanced.
[0017] In yet another embodiment, each magnetic circuit includes a permanent magnet extending substantially parallel to the coil axis between ends of a C-shaped iron piece, the permanent magnet having an intermediate pole and two end poles of a polarity opposite to that of the intermediate pole, and an armature mounted for pivotal movement at an intermediate location of the permanent magnet.
[0018] In another preferred arrangement, four magnetic circuits are provided which lie in two substantially perpendicular planes.
[0019] In accordance with a further embodiment of the present invention, two magnetic circuits are provided, and the coil arrangement includes two coils adapted to be independently energized, the armatures being so arranged that both of them are actuated only when both coils are energized. In case of energization of only one coil, at most one armature will respond. Faulty operation of a power circuit provided with the relay may be prevented by proper wiring of the relay contact assembly similar to conventional fail-safe circuits. While the magnetic circuits have approximately similar responsiveness, no switching operation takes place if only one coil is energized; i.e., inadvertent energization will have no effect. It is only by energising both coils that both armatures will be operated.
[0020] If the armatures including their associated contact assemblies are different in responsiveness, the additional advantage of a defined attraction sequence of the two armatures is achieved. For instance, the armature exhibiting lower responsiveness may be provided for operating a contact assembly designed to carry load current. At the same time, failure can be detected from fact that the armature with the higher responsiveness operates. Different responsiveness may be realized by different magnetization or spring characteristics or by non-symmetrical coil windings or by combinations of these measures.
[0021] The coil winding process is simplified if the coils are adapted to generate identical magnetic fluxes. Different coils, on the other hand, would permit varying the excitation necessary to hold the relay in its operative condition.
[0022] In accordance with another embodiment, at least one of the coils is adapted to generate a magnetic flux sufficient to hold both armatures in their operative positions. In this case, the relay may be operated such that the holding current required for the armatures is reduced and, consequently, loss and heat generation may also be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] An embodiment of the invention will now be explained with reference to the accompanying drawings in which:
[0024] [0024]FIGS. 1 a to 1 e are cross-sectional views of magnetic coils and iron pieces extending therethrough;
[0025] [0025]FIG. 2 is a perspective schematic view of a magnetic system of the invention in the rest condition;
[0026] [0026]FIG. 3 shows the magnetic system with both coils energized;
[0027] [0027]FIG. 4 shows the magnetic system with only one coil energized;
[0028] [0028]FIGS. 5 and 6 are schematic exploded views of a magnetic system having two rotary armatures;
[0029] [0029]FIG. 7 is a perspective view of the magnetic system of FIGS. 5 and 6 in the assembled condition;
[0030] [0030]FIG. 8 is an end view, partially in cross section, of the magnetic system of FIG. 7;
[0031] [0031]FIG. 9 is a schematic view of a polarized magnetic system having four armatures; and
[0032] [0032]FIG. 10 is a schematic view of a polarized magnetic system having two armatures.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] [0033]FIG. 1a schematically illustrates a case where two relays are used, each including an iron piece 15 , 16 of square cross-section, an encasing 17 of synthetic resin, and a coil 18 . With a given number of ampere-turns of the coil 18 for operating a given contact system, and a corresponding cross-sectional area of each iron piece 15 , 16 (which area is dimensioned so that saturation is avoided), each coil is assumed to draw a power of 500 mW, which results in a total power of 1000 mW.
[0034] [0034]FIG. 1 b illustrates the situation with a prior-art relay such as known from U.S. Pat. No. 4,833,435. The considerable spacing s between the iron pieces 15 , 16 results in the coil 18 requiring a power that is not smaller than in the case of two separate coils as shown in FIG. 1 a, and may actually reach up to 1200 mW.
[0035] [0035]FIG. 1 c diagrammatically illustrates a structure according to the present invention in which two iron pieces 15 , 16 of square cross-section are disposed close to each other to result in a coil 18 of an overall rectangular cross-section and a power of approximately 650 mW.
[0036] The arrangements of FIGS. 1 d and 1 e are further optimized in that the cross-section of the coil, thus the power drawn by the coil, is further reduced even though the cross-sectional area of each iron piece remains the same. FIG. 1 d shows two, iron pieces 15 ′, 16 ′ of rectangular cross-section which result in an overall square cross-section and in a power of the coil 18 of about 625 mW, while the overall circular cross-section of the iron pieces 15 ″, 16 ″ (as shown in FIG. 1 e ) result in a coil 18 having a power requirement of only 595 mW.
[0037] In the structures schematically illustrated in FIGS. 1 a to 1 e, it has been assumed that the magnetic flux passing through each iron piece is always the same, The arrangements according to the present invention illustrated in FIGS. 1 c to 1 e result in a coil of minimum cross-section, thus minimum coil loss.
[0038] Embodiments of electromagnetic relays using the magnetic system of the present invention will now be described.
[0039] The magnetic system illustrated in FIG. 2 comprises two iron pieces 20 , 21 the intermediate portions of which extend in parallel at a mutual spacing s and together pass through two coils 22 , 23 disposed along the same axis. In the embodiment, the two coils 22 , 23 are wound on a common bobbin 24 including an intermediate insulating flange 25 . The legs 26 , 27 of the iron piece 20 which project from the bobbin 24 and the corresponding legs 28 , 29 of the iron piece 21 extend in opposite directions, with their ends bent upward to form pole shoes 30 . . . 33 .
[0040] A rotary armature 34 is mounted between the pole shoes 30 , 31 of the iron piece 20 for rotation about its vertical centre axis. In the rest condition of the magnetic system illustrated in FIG. 2, where the coils 22 , 23 are not energized, the large armature pole faces 35 , 36 of the armature 34 engage the pole shoes 30 , 31 of the iron piece 20 . Similarly, a rotary armature 37 is mounted between the pole shoes 32 , 33 of the other iron piece 21 for rotation about its vertical centre axis, the large armature pole faces 38 , 39 of the armature 37 in the rest position engaging the pole shoes 32 , 33 .
[0041] In the present embodiment, the coils 22 , 23 as well as the iron pieces 20 , 21 are of identical structure and arranged symmetrical to each other. Further, the armatures 34 , 37 are identically structured and arranged, but the armature 34 has a higher responsiveness than the armature 37 . This will be discussed in detail below in conjunction with FIG. 4. Alternatively, and depending on the requirements of the particular application, the iron pieces 20 , 21 and the coils 22 , 23 may be non-symmetrical.
[0042] In the position illustrated in FIG. 3, both coils 22 , 23 are energized. Their magnetic fluxes, which have the same direction and intensity, are distributed to both iron pieces 20 , 21 so that one-half of the entire magnetic flux generated is available for operating either one of the armatures 34 , 37 . Due to the forces acting between the pole shoes 30 , 31 and the small armature pole faces 40 , 41 of the left-hand (in FIG. 3) armature 34 , and between the pole shoes 32 , 33 and the small armature pole faces 42 , 43 of the right-hand armature 37 , respectively, the armatures have been rotated counter-clockwise and now take the positions indicated in FIG. 3.
[0043] [0043]FIG. 4 illustrates the condition in which only coil 22 or only coil 23 has been energized. As before, the magnetic flux generated by the energized coil 22 or 23 is distributed substantially equally to the two iron pieces 20 , 21 .
[0044] In the present embodiment, the higher responsiveness assumed for the left-hand armature 34 is obtained by the fact that the permanent magnets 46 , 47 , which are disposed between two armature plates 44 , 45 and hold the armature 34 in the rest position, are smaller or weaker than the permanent magnets 48 , 49 provided at corresponding locations in the right-hand armature 37 .
[0045] The magnetic fluxes generated by the coils 22 , 23 and the strength of the permanent magnets 46 . . . 49 are chosen so that, upon energization of only one coil 22 or 23 , only the left-hand armature 34 having higher responsiveness will be operated whereas the less responsive right-hand armature 37 will remain in its rest position. This switching state may be detected, for instance, by contacts (not shown) which are operated by the armatures. Operation of such contacts is through actuators (not shown) which bear against actuating elements 50 . . . 53 formed on the armature.
[0046] Alternatively, different responsiveness may be obtained by the use of different spring loads instead of providing the armatures 34 , 37 with permanent magnets 46 . . . 49 of different strengths.
[0047] As a result of the non-symmetry in the responsiveness of the two rotary armatures 34 , 37 explained with reference to FIG. 4, only one of them will respond when only one of the coils 22 , 23 is energized, as may occur due to failure. As a further result of this non-symmetry, when the energization of both coils 22 , 23 commences, it is first the left-hand armature 34 and only thereafter the right-hand armature 37 that is rotated to the operative position. This behavior may be used to cause the contact couple, which switches the load current, to be actuated by the later operated armature 37 .
[0048] If, upon energization of both coils 22 and 23 , both rotary armatures 34 and 37 have been moved to their operative positions illustrated in FIG. 3, one of the coils 22 or 23 may be turned off. The reduced magnetic flux generated by the coil remaining energized is sufficient to hold the armatures 34 , 37 in their operative positions. Alternatively, the magnetic flux of either one of the coils may be reduced by closing contacts which place resistors in series with the coil energising circuits, thereby reducing power dissipation.
[0049] The magnetic system of FIGS. 5 to 8 comprises a coil 59 with an H-shaped coil core 61 , 62 extending through a bobbin 60 . The parts of the iron pieces 61 , 62 extending through the coil 59 are parallel and at a small spacing s. As viewed in FIG. 5, the two parallel legs of the iron piece 61 form an upper pair of front coil pole surfaces 63 , 66 and an upper pair of rear coil pole surfaces 64 , 65 ; the legs of the iron piece 62 form a lower pair of front coil pole surfaces 63 ′, 66 ′ and a lower pair of rear coil pole surfaces 64 ′, 65 ′.
[0050] The coil 59 is surrounded by a two-part coil case the upper part 67 of which has an upward extending journal 68 , whereas the lower half 67 ′, which has a shape identical to that of the upper half 67 , has a downward extending journal 68 ′ which is coaxial with the journal 68 . Upper and lower armatures 70 , 70 ′ of a somewhat H-shaped overall configuration are mounted for pivotal movement on the respective journals 68 , 68 ′.
[0051] The armature 70 comprises two armature plates 71 , 72 (compare FIG. 8) which form the parallel legs of the H shape and sandwich two permanent magnets 73 , 73 ′. The armature components 71 to 73 are largely surrounded and held together by a casing 74 of synthetic material.
[0052] The left-hand end of the front armature plate 71 , as seen in FIGS. 5 to 7 , projects downward from the casing 74 and constitutes a large armature pole surface 75 , whereas the left-hand end of the rear armature plate 72 is exposed only in a short portion and forms a small armature pole surface 78 . Similarly, the right-hand end of the armature plate 72 projects downward from the casing 74 and forms a large armature pole surface 76 , while the right-hand end of the armature plate 71 is exposed only in a short portion and forms a small armature pole surface 77 . In the assembled condition, the large armature pole surfaces 75 , 76 , which face the longitudinal centre plane of the armature 70 , oppose the upper coil pole surfaces 63 , 64 of the iron piece 61 , and these surfaces have approximately the same size.
[0053] The lower armature 70 ′ is formed identically with respect to the upper armature 70 , with the large armature pole surfaces 75 ′, 76 ′, which face the longitudinal centre plane of the armature 70 ′, oppose the lower coil pole surfaces 63 ′ and 64 ′, respectively, of the iron piece 62 . The identical shape of the two armatures 70 , 70 ′ results in opposite polarizations of the permanent magnets 73 , 73 ′, as indicated in FIGS. 6 and 8.
[0054] As will be apparent from the above description, the magnetic system of FIGS. 5 to 8 constitutes two magnetic circuits, one of which includes the iron piece 61 with the upper coil pole surfaces 63 , 64 , 65 and 66 , and the upper armature 70 , and the other one of which includes the iron piece 62 with the lower coil pole surfaces 63 ′, 64 ′, 65 ′ and 66 ′, and the lower armature 70 ′. The magnetic circuits thus constituted are in planes distributed by 180° around the coil axis (i.e. in the same geometric plane, in this embodiment).
[0055] The embodiment of FIGS. 5 to 8 relates to a monostable magnetic system. In the rest position shown in FIG. 7, with the coil 59 being de-energized, the large armature pole surfaces 75 , 76 abut the upper coil pole surfaces 63 , 64 , and the large armature pole surfaces 75 ′, 76 ′ abut the lower coil pole surfaces 63 ′, 64 ′. When the coil 59 is energized so as to produce a S pole at the coil pole surfaces 63 , 63 ′, 65 , 65 ′ and a N Pole at the coil pole surfaces 64 , 64 ′, 66 , 66 ′, the two armatures 70 , 70 ′ are pivoted in opposite directions into their operative positions in which the small armature pole surfaces 77 , 78 of the armature plates 71 , 72 abut the coil pole surfaces 65 , 66 , and the small armature pole surfaces 77 ′, 78 ′ of the armature plates 71 ′, 72 ′ abut the coil pole surfaces 65 ′, 66 ′.
[0056] The movement of the armatures 70 , 70 ′ may be transferred to sets of contact springs of an electromagnetic relay at the locations indicated by big arrows in FIG. 7. The figure assumes that each armature 70 , 70 ′ actuates two contact springs, for instance in such a manner that one relay contact is open and one is closed in either position of the armature.
[0057] When the coil 59 is switched off, the armatures 70 , 70 ′ will return to their rest positions shown in FIG. 7, because the magnetic system is monostable and the attractive forces between the coil pole surfaces 63 , 64 , 63 ′, 64 ′ and the large armature pole surfaces 75 , 76 , 75 ′, 76 ′ are substantially greater than those between the coil pole surfaces 65 , 66 , 65 ′, 66 ′ and the small armature pole surfaces 77 , 78 , 77 ′, 78 ′.
[0058] The above-mentioned opposite rotation of the two armatures 70 , 70 ′ upon energization and de-energization of the coil 59 results in a compensation of forces and moments occurring in the magnetic system, so that no forces are transmitted to the outside when the system is actuated.
[0059] In a modification not shown, the permanent magnets provided in the armatures may be polarized in the same direction so that the armatures rotate in the same sense when the coil is energized. In this case, the two armatures may be ganged.
[0060] The schematic view of FIG. 9 relates to a magnetic system which may have the same principal structure as shown in FIGS. 5 to 8 , but has four rotary armatures 80 , 80 ′, 81 , 81 ′ disposed around the coil axis at angles of 90° each. As illustrated, each armature has two armature plates 82 sandwiching a permanent magnet 83 .
[0061] Axially extending through the coil 84 are four C-shaped iron pieces 85 , 85 ′, 86 , 86 ′ the intermediate portions of which have sector shaped cross-sections and together fill the internal cross-section of the coil 84 completely, with the exception of small mutual spaces and a common encasing (not shown). The yoke legs 87 , 87 ′, 88 , 88 ′ extending from the coil 84 perpendicularly to the coil axis are disposed between the ends of the respective armature plates 82 .
[0062] In this case, the magnetic system constitutes four magnetic circuits each of which includes one of the iron pieces 85 , 85 ′, 86 , 86 ′ extending through the same coil 84 , and one of the rotary armatures 80 , 80 ′, 81 , 81 ′. The thus formed magnetic circuits lie in planes distributed 90° around the coil axis (thus lying in two geometric planes).
[0063] In the polarized magnetic system schematically shown in FIG. 10, two C-shaped iron pieces 91 , 91 ′ extend through the coil 90 , with the respective coil pole surfaces 92 , 92 ′ and 93 , 93 ′ facing in opposite directions. The intermediate portions of the iron pieces 91 , 91 ′ disposed inside the coil 90 are shape so that they together form square cross-section as shown in FIG. 1 d.
[0064] A permanent magnet 94 , which is disposed between the ends of the iron piece 91 and extends parallel to the axis of the coil 90 , is magnetized to have a central N pole and one S pole at either end. A rod-shaped armature 95 is pivotally mounted at the centre of the permanent magnet 94 in such a way that, in either end position, a respective one of its ends abuts the respective coil pole surface 92 , 93 .
[0065] Just as in FIGS. 5 and 8, the magnetic system shown in FIG. 10 constitutes two magnetic circuits lying in planes distributed 180° around the coil axis (i.e. lying in the same geometric plane).
[0066] The magnetic system of FIG. 10 is bistable. In the position shown, in which the coil 90 is switched off, the armature 95 is retained in the end position shown by the magnetic flux of the permanent magnet 94 . When the coil 90 is energized so that it generates a N pole at the coil pole surface 92 , the left-hand end of the armature 95 in FIG. 10 is repelled from the coil pole surface 92 and is thrown into the opposite position of abutment at the coil pole surface 93 in which it is retained by the permanent magnet 94 when the coil 90 is switched off.
[0067] The same behavior applies to the lower magnetic circuit, which is identical to the upper one and includes an iron piece 91 ′ with coil pole surfaces 92 ′, 93 ′, a permanent magnet 94 ′ and an armature 95 ′.
[0068] The magnetic system of FIG. 10 may be changed to a monostable system by an off-centre magnetization of the magnets 94 , 94 ′.
[0069] In accordance with a modification not shown, the magnetic system of FIG. 10 may be non-polarized. In that case, the permanent magnets 94 , 94 ′ are omitted and the armatures 95 , 95 ′ are pivotally mounted with one of their ends at the respective coil pole surface, rather than at an intermediate location.
[0070] Instead of arranging two armatures on opposite sides of the coil, as shown in FIGS. 5 to 8 and 10 , or distributing four armatures equi-angularly around the coil axis, as shown in FIG. 9, magnetic systems may be devised with three or more than four magnetic circuits disposed equi-angularly around the coil axis. In each case, the spatially distributed and uniform arrangement of the iron pieces leads to the effect that the total magnetic flux generated by the coil is multiply used and coil losses are minimized. Cross-talk between the magnetic circuits results is negligible, and stray fluxes are minimal.
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A magnetic system for an electromagnetic relay comprises at least two iron pieces 15, 16 extending in parallel through the entire length of one common coil 18, each iron piece being part of its own magnetic circuit for operating an armature which is disposed in this magnetic circuit to operate an associated contact system. The spacing between the iron pieces 15, 16 inside the coil 18 is substantially smaller than the largest cross-sectional dimension of each iron piece 15, 16 in order to make maximum use of the magnetic flux produced by the coil 18 with minimum loss and minimum stray flux.
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FIELD
[0001] Embodiments described relate to oilfield well operations. In particular, applications for cutting and removing a well access line from a well that has been stuck downhole for any number of reasons. The well access line may be wireline, slickline, coiled tubing or any of a host of downhole conveyance mechanisms, generally with a tool or toolstring disposed at a downhole end thereof.
BACKGROUND
[0002] Exploring, drilling, completing, and operating hydrocarbon and other wells are generally complicated, time consuming and ultimately very expensive endeavors. In recognition of these expenses, added emphasis has been placed on well access, monitoring and management throughout its productive life. Well intervention and ready access to well information may play critical roles in maximizing the life of the well and total hydrocarbon recovery. As a result, downhole tools are frequently deployed within a given hydrocarbon well throughout its life. These tools may include logging tools to provide well condition information. Alternatively, these tools may include devices for stimulating hydrocarbon flow, removing debris or scale, or addressing a host of other well issues.
[0003] The above noted downhole tools are generally delivered to a downhole location by way of a well access line. A well access line may include a wireline or slickline cable, coiled tubing, and other forms of downhole conveyance line. Regardless, once delivered downhole, a well application may proceed employing the tool. Subsequently, a winch-driven drum at the surface of the oilfield may be used to withdraw the well access line and tool from the well. Unfortunately, however, the well access line and/or tool often become stuck in place downhole. This may be due to the presence of an unforeseen obstruction, unaccounted for restriction, differential sticking of the tool against the well wall, or a host of other reasons.
[0004] In the case of wireline cable, a weak-point is generally built into the cable head where the tool and cable are joined. Thus, when sticking occurs, the winch may continue to pull uphole on the line until a break occurs at the weak-point. Subsequently, a fishing operation may ensue to retrieve the stuck tool from the well. Unfortunately, slickline, coiled tubing, and other conveyances often lack a built-in weak-point. Thus, at best, continued pulling on the line will only result in an uncontrolled break, generally nearer the oilfield surface. Such an uncontrolled break may leave the well obstructed by thousands of feet of line that will only add to the time, effort, and expense of the follow-on fishing operation. Furthermore, even where a weak-point is built into the assembly, break failure of the weak-point often occurs. This may be due to a design or manufacturing flaw, or other reasons. Regardless the reason, failure of the weak-point to break may result in an uncontrolled break as noted above.
[0005] In the case of wireline or other non-tubing conveyances, cutting bars are often employed in an attempt to avoid uncontrolled breaking of the line. A cutting bar is a pipe equipped with an internal cutting mechanism. The bar may be positioned over the line and dropped vertically into the well. In theory, the bar will drop until it reaches the sticking location, at which point the sudden stopping of the bar will actuate the cutting mechanism and induce a break in the line.
[0006] Unfortunately, employing a cutting bar may still result in breaking the line at a location uphole of the sticking location. This is due to the fact that the described cutting bar technique proceeds blindly. So, for example, in the case of a deviated well, the cutting bar will stop dropping and cut the line as soon as a bend or deviation is encountered which may be nowhere near the targeted sticking location. Similarly, a slight narrowing in the well, or minimal obstruction unrelated to the sticking of the line, may be enough to stop the fall of the cutting bar. Either way, the cutting bar may stop uphole of the sticking location, induce a break in the line, and add tremendous time and expense to the follow-on fishing operation.
[0007] As an alternative to the cutting bar, a timed cutter may be deployed within the well. That is, a cutter equipped with a cutting mechanism that is activated based on a timer may be dropped into the well. In this way, temporary stopping of the cutter, for example, upon encountering a minor obstruction, may not result in activation of the cutting mechanism. Rather, the cutting mechanism may be activated only after a set period of time, presumably after bypassing any such minor temporary obstructions.
[0008] Unfortunately, the use of a timed cutter fails to overcome uncontrolled line breaks in circumstances of deviated wells or in the face of significant well obstructions. In such cases, the activation of the cutting mechanism is still likely to take place well uphole of the sticking location. That is, the mode of cutting remains blind and thus, susceptible to breaking the line well uphole of the targeted sticking location. Furthermore, in the case of coiled tubing, similar cutting mechanisms may be employed that generally involve the initial deployment of a cable interior of tubing so that follow-on cutting techniques may be carried out. However, such techniques remain blind and susceptible to inducing coiled tubing breaks uphole of the targeted sticking location. In fact, in the case of coiled tubing, the cutting techniques generally require cutting of the coiled tubing at the location of the drum in order to deploy the interior cable. As a result, large amounts of coiled tubing are rendered ineffective for future use. Thus, in many cases, the operator may ultimately be left with no better option than to run a blind attempt at cutting the line which runs a significant likelihood of adding several hundred thousand dollars of expense to future fishing and other operations.
SUMMARY
[0009] A cutting tool is provided for cutting a well access line downhole in a well. The tool includes a housing which accommodates an active propulsion mechanism for driving the tool along the well access line to a cut location thereof. A cutting mechanism is also accommodated by the housing in order to achieve cutting of the well access line at the cut location.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side overview of an oilfield with an embodiment of a cutting tool thereat for cutting a non-tubular well access line of a tool stuck in a well.
[0011] FIG. 2 is a side cross-sectional view of the cutting tool of FIG. 1 .
[0012] FIG. 3A is a side cross-sectional view of the cutting tool of FIG. 2 dropped into the well of FIG. 1 about the well access line therein.
[0013] FIG. 3B is a side cross-sectional view of the cutting tool of FIG. 2 striking a bend in the well of FIG. 1 .
[0014] FIG. 3C is a side cross-sectional view of the cutting tool of FIG. 2 propelling along the well access line in a lateral section of the well of FIG. 1 .
[0015] FIG. 4 is a side cross-sectional depiction of the cutting tool of FIG. 2 interfacing a cable head of the tool of FIG. 1 .
[0016] FIG. 5 is an enlarged view of the cutting tool taken from 5 - 5 of FIG. 4 depicted cutting the well access line of FIG. 1 .
[0017] FIG. 6 is a side overview of the oilfield of FIG. 1 with the cutting tool and well access line retrieved from the well thereof.
[0018] FIG. 7 is a depiction of an alternate embodiment of a cutting tool for cutting a well access line in the form of coiled tubing.
[0019] FIG. 8 is a flow-chart summarizing embodiments of employing cutting tools as described in FIGS. 1-7 for cutting well access lines in a well.
DETAILED DESCRIPTION
[0020] Embodiments are described with reference to certain downhole tool operations at an oilfield. For example, primarily wireline based tractor driven logging operations are described throughout. However, alternate downhole operations employing different types of well access line, including coiled tubing, may utilize embodiments of cutting tools as described herein. Of particular note, these cutting tool embodiments may be equipped with a propulsion mechanism configured to actively drive the cutting tools along the well access line to a deliberately targeted cut location.
[0021] Referring now to FIG. 1 , a side overview of an oilfield 105 is shown with a well 180 running through a formation 190 thereat. The well 180 includes a vertical section 181 that transitions into a lateral section 182 as it rounds a bend 195 . In the embodiment shown, a downhole logging tool 130 is driven through the well 180 by way of a downhole tractor 120 to obtain diagnostic information relative to the well 180 . For example, pressure, temperature, flow and other readings may be obtained through such an application.
[0022] The above noted tractor 120 and logging tool 130 are delivered to the depicted downhole location by way of a well access line in the form of a wireline cable 110 . The wireline cable 110 may provide telemetric and powering capacity between the tractor 120 and/or logging tool 130 and surface equipment, such as a processing unit 178 and power unit 179 . As shown, the wireline cable 110 is delivered to the oilfield 105 by way of a wireline truck 175 accommodating the noted equipment along with a drum 177 about which the wireline cable 110 is wound. Additionally, as described in greater detail below, a cutting tool 100 is provided in the event that that the logging tool 130 and/or tractor 120 become stuck downhole in the well 180 .
[0023] The wireline cable 110 is run from the drum 177 to a rig 150 where it is strung about sheaves 152 , 154 and ultimately directed through well access and regulation equipment 155 , often referred to as a ‘Christmas tree’. This equipment 155 includes blowout prevention and other valve mechanisms to allow for the coupling downhole tools 120 , 130 to a cable head 115 at the end of the cable 110 . Such tools 120 , 130 may then be advanced through the well 180 . Indeed, as shown in FIG. 1 , the tractor 120 may be employed to drive the logging tool 130 to the location shown. Thus, the cable 110 traverses the well 180 , eventually terminating at the in the lateral section 182 thereof.
[0024] However, in the embodiment of FIG. 1 , the logging tool 130 is shown stuck in debris 197 . In certain circumstances, this sticking may reach a point that the combined efforts of the tractor 120 and winch-powered drum 177 remain unable to dislodge the logging tool 130 . Thus, cutting of the cable 110 followed by fishing out of the downhole tools 120 , 130 may be in order. However, in cutting the cable 110 , it may be of significance that the cut take place as close to the cable head 115 as possible. In this manner, the well 180 may be substantially free of cable 110 during the subsequent fishing operation. Therefore, in order to help ensure that the cable 110 is cut close to the cable head 115 , the cutting tool 100 may be positioned about the cable 110 and directed into the well 180 toward the cable head 115 as detailed herein-below.
[0025] With added reference to FIG. 2 , a side cross-sectional view of the cutting tool is depicted. The cutting tool 100 is equipped with a line or cable space 215 running there-through to allow the tool 100 to be positioned about the cable 110 and dropped into the well 180 . A blade 240 for cutting the cable 110 is provided for use once the tool 100 is properly positioned downhole. Along these lines the tool 100 is also equipped with an active propulsion mechanism in order to help properly position the tool 100 for the cutting. That is, as shown, the tool 100 includes wheels 200 disposed at the end of extension arms 201 . Thus, at the appropriate time, the wheels 200 may grab onto the cable 110 in the space 215 and drive the tool 100 to the proper downhole location for cutting.
[0026] Continuing with reference to FIG. 2 , the above noted propulsion mechanism is housed within a main housing 250 of the tool 100 along with a clamping mechanism 230 as described further below. Additionally, a power source 225 and locator housing 275 are each coupled to the main housing 250 . The power source 225 may be a conventional battery such as an off-the-shelf lithium battery casing. In one embodiment, up to about 12 volts of power may be provided to the propulsion mechanism from the power source 225 so as to adequately drive the tool 100 downhole as described. Also, as detailed below, the clamping mechanism 230 may be activated to secure the tool 100 to the cable 110 in advance of the cutting thereof. Actuation of this clamping may be powered by the power source 225 or mechanically. Regardless, once clamping of the cable 110 is achieved at the location of the clamping mechanism 230 , cutting of the cable 110 downhole thereof will result in securing of the tool 100 to a portion of the cable 110 that is now retractable about the drum 177 at surface.
[0027] The above noted locator housing 275 may house a locator mechanism such as bearings 277 which are biased by springs 278 . As described below, the locator housing 275 may interface a cable head 115 as the tool 100 reaches a targeted location for cutting the cable 110 . As this interfacing of the locator housing 275 and the cable head 115 occurs, the bearings 277 may be laterally displaced in a manner that effects compression of the springs 278 . In the embodiments described herein-below, this compression of the springs 278 may be utilized as an indicator of tool location. Thus, signaling may be sent by conventional means throughout the tool 100 indicative of tool location. For example, spring compression may be employed as a trigger for actuation of the clamping mechanism 230 , immediately followed by actuation of the cutting of the cable 110 by the blade 240 .
[0028] As shown in FIG. 2 , the blade 240 is retained within a chamber 242 by a membrane 450 (see FIG. 4 ). However, once the tool 100 reaches the cutting location as indicated by the above-noted interfacing, the blade 240 may be fired from the chamber 242 to achieve cutting of the cable 110 . That is, a firing mechanism 244 such as an explosive charge, compressed gas or other conventional source may be employed to fire the blade 240 toward the cable 110 in order to attain cutting thereof. Once this process occurs as detailed below, the cable 110 with tool 100 clamped thereto may be retrieved from the well 180 and a follow-on fishing operation may ensue for retrieval of the cable head 115 and other downhole tools 120 , 130 .
[0029] Referring now to FIGS. 3A-3C , enlarged depictions of the cutting tool 100 making its way down the well 180 and through tortuous sections thereof are shown in greater detail. Of note is the fact that the tool 100 is guided through such well sections without prematurely triggering cutting of the cable 110 . Rather, as traversing the well 180 becomes more challenging, the propulsion mechanism is employed to drive the tool 100 therethrough and toward a proper cut location as shown in FIG. 4 .
[0030] With particular reference to FIG. 3A , the cutting tool 100 is shown dropped through the vertical section 181 of the well 180 . At this point, the tool 100 freely drops with the cable 110 running through the cable space 215 . There is no engagement of the clamping mechanism 130 or the wheels 200 relative to the cable 110 . Indeed, in the embodiment shown, the tool 100 traverses the vertical section 181 of the well 180 without draining any power from the power source 225 (see FIG. 2 ).
[0031] As shown in FIG. 3B , the tool 100 eventually reaches the bend 195 in the well 180 . In the embodiment shown, the impact of reaching the bend 195 may act as a trigger to activate the extension arms 201 of the propulsion mechanism. In this manner, the wheels 200 may engage the cable 110 and begin driving of the cutting tool 100 further through the well 180 . That is, as opposed to triggering a cut of the cable 110 as in the case of a conventional cutting tool, the impact of the sudden stoppage of the depicted cutting tool 100 is to activate engagement of the propulsion mechanism. That is, a conventional motion sensor within the tool 100 may be employed to trigger engagement of the propulsion mechanism in lieu of cutting. Thus, premature cutting of the cable 110 may be avoided.
[0032] As shown in FIG. 3C , the wheels 200 of the propulsion mechanism may be powered by the power source 225 sufficiently to drive the tool 100 around the bend 195 of FIG. 3B . In fact, it is worth noting that no downhole powering of the tool 100 is generally required for dropping the tool 100 through the vertical section 181 of the well 180 or for removing the tool 100 from the well entirely (see FIG. 6 ). Thus, a conventionally available battery pack may sufficiently serve as the only downhole power source 225 for driving the tool 100 .
[0033] Eventually, as depicted in FIG. 4 , the cutting tool 100 may come to the cable head 115 . Thus, a targeted location for cutting of the cable 110 has been reached. That is, a cut of the cable 110 made while the cutting tool 100 interfaces the cable head 115 may avoid leaving any significant amount of cable 110 in the well 180 following the cutting and retrieval operation. As described above, the wheels 200 may act to drive the tool 100 to interface the cable head 115 .
[0034] As shown in FIG. 4 , the cable 110 may terminate at an extension 400 of the cable head 115 . Thus, the extension 400 may be received by the locator housing 275 at the cable space 215 thereof. When this occurs, the bearings 277 may be displaced as described above such that the springs 278 are compressed. As such, locating of the tool 100 at the cut location may be communicated throughout the tool 100 by conventional means. In particular, clamping of the cable 110 by the clamping mechanism 130 may be initiated followed by actuation of cutting. As shown in FIG. 5 , this may include firing of the blade 240 from the chamber 242 and through a retaining membrane 450 toward the cable 110 . Such firing may be achieved through a firing mechanism 244 as described above. In an alternate embodiment, however, firing may be actuated when the propulsion mechanism is prevented from continued downhole advancement (e.g. when sticking is uphole of the cable head 115 ). Nevertheless, the firing takes place following driving by the propulsion mechanism and thus, in a less blind manner than conventional cutting.
[0035] With reference to FIG. 5 , an enlarged view taken from 5 - 5 of FIG. 4 is shown, revealing the cutting of the cable 110 by the blade 240 . In this view, the membrane 450 of FIG. 4 is eliminated as the blade 240 is fired from the chamber 242 . The firing results in the cutting of the cable 110 within the cable space 215 as defined by the main housing 250 of the tool 100 . Thus, while a small segment of cable 110 downhole of the cut may be left, the vast majority of the cable 110 is now free of any downhole sticking (see FIGS. 1 and 6 ).
[0036] Referring now to FIG. 6 , the drum 177 may be employed to remove the severed cable 110 from the well 180 . As such, the well 180 is cleared of any significant cable obstruction. With added reference to FIG. 4 , the removal of the severed cable 110 also removes the cutting tool 100 from the well 180 due to the clamping of the clamping mechanism 230 about the cable 110 . By the same token, the engagement between the extension 400 and the locator housing 275 may be of a matching, however, not a locked fashion. Thus, pulling on the cable 110 by the winding drum 177 may be sufficient to disengage the extension 400 and locator housing 275 so as to allow cable 110 and cutting tool 100 removal from the well 180 . As such, follow-on fishing operations may proceed to remove the stuck downhole tools 120 , 130 without concern over cable interference.
[0037] Referring now to FIG. 7 , an alternate embodiment of a cutting tool 700 is shown. In this embodiment, the tool 700 is particularly configured for cutting well access line in the form of coiled tubing 710 . That is, due to the larger diameter and hallow nature of the coiled tubing 710 , the tool 700 is deployed within the tubing 710 as opposed to being deployed thereabout. In fact, the cutting tool 700 may be configured small enough to allow for introduction to the coiled tubing 710 at a coiled tubing reel at the surface of the oilfield 105 . In this manner, cutting of the coiled tubing 710 at the surface may be avoided, thereby salvaging potentially several thousand feet of tubing 710 for future use.
[0038] Continuing with reference to FIG. 7 , the main housing 725 is coupled to a drop line 711 and positioned within the coiled tubing 710 as shown. In the embodiment shown, the line 711 may have power delivering capacity built therein so as to meet power requirements of the tool 700 . Additionally, given the generally unobstructed nature of a coiled tubing interior, pump assisted driving of the tool 700 may be employed. Indeed, the generally unobstructed nature of the coiled tubing 710 may make premature cutting due to locating error less of a concern. Nevertheless, the main housing 725 is equipped with a propulsion mechanism in the form of tracks 750 which extend outward and engage the interior walls of the coiled tubing 710 . As such, the tool 700 may be stably driven to the downhole cut location.
[0039] Similar to the cutting tool 100 of FIGS. 1-6 , the tool 700 may be advanced through the coiled tubing 710 in a relatively passive manner. For example, depending on the architecture of the well 180 , pump assistance and gravity alone may be employed to drive the tool 700 through the majority thereof. However, motion sensing and/or other conventional mechanisms may also be employed such that the noted tracks 750 are deployed at some point in advance of the downhole cut location.
[0040] In one embodiment, the tool 700 is driven in this manner until a coiled tubing connector head is reached. At this point, an interfacing may be achieved similar to that detailed above for the cutting tool 100 of FIGS. 1-6 . For example, a smaller diameter or other recognizable feature of the connector head may be encountered and employed as a location indicator. Thus, cutting as described below may ensue.
[0041] The cutting tool 700 of FIG. 7 is also equipped with a cutting extension 742 and blade 740 for extending outward and cutting the coiled tubing 710 (see cut 720 ). Due to the secure nature of the tracks 710 compressed against the tubing 710 , a stable cut 720 may be made therein as the extension 742 and blade 740 are rotated about the tool 700 . In an alternate embodiment, the blade 740 serves as a scoring device for scoring of the tubing 710 as opposed to complete cutting. Nevertheless, follow-on uphole pulling on the coiled tubing 710 may be employed to induce a coiled tubing break at the scoring location. Indeed, a corrosive chemical may be sprayed from the extension 742 to enhance the breaking in the coiled tubing 710 . In yet another embodiment, a corrosive alone, without any prior scoring or cutting, may be employed in a manner sufficient to allow uphole pulling to induce the break in the tubing 710 .
[0042] Referring now to FIG. 8 , a flow-chart is shown which summarizes embodiments of employing cutting tools as detailed hereinabove. The cutting tools are initially coupled to a well access line to be cut as indicated at 810 and then passively advanced into the well as indicated at 830 . In the case of wireline or other non-tubular well access this may involve coupling the cutting tool about the line and manipulating well access and regulation equipment such as blow out prevention valving. Thus, the cutting tool may then be dropped into a vertical portion of the well. In the case of coiled tubing, on the other hand, this may involve positioning the cutting tool within the tubing at a coiled tubing reel and employing pump assistance to advance the tool to the vertical portion of the well. Regardless, at this point, the advancement of the tool may be achieved without any active propulsion from the tool itself and thus, is considered herein as ‘passive’ advancement.
[0043] At some point, the tool may reach a bend in the well or other obstruction sufficient to halt passive advancement thereof. A conventional motion sensor within the cutting tool may be employed to detect such a halt. When this occurs, a propulsion mechanism of the tool may be deployed as indicated at 850 to engage the line. As noted above the propulsion mechanism may engage the line by either outward or inward extension, for example, depending upon the type of line and cutting tool involved. Regardless, the propulsion mechanism may thus be employed to drive the tool further downhole as indicated at 870 .
[0044] The tool may be advanced as described above until reaching a cut location. In the case of non-tubing access such as wireline, confirmation of the tool reaching the cut location may be particularly beneficial as detailed hereinabove. Thus, as indicated at 880 , such cut location may be confirmed, for example, based on an interface achieved between the cutting tool and a cable head. Of course, similar location confirmation techniques may also be employed where the well access line is coiled tubing. In any case, once the cut location is attained by the cutting tool, a break may be induced in the line as indicated at 890 .
[0045] Embodiments detailed hereinabove provide cutting tools and techniques that may be employed in manners that enhance certainty and accuracy of well access line cutting. The cutting tools may be employed in manners that need not rely exclusively on timers, motion sensors, or other blind mechanisms for triggering cutting of a well access line. This may be particularly beneficial in the case of non-tubular access cutting where actuation of cutting based on such mechanisms is prone to trigger cutting as a response to downhole obstructions or at a point in time that the cutting tool is caught on such an obstruction. Additionally, in the case of coiled tubing, cutting tools and techniques are detailed which may avoid the cutting of the tubing at the well surface, thereby saving potentially several thousand feet of coiled tubing.
[0046] The preceding description has been presented with reference to presently preferred embodiments. Persons skilled in the art and technology to which these embodiments pertain will appreciate that alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle, and scope of these embodiments. For example, a cutting tool for severing a non-tubular well access line may be employed with an outward extending propulsion mechanism similar to that described for use on coiled tubing. In such an embodiment, the propulsion mechanism may engage a well wall as opposed to the line interior thereof. By the same token, space permitting, a cutting tool for coiled tubing may be employed about the coiled tubing with inwardly extending propulsion mechanism similar to that described herein for use on non-tubular access lines. With modifications such as these in mind, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.
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A cutting tool for cutting a wireline, slickline, coiled tubing, or other well access line stuck downhole in a well. The tool includes a host of features including a propulsion mechanism to aid in delivering the tool to a predetermined cut location of the line. In this manner, the risk of unintended uphole cutting of the line may be minimized. Thus, the time and expense of any follow-on fishing operations to remove tools stuck further downhole may be reduced.
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FIELD OF THE INVENTION
The invention relates to an apparatus for collecting floatable liquids such as oil, gasoline or the like, in particular in the case of oil-contaminated or gasoline-contaminated water surfaces.
BACKGROUND OF THE INVENTION
In the event of accidents involving ships and, in particular, tanker disasters, large quantities of oil can escape and form an oil slick or oil-contaminated sea water on the water surface. All previous measures to extract such oil slicks or oil-contaminated sea water from the water surface have tended to have little effect. For example, it has been the case that the oil slick or the oil-contaminated sea water has been contained by floating barriers, in order then to extract said oil slick or sea water from the water surface. This is only possible when the sea is calm, the extraction volume generally not corresponding to the required quantity. High seas force the oil slick or the oil-contaminated sea water over such floating barriers.
It has also turned out to be the case that the use of chemicals is not very efficient due to the aggravating odor and other resulting phenomena, such as the oil mixture sinking onto the sea bed.
FR 2 673 214 A1 discloses an installation for collecting oil slicks, the oil slicks being extracted in large volumes below the water level by means of an oil-extraction station comprising a plurality of assemblies and units. In a particular embodiment of the generic type from this document (FR 2 673 214, FIG. 7), provision is made for an oil-collecting container which floats in the water and exhibits, on its upper wall sections, a float resting on the water surface. The oil layer floating on the water is guided laterally beneath the float and enters, through openings in the wall sections, into a collecting container. The collecting container itself is connected to a suction line which extracts the liquid which has been received in the collecting container downwards out of said container and leads, via lines, to a ship's boat or the like. This installation has the advantage that the more or less thick oil layer is always collected beneath the float and fed to the oil-collecting container. The buoyancy of the oil-collecting container itself and the inflow surface, for the liquid which is to be taken in, in the collecting container determine the measure or the quantity of the liquid received. In the case of this installation, accordingly, separation of the oil layer from the rest of the water surface can only be carried out with difficulty, which may possibly result in the intake of large quantities of water which is only contaminated to a small extent, and thus impair the efficiency of the installation.
A further installation for absorbing oil slicks is known, for example, from DE 27 21 108 A1. In this extremely large-volume installation, there is located, in the center of a scaffolding structure which has been rendered floatable, a frustoconical housing with lateral inlet openings for receiving the oil-contaminated surface water. Here too, the penetration depth of the inflow openings follows the measure of the immersion depth of the floats located on the outer scaffolding ends. A receiving clearance of defined thickness for an oil slick cannot be adjusted.
See also French Patent Specification FR 24 10 093, which discloses an oil-extraction station which is constructed, in pot form, as a float. In the case of this apparatus, the oil slick is received on the upper side of the floating apparatus via inflow slots. The correct floating position and immersion depth of such an apparatus are accordingly determined by the measure of the oil passing under the upper side.
SUMMARY OF THE INVENTION
The object of the invention is to provide an oil-extraction apparatus which makes it possible for an oil slick or oil-contaminated sea water to be collected in a very specific and thus efficient manner. In this arrangement, the installation is to be designed such that it can collect an oil slick or oil-contaminated water over a large area, with the result that it can be used after tanker disasters in docks, coastal areas, on open seas or land-locked seas or other waters, it also being possible for leaking drilling platforms or damaged oil-supply lines to be treated in a corresponding manner.
The essence of the invention is that the oil-extraction station comprises a float which, to the greatest extent, rests on the water surface and does not penetrate into the water surface, or penetrates only slightly into the water surface, with the result that the oil layer floating on the water surface can, in practice, pass beneath said float. Accordingly, the oil-extraction station, as a result of its volume and as a result of further buoyancy measures, has such an immersion depth that the upper float resting on the water surface forms a type of upper limit for the oil slick which is to be received. The lower limit of the oil slick which is to be received is formed by an additionally provided intake trough, with the result that float and intake trough form a mouth-like opening for the oil layer or the oil slick which is to be received. In this arrangement, the inflow width of said receiving opening is variable, depending on the application.
This measure can result in the oil slick being received by the oil-extraction station in a very specific and thus efficient manner, which oil slick is then directed into a collecting container contained within the oil-extraction station. From there, the oil which has been collected can be transported by means of pumps and extraction lines into an adjacent bunkering boat.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages and details of the invention are explained in more detail in the exemplary embodiments described hereinbelow and can be gathered from the drawings, in which:
FIG. 1 shows a perspective view of an oil-extraction station, partly in section,
FIG. 2a shows a schematic representation of the oil-extraction station according to FIG. 1, partly in section,
FIG. 2b shows a plan view of the upper region of the station according to FIG. 2a,
FIG. 3 shows a side view of the schematic representation of a further exemplary embodiment,
FIG. 4 shows a side view, half in longitudinal section in order to represent further details, and
FIG. 5 shows a connection diagram for the activation of the high-capacity pressure pumps.
DETAILED DESCRIPTION OF THE INVENTION
According to the perspective view in FIG. 1 and the side view in FIG. 2a, the oil-extraction station 1 according to the invention comprises a cylindrical basic body 2 with a large number of inflow openings 3 which are contained in the upper outer surface of said basic body 2 and are designed as horizontal longitudinal slots or circular bores. A chambered or dome-shaped covering cupola 4 closes off the upper part of the cylindrical basic body 2 and exhibits likewise slot-shaped inflow openings 5 which run radially outwards (cf. FIG. 2b). The cylindrical basic body 2 serves as a collecting container 2 for an oil slick 6, on the water surface 7, which is to be disposed of. In its upper region, the oil-collecting container 2 is surrounded by an annular float 8 which is optionally divided into ring segments and exhibits a multiplicity of air ducts 9 in its interior. The air ducts 9 serve as buoyancy chambers and, if appropriate, are configured such that the float 8 rests essentially on the water surface 7 in the manner of a lifebelt. The air ducts 9 may be configured to be inflatable. They may also be filled with other buoyancy means. As can be seen from FIG. 1, the air ducts 9 may comprise a plurality of annular individual chambers which may be filled with air or another buoyancy means to a greater or lesser extent.
The external diameter d 1 of the float is d 1 ≈7 m. The external diameter of the collecting container is d 2 ≈3 m, and its height is, for example h 2 ≈2.5 m. The height of the float 8 is h 1 ≈0.5 m.
Located just beneath the float 8 is a parabolic intake trough 10, of which the upper border 11 is arranged at a defined distance s beneath the float. As can be seen from FIGS. 3 and 4, said gap S can be varied in size, for which purpose use is made of a height-adjustment device 12. The maximum lifting adjustment is represented in FIG. 3 by Δs and is Δs≈250 to 300 mm. The bottom position of the intake trough is designated by 10'.
The height-adjustment device 12 comprises a threaded spindle 13 and a spindle nut 14. The threaded spindle 13 is driven by a drive motor 15 (see FIG. 4).
From FIGS. 1, 4 it can, furthermore, be seen that the intake trough 10 likewise exhibits buoyancy bodies 16 which are designed, for example, as air cushions and, if appropriate, are variable in their volume.
Opening into the oil-collecting container 2 are three extraction pipes 18 which are arranged symmetrically about the center axis of symmetry 17 and reach, with their lower end 19, approximately as far as the closed base 20 of the oil-collecting container 2. High-capacity pressure pumps 21 are integrated into the extraction pipes 18, which pumps serve for the delivery of the oil or of the oil-contaminated liquid collected in the oil-collecting container 2. In the upper region, the extraction pipes 18 project through the covering cupola 4 (cf. FIGS. 1 to 2b) and exhibit, in their upper region, flexible hoses 22 which serve for the flexible connection to further pipelines to a bunkering boat.
Located beneath the closed base 20 of the oil-collecting container 2 is a stabilizer 23 with positioning feet 24. In its upper wall section, the stabilizer exhibits a plurality of infeed bores 25 through which water can penetrate. Equally, its base 26 contains further infeed bores 27 through which water can flow in. The cross-sectionally frustoconical stabilizer 23 is, accordingly, flooded with water and, when the sea is rough, behaves in a manner similar to a downwardly projecting center board. Consequently, the movements of the oil-extraction station are stabilized in rough seas.
Located in the lower region of the cylindrical collecting container 2 is a rudder blade 28 with a cross-rudder screw 29 which serves to stabilize the position of the oil-extraction station.
The oil-extraction station 1 can be transported and fixed in position by transporting and securing eyelets 30.
The extraction pipes 18 are retained in the interior of the collecting container 2 by fastening webs 31 which are fitted with additional vibration dampers 32. Fastening webs 31 with vibration dampers 32 for the three symmetrically arranged extraction pipes 18 are also located above the covering cupola 4. However, the fastening to an inner wall, as is present within the container, is not provided here.
Accordingly, the oil-extraction station 1 according to the invention serves for the large-area and large-volume absorption of oil slicks and oil-contaminated fresh water or sea water beneath the water surface. In this arrangement, the installation is produced in a compact manner and is made up of assemblies, units and auxiliary functional units which are resistant to sea water, acid and fire. In this arrangement, the cylindrical collecting container 2 forms the foundation of the installation and, in accordance with its height h 2 ≈2 to 4 m and its diameter d 2 ≈3 m, receives a large quantity of the oil slick which is to be absorbed. The floating of the oil-extraction station is ensured by the individual buoyancy bodies 9, 16 and by the volume of the collecting container 2 which remains free, the intention being for the float 8 to rest essentially on the water surface in order to form the defined inflow gap s between the float 8 and the intake trough 10. The external diameter d 3 of the intake trough 10 corresponds approximately to the external diameter d 1 of the float 8 (cf. FIG. 2a). However, according to the representation of FIG. 1, it may also be of a somewhat smaller design.
For use, the oil-extraction station is aligned in the water such that the oil slick 6 is always located level with the lower edge 33 of the float 8, i.e. the water surface 7, as it were, forms the lower edge 33 of the float 8. The upper edge or the upper border 11 of the intake trough 10 is adjusted by means of the height-adjustment device 12 such that the gap s corresponds approximately to the thickness of the oil slick 6. In this manner, the oil floating on the water is removed in a very specific manner. The inflow of the oil slick 6 into the inflow gap 39 is identified in FIG. 1 by arrows 34, the gap permitting the oil slick to flow through the inflow openings 3 into the interior of the container (arrow 35). The oil running into the oil-collecting container 2 is transported, in accordance with the arrow 36, by way of the extraction pipe 18 into an associated bunkering boat (arrow 37).
The frustoconical stabilizer (23) has a height h 3 ≈1 m. It prevents the oil-extraction station from capsizing, even in high seas, and provides the entire installation with a stable position adapted to the respective sea conditions.
The upper covering cupola 4 with its inflow openings 5 makes it possible for oil to be received when waves are breaking over it, with the result that, in this manner too, oil or contaminated water can flow into the installation.
According to the representation of the oil-extraction station according to the invention shown in FIGS. 3 and 4, the inflow openings 3 provided in the oil-collecting container 2 may be designed in the form of slots or as bores. They are provided over a height region h 4 , which corresponds approximately to the maximum inner height region h 5 of the intake trough 10. Accordingly, the inner wall section 38 of the intake trough 10 tapers in the form of a funnel to height h 5 , at which the inflow openings 3 are provided. The inflow openings 3 prevent foreign bodies such as driftwood or the like from penetrating into the interior of the oil-collecting container 2.
The height-adjustable parabolic intake trough 10 increases the suction action aimed at the oil slick 6 which is to be received. In particular due to the adjustable gap width s, specifically only such liquid as is contaminated with oil is taken in. The parabolic intake trough 10 is adjusted via roller-mounted prism guides and, in particular, via the adjustment device 12.
The upper edge 11 of the parabolic, adjustable intake trough 10 is always located beneath the water surface 7, with the result that the oil slick 6 is forced to flow through the resulting inflow opening 39 into the oil-extraction station. This results in the installation being force-filled. Additional flooding valves may be used in order to fill the installation. If the oil-extraction station is filled with oil, the pumps 21 are put into operation. The high delivery capacity of the low-lying high-capacity pressure pumps 21 results in a high suction action in the oil-extraction station.
The rudder blade 28 and the cross-rudder screw 29 prevent the oil-extraction station from turning about its own axis in stationary operation or when being towed. The cross-rudder screw 29 may be coupled to a navigation system and controlled remotely or operated manually.
As can be seen from FIG. 4, the upper, outer border of the intake trough 10 may be designed to be bent off slightly at an angle of α≈140° with respect to the outer cone surface. This forms a type of "plate border" which makes it possible specifically for the oil layer to be received.
The pumping operation of the water/oil mixture is a continuous process as long as the cleaning operation is taking place. For this purpose, FIG. 5 shows a connection diagram of the actuation of the high-capacity pumping system.
When the installation is started up, the latter is merely activated by water in a first operation phase (arrow 41), the water 41 being fed from the lower base 42 of the installation via a delivery line 43 to a high-pressure pump 44. Said high-pressure pump 44 produces a constant pressure on the two non-return valves 45, 45a. This prevents the high-capacity pressure pumps 21 from drying out. The high-capacity pressure pumps 21, designed as centrifugal pumps, may be driven hydraulically, electrically or pneumatically.
The first amount of water is pumped back into circulation in the installation. For this purpose, provision is made for a three-way valve 46 which is regulated by a control member 47. The control member measures the density of the medium and controls the three-way valve 46.
As soon as the control member 47 registers taken-in water, the three-way valve is switched such that said water is pumped via lines 48, back to the base 42 of the installation, said base 42 being located within the container some way beneath the contamination surface 57 of the oil (water surface: cf. reference numeral 56).
As soon as the control member 47 registers oil, the three-way valve 46 is, in a second operation phase, switched over and the contaminated oil is pumped, via a separator system 49 designed, if appropriate, as a centrifuge, into a collecting container 50, e.g. a tanker, collecting tank or the like. The control system 47, for differentiating water and oil in conjunction with the separating device, ensures that, as far as possible, optimum separation of oil and water which have been taken in is carried out, with the result that, as far as possible, only taken-in oil is disposed of.
Accordingly, the high-capacity pressure pumps 21 essentially only extract, via the line 51, top-floating oil, the intention being to dispose of this oil. The water located beneath can be disposed of via the additional high-pressure pump 44. Excess water can be pumped to the outside by the installation via the lines 54. Shut-off valves 55 determine the flow direction through the high-pressure pumps 21.
In FIG. 5, a further line 52 is led from the separator system 49 to the base 42 of the installation in order to pump back excess water.
The oil-extraction station according to the invention is not restricted to the exemplary embodiment which has been represented and described. Rather, it also encompasses all specialist developments within the scope of the idea according to the invention.
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An apparatus for collecting floatable liquids such as oil and gasoline, in particular in the case of oil-contaminated or gasoline-contaminated water surfaces. The apparatus includes a collecting container which is vat-like or cylindrical and which is immersed into the water surface; an annular float on which the collecting container is at least partly borne in its upper region; an inlet opening for the liquid which is to be collected and arranged directly beneath the float; at least one delivery pump for transporting the liquid in the collecting container to a disposal station, the float having a buoyancy arrangement such that the float substantially rests on the water surface; a funnel-like intake trough which encloses the collecting container and is located beneath the float, the trough forming, along with the float, a defined intake gap which corresponds to the width of the liquid stream which is to be taken in, the intake gap between the underside of the float and the upper side of the intake trough being variable in its width and being less than or equal to 300 mm.
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[0001] This U.S. Utility patent application claims priority to U.S. Provisional Patent Application Ser. No. 60/678,783, filed May 9, 2005, the content of which is hereby incorporated by reference in its entirety into this disclosure.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to systems and methods for automated processing of devices. In particular, the present invention relates to an automated technique which performs user-defined provisioning steps on a mobile device.
[0004] 2. Background of the Invention
[0005] A mobile or embedded computing device includes some combination of hardware, firmware and software components. Manufacturers typically ship these devices in several different configurations to their customers, such as in raw hardware and firmware with no operating system installed on the device (more rare), or with hardware, firmware and operating system pre-installed (more common). When a first level customer, typically an enterprise information technology (IT) administrator, receives these devices, such customer performs a sequence of installation and configuration steps prior to making these devices available to the end users. The end users may be the employees of the enterprise itself or employees of the enterprise's partners, its customers or suppliers. As used herein and throughout this disclosure, the process of making a device enterprise user ready is defined and described as “provisioning.”
[0006] Mobile devices as received from device suppliers do not have any knowledge or preference setup for the customer's enterprise network. This poses a “catch 22” situation for IT administrators. The devices out-of-the-box cannot communicate with the existing enterprise management infrastructure so there is no way for the existing enterprise management infrastructure to provision these devices. IT administrators have to manually configure the network preferences on each device before the device can start communicating with the enterprise management infrastructure. Besides setting up the network preferences manually, a management agent is manually installed on the device to allow for the device to communicate with the enterprise management infrastructure. This is a very labor intensive and cumbersome process as it has to be performed individually for each device. It is also error prone because the increased need for manual labor involved in this process increases the chances of human error in the process.
[0007] During a typical provisioning process, a number of steps are taken: a device is unpacked; network preferences are manually configured on the device to connect to an enterprise's network; the device is connected to a desktop machine in order to install a management agent on the device; a management agent is installed and configured manually for connecting to an enterprise management server; the management agent on the device is invoked manually; the agent communicates with a management server; the management server performs necessary operations to make the device enterprise-ready; and finally, the device is packaged back and transferred to the end-user of the device. This lengthy and labor-intensive process must be followed for each mobile device received by an enterprise customer before the device is ready to be delivered to one of the specific enterprise users. If the enterprise customer receives dozens or hundreds of such devices at a time, the time required to provision these devices could be so long that the business itself is stifled until all of its personnel receive such provisioned devices.
[0008] Thus, there is a need in the art for a simple and universal technique to provision mobile and embedded devices such that the labor is virtually eliminated while the time and efficiency of preparing such a device for a particular user is greatly improved. Further, such technique should be easy to follow, universally applied to different enterprise customers and applicable to different types of embedded and mobile devices.
SUMMARY OF THE INVENTION
[0009] The present invention is directed toward the field of enterprise mobile device management wherein a computer program running on a host system enables en mass provisioning of mobile devices. In particular, the present invention provides an automated computer program (“provisioning server”) operating at the host system, which, upon detecting the presence of a new mobile device, performs user-defined provisioning steps on the mobile device. The mobile device may be coupled to the host system via a communications pathway, such as a serial, USB, a wireless network or one or more landline or similar networks.
[0010] The present invention, in an exemplary embodiment as an automated device provisioning platform, overcomes the manual and labor intensive process of provisioning mobile and embedded devices for enterprise usage. Further, this invention brings industrial strength reliability to the process of device provisioning. As used herein and throughout this application, the term “automated device provisioning platform” may comprise the following software and hardware components: (1) Provisioning Server—software stack running on one or more host computers; (2) Provisioning Services—software stack running on one or more provisioning stations that can be scattered throughout the globe; (3) Provisioning Nodes—hardware connected to or embedded in provisioning stations via some form of wired connection (Serial, USB, Firewire, etc.) or wireless connection (WiFi, Bluetooth, Infra-red, etc.); (4) Provisioning Agents—software stack running on the devices that are being provisioned, these agents are deployed automatically by provisioning services during the provisioning process or can be pre-bundled with the devices; (5) Management Console—graphical user interface to create and manage provisioning packages (set of provisioning data, operations and flow control); (6) Provisioning database—a persistent database that stores all the configuration and logging information about device provisioning.
[0011] As used herein and throughout this disclosure, the present invention may also be referred to as “provisioning platform” interchangeably. The provisioning platform provides system and methods to create and store automated device provisioning operations. It provides system and methods to automatically detect un-provisioned devices connected to its environment and to provision these devices with the provisioning operations that are stored in its persistent storage. Typical provisioning operations may include, but are not limited to, installation of a provisioning agent on the device, setting up of network preferences on the device, running a custom provisioning application on the device, performing device configuration, installing enterprise applications, etc. Other operations are also possible and within the purview of one having ordinary skill in the art.
[0012] As used herein and throughout this disclosure, a “device” may be any mobile computer that is capable of storing software applications and data. A device is capable of establishing an initial connection to a host computer by any means, including but not limited to serial, Infrared, USB, Fire wire, Ethernet, wireless (802.11) or Bluetooth. Typical, but not limiting, examples of devices that may be provisioned in accordance with the present invention include mobile telephones, pagers, personal data assistants (PDAs), portable email devices (e.g., BLACKBERRY), portable radios, CBs, walkie-talkies, laptop or desktop computers, or the like. A device can further be a storage accessory like a flash memory card or a secure digital card that can be inserted into a mobile computer. A provisioning package can then be executed from this storage accessory to provision the mobile computer.
[0013] As used herein and throughout this disclosure, “provisioning” includes the process of making a mobile computer enterprise ready. In particular, such provisioning is applicable for enterprise usage. When a device is manufactured, it comprises several hardware and firmware components. The device manufacturers then optionally provision an operating system on the device prior to shipping the devices to their customers. When the devices arrive at the customer data center, these devices go through a sequence of manual configuration steps prior to their use by an end user. These steps together are defined as “provisioning.” In general, the following steps are typical: device is unpacked; network preferences are set on the device so that the device can communicate with enterprise network resources; at least one or two applications are installed manually on the device; and other device preferences like date, time, language preferences, etc., are set manually.
[0014] As used herein and throughout this disclosure, a “provisioning package” is a set of related data, metadata, attributes and work flow rules. It is a logical entity whose purpose is to allow IT administrators to define how a device will be provisioned, what applications will be deployed on a device, and what preferences will be set on the device during device provisioning. A provisioning package could typically include one or more of the following: provisioning client; configuration file that directs the provisioning client to perform a sequence of provisioning steps; enterprise specific customer application(s); and customer configuration data like registry values, security settings and location on the mobile computer where applications shall be installed.
[0015] The provisioning platform provides systems and methods to detect the location from where the devices are connecting enabling “location aware” device provisioning. It provides system and methods to define provisioning operations that are unique based on the location from where the device is connecting. For example, if a device is connecting to a provisioning server host that is deployed in San Diego, Calif., network preferences that are local to San Diego offices can be applied to the device. If a device is connecting from Alexandria, Va., then network preferences that are local to the Alexandria offices can be applied to the device.
[0016] The provisioning platform provides system and methods to modify its default behavior. It does so by providing an infrastructure to develop, deploy and execute custom software application both on the device and on the server during a device provisioning operation.
[0017] The provisioning platform provides system and methods to run custom software applications on the device during a device provisioning operation. Further, it provides methods and user interface to create and store provisioning packages within which information about these device specific custom applications is encoded. During a provisioning operation, information about the custom applications is retrieved from the provisioning packages and these custom applications are downloaded and executed on the device.
[0018] The provisioning platform provides systems and methods to enable development and deployment of custom host services on the server end. Further, it provides methods and user interface to store provisioning packages within which information about these custom host services is encoded. During a provisioning operation, information about the custom host services is retrieved from the provisioning packages and such services are executed by the provisioning server on the host.
[0019] In one exemplary embodiment, the present invention is a system for provisioning a device. The system includes a receiving node to communicate with a device to be provisioned; and a processor in connection with the receiving node, wherein the processor automatically detects and provisions the device when the device communicates with the receiving node.
[0020] In another exemplary embodiment, the present invention is a system for provisioning a device. The system includes means for communicating with a device to be provisioned; and means for detecting and provisioning in connection with the means for communicating, wherein the means for detecting and provisioning automatically detects and provisions the device when the device communicates with the means for communicating.
[0021] In yet another exemplary embodiment, the present invention is a method for provisioning a device. The method includes detecting the device; and provisioning the device automatically after detection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 shows the workflow of a conventional manual method of provisioning devices.
[0023] FIG. 2 shows a high level workflow of an automated method of provisioning devices according to one exemplary embodiment of the present invention.
[0024] FIG. 3 shows major components of the provisioning platform according to an exemplary embodiment of the present invention.
[0025] FIG. 4 shows a flowchart of automated device detection according to an exemplary embodiment of the present invention.
[0026] FIG. 5 shows a detailed flowchart of operations that are performed on a device during device provisioning according to an exemplary embodiment of the present invention.
[0027] FIG. 6 shows a basic deployment model of a provisioning platform according to an exemplary embodiment of the present invention.
[0028] FIG. 7 shows an advanced deployment model of a provisioning platform according to an exemplary embodiment of the present invention.
[0029] FIG. 8 shows a globally distributed deployment model of a provisioning platform according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention has many advantages over conventional systems and overcomes the manual, labor-intensive and error-prone process of provisioning mobile and embedded devices for enterprise usage. Use of systems and methods according to the present invention reduces the time required for provisioning, increases accuracy and uniformity of devices provisioned through such a technique, and delivers a dynamic standard that may be easily changed or edited as conditions warrant. Furthermore, the exemplary systems and methods as described herein are applicable to all devices that may need to be provisioned, whether portable or stationary.
[0031] To consider and appreciate the many advantages and advances of the present invention over that of conventional systems, it is helpful to first understand typical and conventional methods for provisioning. An example of a typical conventional method of provisioning a device is shown in FIG. 1 and is characteristically slow and labor intensive. As the flowchart shows, an IT administrator receives a device 120 . These devices are shipped from device manufacturers that do not have any knowledge of the enterprises network settings or applications that the enterprise may want to deploy on the devices. So an IT administrator has to go through a series of steps to make the device enterprise ready (provisioning). The IT administrator unpacks the device 122 , connects the device to a host computer using a cradle 124 and then switches over to the host machine to manually install applications 126 , 128 , 130 . The IT administrator then goes through and manually enters configuration information about network settings and other device preferences on the device 132 . The administrator will then need to test the provisioned device 134 to make sure all the settings were entered correctly and the applications were deployed correctly. This process is typically done manually and one device at a time, therefore subject to errors and inefficiencies reflective of the speed of the person performing the steps. Such person may be performing other tasks simultaneously, thereby resulting in slow rate of provisioning for each device.
[0032] As may be gleaned from the conventional process shown in FIG. 1 , the time required for the provisioning of each device is such that it makes the process of provisioning multiple devices very inefficient and time-consuming. Furthermore, because of the manual nature of the process, each step is prone to errors because of its dependent nature on human control. Also, the person manually performing such steps is prevented from doing other tasks during such manual processing, thus there is opportunity lost to perform or complete other matters. As the present invention shows, the automation of the provisioning process is very helpful in preventing errors that are inherent in manual-intensive processes as well as significantly increasing the efficiency and productivity of the provisioning process, as described below using various non-limiting exemplary embodiments.
[0033] A non-limiting example of the present invention that shows how the present invention is more efficient and more accurate than conventional processes is shown in FIG. 2 . Such an exemplary device-provisioning platform, among other things, automates the labor-intensive conventional process shown in FIG. 1 above. With the automated device-provisioning platform, the IT administrator simply receives 220 and unpacks the device 222 and establishes a connection to the provisioning node 260 (e.g., via serial, cradle, Bluetooth, WiFi or similar type of connection). The automated provisioning platform is configured to apply device preferences and download enterprise applications on the device. Once it detects a connected device, it automatically applies the device preferences and downloads the enterprise applications onto the device 262 . There is no manual intervention required during this entire process. The administrator may then pack the automatically provisioned device 264 and start the process of provisioning other devices 266 if others are in such need. Because the provisioning process is automated, the administrator is free to perform other duties and tasks and does not have to waste time performing manual provisioning. Furthermore, depending on the number of cradles and ports available, multiple devices may be provisioned simultaneously.
[0034] Another exemplary embodiment of the present invention is shown in FIG. 3 as a provisioning platform, and may include a combination of software and/or hardware components. Some of the components of the provisioning platform include provisioning agent 310 , provisioning service 350 , provisioning server 370 and management console 390 . Provisioning server 370 includes a software stack running on one or more host computers 360 . Provisioning service 350 includes a software stack running on one or more provisioning stations 340 that can be scattered throughout the globe. Provisioning nodes 320 (shown in FIG. 6 ) includes hardware connected to or embedded in provisioning stations 340 via some form of connection 600 , wired (Serial, USB, Firewire, etc.) or wireless (WiFi, Bluetooth, Infra-red, etc.), or some combination of both. Provisioning agents 310 include a software stack running on the devices 300 that are being provisioned. The agent 310 is deployed automatically by provisioning service 350 during the provisioning process or can be pre-bundled with the devices 300 . Management console 390 may include a graphical user interface (GUI) to create and manage provisioning packages 378 (set of provisioning operations, flow control and data). Provisioning database 377 includes a persistent storage that stores all the configuration and logging information about device provisioning
[0035] Provisioning server 370 is configured with provisioning package 378 using a management console user interface 390 . A provisioning package 378 , which may be stored in provisioning database 377 , may be a valuable component in provisioning devices because it can store device characteristics such as, for example, make, model, OS version, etc., to uniquely identify a device so that a correct management agent can be deployed on the device. It can also be used to store details of any enterprise specific customized applications that may need to be installed or executed during device provisioning. Further, it can be used to store enterprise specific configuration information that will be applied to the device during provisioning. This configuration information can include specific information such as network preference settings, device settings like time zone, registry values, language preferences, etc. Such information can also include any other device specific configuration settings that is needed for the provisioning agent 310 to start communicating with provisioning server 370 without requiring any further manual key strokes or pen input on the device 300 .
[0036] As shown in FIGS. 3 and 6 , mobile and/or embedded devices 300 that require provisioning are connected to the provisioning node 320 . Provisioning service 350 running on the provisioning station 340 automatically detects the presence of the connected device 300 . It then reads device characteristics and requests provisioning server 370 to return provisioning package(s) 378 that are applicable for this device 300 . Once provisioning package(s) 378 are returned to provisioning service 350 by provisioning server 370 , the provisioning service 350 automatically starts executing the provisioning operations that are encoded in the provisioning package(s) 378 . These steps include, for example, deploying device specific provisioning agent 310 on the device, setting up network preferences, and performing any other customized steps that are set up in the provisioning package 378 like executing customized applications or performing device configuration.
[0037] The provisioning platform can also detect the location 801 from where the device 300 is connecting, as shown in FIG. 8 . Provisioning package(s) 378 can be configured to provision different parameters based on the connection location 801 of the device 300 . For example, if a device 300 is connecting to a provisioning server host that is deployed in San Diego, Calif., network preferences that are local to San Diego offices can be applied to the device 300 . If a device 300 is connecting from Alexandria, Va., then network preferences that are local to Alexandria offices can be applied to the device 300 . All this information is configurable by the IT administrator.
[0038] The provisioning platform provides ways to modify its default behavior. It does so by providing infrastructure to develop, deploy and execute custom software application both on the device 300 and on the server 370 during a device provisioning operation. These methods are discussed in more detail below.
[0039] The provisioning platform makes it possible to run custom software applications on the device during a device provisioning operation. Further it provides methods and user interface to create and store provisioning package(s) 378 within which information about these device specific custom applications is encoded. During a provisioning operation, information about the custom applications is retrieved from the provisioning package(s) 378 and these custom applications are downloaded and executed on the device 300 by the provisioning agent 310 .
[0040] The provisioning platform enables development and deployment of custom host services 379 on the server end. Further it provides methods and user interface to store provisioning packages 378 within which information about these custom host services 379 is encoded. During a provisioning operation, information about the custom host services 379 is retrieved from the provisioning packages and these services are executed by provisioning server 370 on the host.
[0041] As described in summary above, FIG. 3 shows block diagrams of major sub-systems and components that make up an exemplary automated provisioning platform according to the present invention. In this embodiment, there are four typical sub-subsystems that make up the provisioning platform: provisioning agent 310 , provisioning service 350 , provisioning server 370 , and management console 390 .
[0042] Provisioning agent 310 may be a software component that is dynamically deployed on the device 300 that is being provisioned. It implements device specific functionality and works in conjunction with the provisioning service 350 to perform device provisioning operations. Several major components may be included within the provisioning agent 310 . Network configuration component 312 implements the logic for setting up the network preferences on the device 300 . File download component 314 implements the logic for downloading files including new applications on the device 300 . Application execution component 316 implements the logic for executing custom applications on the device 300 while the device is being provisioned. Device configuration component 318 implements the logic for configuring device attributes that are defined in the provisioning package 378 .
[0043] Provisioning service 350 acts as a software sub-system that executes on a provisioning station 340 , which may be a host computer or other similar machine that has appropriate connectivity accessories. The device(s) 300 establish connection to the provisioning machine 340 via an established method, like serial cable, cradle, USB cable, Bluetooth, infrared, WiFi or other methods.
[0044] One of the roles of the provisioning service 350 is to enable “location aware” device provisioning. In “location aware” device provisioning, different provisioning operations can be performed based on the location from where the device is connecting. For example, provisioning services running in Tempe, Ariz. and Boston, Mass. can be configured with different location specific device configurations like network settings, date, time zone, language preferences, etc.
[0045] Provisioning service 350 may have a number of components, a few exemplary embodiments of which are described herein but others are also possible and within the purview of one having ordinary skill in the art. Port monitoring component 352 continuously monitors all the active ports on the provisioning station 340 . When it detects a device 300 on any of the active ports it invokes and passes control to the device type detection component 354 . Device type detection component 354 reads device attributes from the connected device 300 . It then communicates with the provisioning server 370 to check if the device 300 that is connected is supported by the provisioning server 370 . If the device 300 is supported, then it fetches a provisioning package 378 from the provisioning server 370 . It then invokes and passes control to the provisioning package deployment component 356 . Provisioning package deployment component 356 implements the logic for execution of the operations that are encoded in the provisioning package 378 . The first operation it performs is the deployment of provisioning agent 310 on the device 300 that is being provisioned.
[0046] Provisioning package deployment component 356 then performs one or more operations depending on how the provisioning package is configured. For example, it can install any applications that are in the provisioning package 378 on to the device 300 . It can also perform network preferences setup on the device 300 . It also can execute custom or standard applications if any such applications are configured to be executed. Finally, it can perform device configuration.
[0047] Provisioning server 370 may be in the form of a software sub-system that executes on a provisioning server host 360 . The provisioning server 370 may perform a number of functions, some exemplary ones including, but not limited to: enabling centralized command and control for managing all provisioning services 350 ; enabling creation and management of provisioning packages 378 ; facilitating execution of provisioning packages 378 in concert with provisioning services 350 ; enabling creation of custom host services 379 by exposing well defined application programming interfaces (APIs) and providing registration mechanisms for such custom host services 379 ; managing execution of all custom host services 379 and facilitating communications between custom host services 379 and provisioning services 350 ; and managing centralized logging and reporting 376 .
[0048] Considering the number of different functions that may be performed by provisioning server 370 , various components may also be incorporated within its structure of software package. Some of these components are described in more detail herein, but such components are merely exemplary and additional components may be added or included, as is within the purview of one having ordinary skill in the art.
[0049] Provisioning service manager 371 manages the life cycle of all provisioning services 350 . It enables registration of provisioning services 350 with the provisioning server 370 using management console 390 . It launches provisioning services 350 and then processes all communications between the provisioning services 350 , provisioning server 370 and custom host services 379 . The provisioning service manager 371 further performs logging of events generated from provisioning services 350 .
[0050] Provisioning package creation component 372 manages the creation and modifications of provisioning packages 378 . It uses provisioning rules and flow creation component 375 to format valid provisioning packages and then stores the provisioning packages 378 in the provisioning database 377 .
[0051] Provisioning package execution component 373 is used by the provisioning service manager 371 to facilitate execution of provisioning packages 378 .
[0052] Custom service registration and execution component 374 enables registration of custom host services 379 with the provisioning server 370 . It also invokes custom host services when requested by provisioning service manager 371 and manages all subsequent communications between the custom host services 379 and provisioning service manager 371 .
[0053] Logging and reporting component 376 manages logging of information from all provisioning platform components and facilitates generation of reports. Provisioning database 377 , as described above, is a persistent data store for all configuration information that is required for a smooth operation of the automated provisioning platform. It also stores the provisioning packages.
[0054] Provisioning package 378 has been described in various uses above. It enables creation of unique provisioning rules and operations for each type of device. It further contains data, rules and work flow for provisioning a device. Major bits of information that are encoded in the provisioning package could include, but are not limited to: the types of applications that needs to be deployed on a device being provisioned; the network preferences which should be applied to the device being provisioned; the types of other device configuration settings that need to be applied to the device being provisioned; and whether and type of any application that needs to be executed on the device while the device is being provisioned.
[0055] Custom host service 379 may be in the form of a custom software or hardware component that is created by using APIs exposed by the provisioning server 370 . Any custom logic can be implemented in this component. A basic advantage of enabling custom host service 379 is to allow the automated provisioning platform to integrate with existing enterprise computing infrastructures. Other advantages are also possible and evident to one having ordinary skill in the art.
[0056] Management console 390 is a graphical user interface software component that enables management of various components of the automated provisioning platform. Among others, the management console 390 can provide user interfaces for various components. Exemplary, but not limiting, functions include starting/stopping provisioning services 350 , creating/editing/deleting of provisioning packages 116 , registration of custom host services 379 with provisioning server 370 , and real-time view of all major activities going on within the automated provisioning platform.
[0057] As shown and described above with respect to FIG. 3 , the exemplary embodiment presented may have a number of different components, each component capable of one or more functions. Furthermore, not all components are necessary for the proper functioning of the provisioning system or process, and the role of each component may be changed to perform additional or less functions. Ali such variations are within the scope of the present invention and within the purview of one having ordinary skill in the art.
[0058] As the various components of an exemplary system according to the present invention were described above with respect to FIG. 3 , how such components interact together to result in the provisioning of a device is now presented in various exemplary embodiments. One such exemplary flow diagram is presented in FIG. 4 , which shows how an exemplary automated provisioning platform detects a newly connected device and determines the device type. Provisioning service 350 is initiated 420 on the provisioning station 340 . Provisioning service 350 starts monitoring 422 the provisioning nodes 320 . When a device 300 is connected 424 to the provisioning node 320 , the provisioning service 350 detects 426 the newly connected device 300 . It then reads device characteristics 428 using appropriate protocols. Once it has obtained the device characteristics, it communicates with the provisioning service manager 371 component of the provisioning server 370 to obtain a provisioning package 378 that is defined for the device that just connected 430 . The provisioning server 370 makes this decision based on the device characteristics that were passed to it by the provisioning service 350 . Once the provisioning service 350 has the provisioning package information, it starts the step of provisioning the device 432 .
[0059] Once the provisioning platform detects the device 300 and determines the device type and looks up to obtain the appropriate provisioning protocol, the next series of automated steps are used to provision the device. FIG. 5 shows a flowchart of exemplary operations performed by an exemplary provisioning service 350 during device provisioning. Continuing from FIG. 4 , the provisioning service 350 retrieves provisioning agent 310 from the provisioning package 378 and installs it on the device 300 in step 540 . It then retrieves a sequence of operations 542 to perform the provisioning process from the provisioning package 378 . The provisioning service 350 starts processing the operations in a proper sequence 544 . It checks to see if the operation is for an application download 546 and, if so, then fetches all of the required application files 548 from the provisioning package 378 . It then copies all the files to the device 300 using the provisioning agent 310 that is now resident on the device 300 .
[0060] In the next step, the operation is checked for setting up the network 550 preferences on the device 300 . If so, then information and data relating to network preferences 552 are retrieved from the provisioning package 378 . It then requests the provisioning agent 310 resident on the device 300 to apply the network preferences 554 . The next step is to determine whether the operation is for executing an application on the device 556 . If true, it fetches information and command line options for the application that needs execution 558 from the provisioning package 378 . It then requests the provisioning agent 310 resident on the device 300 to execute the application 560 . The next step is to check if the operation 562 is for executing a custom host service 379 . If so, information is retrieved 564 about the custom host service 379 from the provisioning package 378 . It then requests the provisioning service manager component 371 of the provisioning server 370 to start execution 566 of the custom host service 379 . The provisioning service repeats the above flow as needed 568 until all operations encoded in the provisioning package are executed. Such process is automated so as to prevent the necessity for manual interaction with an administrator. Furthermore, such process may be performed on multiple devices 300 in an area where little to no human supervision is required, thereby allowing administrators to perform other duties during such program loading.
[0061] FIG. 6 shows a basic deployment model of the automated provisioning platform according to an exemplary embodiment of the present invention. In this basic deployment model, all of the components of the automated provisioning platform can be located in one physical location. The provisioning server host and the provisioning station can be a single host computer or can be separate computers. In this deployment model, a device 300 is connected to the provisioning node 320 using some form of communication protocol 600 (Serial, USB, Firewire, Bluetooth, WiFi or other). A provisioning node 320 is typically hardware equipment and can be a number of conventional tools, such as, for example, one or more serial cables, USB cables, Bluetooth devices (either external or embedded within the provisioning station), Firewire ports, cradles (serial/USB/Bluetooth/Firewire/Ethernet), WiFi router/hubs that are connected to the provisioning station using appropriate cabling, or the like.
[0062] Provisioning node 320 is connected 610 to the provisioning station 340 using appropriate cables depending on the type of provisioning nodes used. In certain cases, the provisioning nodes 320 can be embedded within the provisioning stations 340 (e.g., a Bluetooth based provisioning node). The provisioning station 340 , the provisioning host 360 and the provisioning database 377 can be hosted on the same physical host computer or machine. If they are hosted on the same host machine, there are no limited connectivity requirements between these components. In cases where these components are hosted on separate host machines, they can be connected 620 , 630 via a standard TCP/IP based protocol.
[0063] FIG. 7 is another exemplary embodiment of the present invention shown in a system diagram and including an advanced deployment model of the entire automated provisioning platform. This model is similar to that shown in FIG. 6 and further enables provisioning of multiple devices simultaneously. In this model, multiple provisioning nodes 320 are configured with the provisioning station 340 . Using this process, multiple devices 300 can be connected to the provisioning station 340 via provisioning nodes 320 and provisioned concurrently.
[0064] FIG. 8 is a system diagram showing a globally distributed deployment model of an automated provisioning platform according to another exemplary embodiment of the present invention. This deployment model enables provisioning of multiple devices 300 concurrently and geographically located anywhere in world. To enable this distributed model of automated device provisioning, the provisioning stations 340 are distributed to various locations 801 where the devices will be provisioned. The provisioning stations 340 are connected to the provisioning server host 360 and provisioning database 377 located in a central location 800 using standard TCP/IP connection 620 . This distribution model also enables “location aware” device provisioning. The provisioning services 350 running on the provisioning stations 340 are location aware and provisioning packages 378 can be encoded to perform location specific provisioning operations. Thus, multiple devices may be provisioned simultaneously at different locations throughout the globe, with the process running efficiently as each provisioning station 340 communicates with the central provisioning database 377 to retrieve information specific to the device 300 and location 801 of provisioning. Optionally, a device 300 at one location may be provisioned with the necessary data and information for another location by accessing such other information in the provisioning database 377 at the central location 800 . Non-limiting cases for such “other location” provisioning would be in cases, for example, of a number of rescue personnel being deployed to a foreign disaster zone, and having their communication devices (e.g., mobile telephones) being provisioned to communicate using the infrastructure of the foreign location. Such communication may be possible through a secure Internet connection from various provisioning stations 340 across the world to a central provisioning station 377 located at a central location 800 . Many other examples are possible and within the purview of one having ordinary skill in the art.
[0065] The foregoing disclosure of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.
[0066] Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.
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A system and method for automatic provisioning of devices from a host system is disclosed. A computer program operating at the host system detects new devices and performs a series of provisioning operations. These provisioning operations are pre-defined by system administrator and are customizable for each enterprise's unique environment. When the devices are shipped from device manufacturers to enterprise customers, these devices have no enterprise specific information provisioned in them. When the system administrator receives these devices they have to perform several manual and labor intensive operations on the devices. The system and method described automate the provisioning of devices thus eliminating the manual steps that are currently being performed by the users.
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FIELD OF THE INVENTION
[0001] The present invention is related to devices and methods for cooling heat-producing equipment, and more specifically, is related to devices for cooling heat-producing electronic equipment arranged in a row of cabinets.
BACKGROUND OF THE INVENTION
[0002] Referring to FIG. 1 and the Cartesian coordinate system which comprises an x axis 102 , a y axis 104 , and a z axis 106 that are mutually orthogonal, a known air-cooling apparatus 100 , described in US Patent 7 , 085 , 133 , which is incorporated by reference herein in its entirety, includes a row of cabinets 108 , including cabinets 110 , 112 , 114 , 116 arrayed along the x axis 102 . The row of cabinets 108 includes a first cabinet 110 located at the +x end of the row and a last cabinet 116 located at the −x end of the row. An arbitrary number of additional interior cabinets, such as cabinets 112 and 114 shown in FIG. 1 , are positioned between the first cabinet 110 and the last cabinet 116 .
[0003] An intake end-plenum 118 , which includes a sloping wall 120 , abuts the row of cabinets 108 at an upstream face 110 a of the first cabinet 110 to direct cooled air thereto. An exhaust end-plenum 122 , which includes a sloping wall 124 , is adjacent to a downstream face 116 b of the last cabinet 116 to direct exhaust air therefrom. Interposed between each pair of adjacent cabinets is a combined-plenum unit 126 that comprises both an intake plenum 128 and an exhaust plenum 130 . Within each combined-plenum unit 126 , the intake plenum 128 and the exhaust plenum 130 are separated from each other by a sloping wall 132 . The combined plenum units 126 are mounted to the cabinets 110 , 112 , and 114 such that the exhaust plenums 130 thereof abut the cabinets' downstream surfaces 110 b, 112 b, and 114 b respectively, and the intake plenums 128 thereof abut the cabinets' upstream surfaces 112 a, 114 a, and 116 a, respectively. Each cabinet 110 , 112 , 114 , 116 contains heat-producing electronics 134 arranged to allow airflow parallel to the x direction 102 . Therefore, air-moving devices 136 in each cabinet are arranged to induce and encourage an S-shaped airflow 138 . This type of cooling means is used, for example, in IBM°'s Bluegene®/L and Bluegene®/P supercomputers. The abutted row 108 of cabinets 110 , 112 , 114 , 116 and plenums 118 , 122 , 126 stand in a room 140 on a raised floor 142 that is above and substantially parallel to a sub-floor 144 . The raised floor 142 typically comprises a regular two-dimensional array of removable tiles 146 having pitch p in the x 102 and y 104 directions. Cooling air 148 is supplied to an under-floor space 150 between the raised floor 142 and the sub-floor 144 by a plurality of air-conditioning units 152 that are also known in the art.
[0004] Cooling one of the interior cabinets 112 , 114 is accomplished by the S-shaped air-stream 138 passing through a hole 154 in the raised floor, and thereafter through the intake plenum 128 . Drawn by the air-moving devices 136 , the S-shaped air stream 138 travels over the heat-producing electronics 134 , exiting the cabinet through the exhaust plenum 130 . After the S-shaped air-stream 138 exits the exhaust plenum 130 , it is returned to an open top surface 156 of the air conditioning units 152 . Cooling of the first cabinet 110 or last cabinet 116 is similar to that for interior cabinets 114 , except that the air enters the first cabinet 110 through the intake end plenum 118 , and air exits the last cabinet 116 through the exhaust end plenum 122 .
[0005] The known cooling apparatus 100 is deficient because it imposes at least the following several requirements on the room 140 and on the design of the cabinets 110 , 112 , 114 , 116 . First, each cabinet must be fed by an airflow rate V sufficient to keep all the cabinet's internal electronics 134 sufficiently cool. For cabinets that dissipate large quantities of heat, this requirement is often burdensome on the infrastructure of the room 140 because it requires significant investment in air-conditioning units 152 , a large under-floor space 150 , and a disruption of airflow patterns to other, already-existing equipment in the room.
[0006] Second, at the interface between any of the intake plenums 118 , 128 and the abutting cabinets 110 , 112 , 114 , 116 where the air-stream 138 first turns, the flow must be managed carefully, with appropriately designed turning aids, to avoid stagnation regions causing the electronics 134 to reach higher temperatures. This requirement is difficult to achieve in designing the cabinet, and despite best design efforts may be defeated by unusual raised-floor conditions, such as those where the distance between the raised floor 142 and the sub-floor 144 is too small, or where the hole 154 is partially obstructed by either structural members of the raised floor 142 or by equipment such as wires in under-floor space 150 .
[0007] Third, in order to achieve high packing density of cabinets, the combined plenum unit 126 must be narrow. Thus, air must flow vertically through a relatively narrow intake plenum 128 and exhaust plenum 130 . This requirement inevitably incurs pressure loss, leading to reduced flow rate V and increased temperature of the electronics 134 .
[0008] Fourth, holes 154 must be cut in the raised floor 142 underneath each of the intake plenums 118 and 128 . To avoid non-uniform flow leading to hotspots in the cabinet, the holes 154 must not be obstructed by structural members supporting the raised floor. Unobstructed holes are difficult to insure for all installations, because raised-floors are not standard worldwide, for example, the pitch p of the removable tiles 146 may differ from country to country.
[0009] Therefore, a need exists for an improved cooling apparatus and method of cooling a row of cabinets 108 that houses electronic equipment 134 . It would be desirable, without sacrificing airflow through any particular item of the electronics 134 , for the cooling apparatus to operate with the least possible total airflow, thereby minimizing both the cost of air-conditioning equipment 152 and the level of acoustical noise in the room 140 . Further, it would be desirable to minimize constricted air passageways, such as the narrow plenums 128 and 130 , that unduly limit airflow. Moreover, it would be desirable to avoid turns in the airflow path, such as those in the S-shaped airflow path 138 , thereby to eliminate hotspots caused by flow non-uniformities and boundary-layer separation. Finally, it would be desirable to improve cabinet-packing density by minimizing the amount of space devoted exclusively to air handling, such as that occupied by plenums 118 , 122 , and 126 .
SUMMARY OF THE INVENTION
[0010] In an aspect of the invention, a cooling apparatus includes a plurality of heat-producing devices positioned in a plurality of cabinets arranged in a row allowing flow of a first fluid through the heat-producing devices and cabinets. The flow of the first fluid is directed from an upstream end of the row to a downstream end of the row such that an upstream heat-exchanger side abuts a downstream cabinet side the cabinets positioned in spaced relation to each other and defining a space therebetween. A plurality of heat exchangers are positioned at least partially in the spaces between the cabinets and adjacent to the cabinets. Thereby the cabinets and the heat exchangers alternate in the rows, each heat exchanger allowing flow of a second fluid therethrough for cooling the first fluid. At least one fluid-moving device positioned adjacent the heat-producing devices for encouraging the flow of the first fluid through the cabinets' heat-producing devices and through the heat exchangers, thereby encouraging the transfer of heat from the first fluid to the second fluid in the heat exchangers.
[0011] In a related aspect, at least one fluid-moving device is positioned between the heat-producing devices of each cabinet and the heat exchanger immediately downstream of the heat-producing device.
[0012] In a related aspect, the apparatus further includes a first fluid-moving device positioned between the heat-producing device and the heat exchanger, and a second fluid-moving device is positioned between the heat exchanger and the cabinet immediately downstream of the heat exchanger.
[0013] In a related aspect, the apparatus further includes a plurality of first fluid-moving devices positioned between the heat-producing devices and a plurality of heat exchangers, and a plurality of second fluid-moving devices each positioned between the heat exchangers and a front of the plurality of cabinets. In an embodiment of the apparatus, the first fluid may be air. Further, the heat-producing devices may be electronic devices, and further may be heat-producing devices such as computers or computer processors.
[0014] In a related aspect, a plenum is positioned at an upstream side of a first cabinet of the plurality of cabinets for directing incoming ambient air.
[0015] In a related aspect, a first plenum is positioned at an upstream side of a first cabinet of the plurality of cabinets for guiding the direction of incoming ambient air, and a second plenum is positioned at a downstream side of a last cabinet of the plurality of cabinets for guiding the direction of outgoing ambient air.
[0016] In a related aspect, the second fluid is water. In another embodiment of the invention, the heat exchanger includes ingress and egress tubes carrying the second fluid, to remove heat from the first fluid. In another embodiment, the flow of the first fluid is directed in a closed loop.
[0017] In a related aspect, the apparatus further includes a plurality of fluid-moving devices positioned adjacent an upstream side and a downstream side of the heat-producing devices for encouraging flow of the first fluid through the cabinets' heat-producing devices and through the heat exchangers.
[0018] In a related aspect, the apparatus further includes a vertical barrier dividing the cabinets into a front portion and a rear portion, and circulating the first fluid in a closed loop between the front and rear portions. Additionally, the apparatus may include a horizontal barrier dividing the cabinets into an upper portion and a lower portion, and circulating the first fluid in a closed loop between the upper and lower portions.
[0019] In another aspect of the invention, a cooling system in an enclosed room includes a plurality of heat-producing devices positioned in a plurality of cabinets arranged in a row allowing a flow of a first fluid through the heat-producing devices and cabinets. The flow of the first fluid is directed from an upstream end of the row to a downstream end of the row, and the cabinets are positioned in spaced relation to each other and define a space therebetween. A plurality of heat exchangers are positioned at least partially in the spaces between the cabinets and adjacent to the cabinets. Thereby, the cabinets and the heat exchangers alternate in the rows such that an upstream heat-exchanger side abuts a downstream cabinet side, and each heat exchanger allows flow of a second fluid therethrough for cooling the first fluid. At least one fluid-moving device is positioned adjacent the heat-producing devices for encouraging the flow of the first fluid through the cabinets' heat-producing devices and through the heat exchangers, thereby encouraging in each of the heat exchangers a transfer of heat from the first fluid to the second fluid. A first plenum adjacent an upstream side of a first cabinet for directing the flow of the first fluid as it enters the row of cabinets. A last plenum adjacent a downstream side of a last cabinet for directing the flow of the first fluid exiting the row of cabinets.
[0020] In a related aspect, the first fluid is cycled in a closed loop within the enclosed room. In an alternative embodiment, the system further comprises a raised floor in the enclosed room, wherein the raised floor supports the plurality of cabinets, and the first fluid is directed through holes in the raised floor. In a further aspect, each of the heat exchangers provide, at its downstream side, a temperature of the first fluid that is substantially the same as the temperature of the first fluid when entering the upstream side of the first cabinet.
[0021] In another aspect, a method for cooling includes: (a) positioning a plurality of heat-producing devices in a plurality of cabinets arranged in a row; (b) positioning a plurality of heat exchangers in a space between the cabinets and adjacent to the cabinets, thereby alternating the cabinets and the heat exchangers in the row; (c) directing flow of a first fluid through the heat-producing devices, cabinets, and heat exchangers for cooling the first fluid; and (d) positioning a plurality of fluid-moving devices adjacent the heat-producing devices for encouraging flow of the first fluid through the cabinets' heat-producing devices and through the heat exchangers, thereby encouraging heat transfer from the first fluid to a second fluid in each of the heat exchangers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other objects, features and advantages of the present invention will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings, in which:
[0023] FIG. 1 is a front elevational view of a prior art cooling apparatus depicting a row of cabinets with interleaved airflow plenums;
[0024] FIG. 2 is a front elevational view of a cooling apparatus according to an embodiment of the present invention depicting heat exchangers between cabinets in a row;
[0025] FIG. 3 is a front elevational view of an apparatus according to another embodiment of the invention depicting differently arranged plenums;
[0026] FIG. 4 is a front elevational view of an apparatus according to another embodiment of the invention without a plenum on the air-intake end of the row of cabinets;
[0027] FIG. 5 is a front elevational view of an apparatus according to another embodiment of the invention without plenums at either the air-intake end or the air-exhaust end of the row of cabinets;
[0028] FIG. 6 is a front elevational view of an apparatus according to another embodiment of the invention depicting differently arranged plenums;
[0029] FIG. 7 is a front elevational view of an apparatus according to another embodiment of the invention depicting first and second air-moving devices;
[0030] FIG. 8 is a plan view of an apparatus according to another embodiment of the invention depicting a vertical barrier for dividing the cabinets and heat exchangers into front and rear portons; and
[0031] FIG. 9 is a front elevational view of an apparatus according to another embodiment of the invention depicting a horizontal barrier for dividing the cabinets and heat exchangers into upper and lower portions.
DETAILED DESCRIPTION OF THE INVENTION
[0032] Referring to FIG. 2 , an illustrative embodiment of a cooling apparatus 200 according to the present invention uses the same reference numerals for like elements as the prior art apparatus 100 shown in FIG. 1 . However, the apparatus 200 differs from the prior art apparatus 100 in at least two significant ways. First, on the downstream faces of each cabinet 110 , 112 , 114 , 116 , the present invention employs, in contrast to the prior art air plenums 126 , 122 , a series of air-to-water heat exchangers 210 , 212 , 214 , 216 . Second, the present invention uses, in place of the prior art's multiple S-shaped air paths 138 , a single, row-wise airflow path 218 that travels substantially in the −x direction, straight through an entire flow-through row 220 . The flow-through row 220 comprises the cabinets 110 , 112 , 114 , 116 ; the heat exchangers 210 , 212 , 214 , 216 , and optionally an intake plenum and an exhaust plenum such as a bottom-intake plenum 222 , and a bottom-exhaust plenum 224 , respectively.
[0033] The heat exchangers 210 , 212 , 214 , 216 make possible the row-wise airflow path 218 . Referring to the graph 244 of air temperature vs. horizontal coordinate x at the top of FIG. 2 , the heat-producing electronics in cabinet 110 cause the temperature of the air circulating along air path 218 to rise from T 0 to T 1 as it traverses cabinet 110 from the cabinet's upstream face 110 a at x=x 0 to the downstream face 110 b at x=x 1 . The air-to-water heat exchanger 210 is typically a tube-and-fin heat exchanger well known in the art, wherein warm air passes over the heat-exchanger's fins and a cold liquid flows in the heat exchanger's tubes, thereby allowing heat to be transferred from the air to the liquid. The liquid is supplied to each heat exchanger from an external liquid-chilling system via a supply pipe 240 , and is returned to the liquid-chilling system via a return pipe 242 . Therefore, in traversing the heat exchanger 210 from x 1 to x 2 , the temperature of the air, being cooled by the externally chilled liquid, drops from T 1 to T 0 . Thus, the combination of cabinet 110 and heat exchanger 210 is thermally neutral for the air. This air-temperature cycle is repeated for subsequent cabinets and heat exchangers: the air is warmed to temperature T 1 a second time while traversing cabinet 112 in the region x 2 to x 3 , is cooled a second time to temperature T 0 by the heat exchanger 212 in the region x 3 to x 4 , is warmed a third time to temperature T 1 while traversing cabinet 114 in the region x 4 to x 5 , is cooled a third time to temperature T 0 by heat exchanger 214 in the region x 5 to x 6 , is warmed a fourth time to temperature T 1 by cabinet 116 in the region x 6 to x 7 , and is finally cooled a fourth time to temperature T 0 by heat exchanger 216 in the region x 7 to x 8 . Thus, the entire flow-through row 220 is thermally neutral for the air; that is, the air returns to the under-floor space 150 at temperature T 0 , ready to repeat the cycle. Because the air path 218 is closed, the temperatures T 0 and T 1 will automatically float to whatever values cause equilibrium to occur. Thus, it is necessary to choose heat exchangers 210 , 212 , 214 , 216 and air-moving devices 136 such that acceptable temperatures are obtained for the worst-case heat dissipation of electronics 134 . Heat exchanges 210 , 212 , 214 , 216 are described in U.S. patent application Ser. No. 11/939,165, filed Nov. 13, 2007, now abandoned, the disclosure of which is hereby incorporated herein by reference in its entirety. Temperature control of a cooling fluid is also discussed in copending U.S. patent application Ser. No. 12/483,542, filed Jun. 12, 2009, the disclosure of which is hereby incorporated herein by reference in its entirety.
[0034] Again referring to FIG. 2 , the row-wise airflow path 218 is now described in detail. Air enters the first cabinet 110 from the under-floor space 150 , flowing upward through row-intake hole 226 in the raised-floor 142 , and through the perforated metal screen 228 , which may be necessary, depending on the nature of the electronics, to prevent the escape of electromagnetic radiation therefrom into the room 140 . The row-wise airflow path 218 moves upward through the bottom-intake plenum 222 to the first cabinet 110 of the flow-through row 220 . The air-moving devices 136 within the cabinets 110 , 112 , 114 , 116 encourage the row-wise airflow path 218 through each cabinet 110 , 112 , 114 , 116 , and thereby through the entire flow-through row 220 . An intake-end wall 230 of the bottom-intake plenum 222 may, if desired, slant inward toward the top of the first cabinet 110 , inasmuch as upper cross-sections of the intake plenum 222 handle far less airflow than lower cross-sections, and thus require less cross-sectional area. Alternatively, the intake-end wall 230 may be substantially vertical, or removed altogether. In the latter case, the flow-through row 220 draws air from the room 140 rather than from the under-floor space 150 .
[0035] The row-wise airflow path 218 exits the last cabinet 116 of the flow-through row 220 , flowing downward through a perforated-metal exhaust screen 232 whose function is similar to that of the perforated-metal intake screen 228 , downward through a row-exhaust hole 234 in the raised-floor 142 , and thereby into the under-floor space 150 . An exhaust-end wall 236 of the bottom-exhaust end plenum 224 may, if desired, slant outward toward the bottom of the last cabinet 116 , inasmuch as upper cross-sections of the bottom-exhaust plenum 224 handle far less airflow than lower cross-sections, and thus require less cross-sectional area. Alternatively, the exhaust-end wall 230 may be substantially vertical, or removed altogether. In the latter case, the flow-through row 220 exhausts air to the room 140 rather than to the under-floor space 150 .
[0036] Referring to FIG. 3 , another embodiment of the invention is a cooling apparatus 300 that includes a top-exhaust plenum 324 instead of the bottom-exhaust plenum 224 previously shown in FIG. 2 . The top-exhaust plenum 324 is identical to bottom-exhaust plenum 224 except that it is rotated 180 degrees about the x axis, such that top-exhaust plenum 324 is wide at the top, by virtue of a sloping end wall 336 , thereby to accommodate greater airflow at upper cross sections than at lower cross sections In the cooling apparatus 300 , a row-wise airflow 318 behaves as in cooling apparatus 200 , except that in apparatus 300 , the airflow 318 exits the row 220 flowing upward through the top-exhaust end plenum 324 , which has an opening 334 at the top. A perforated metal exhaust screen 332 at the top of top-exhaust plenum 324 serves the same purpose as screen 232 in plenum 224 , as discussed previously. As with the apparatus 200 shown in FIG. 2 , and also pertaining to the embodiments shown in FIGS. 4 , 6 and 7 , depending on the nature of the electronics 134 , it may not be necessary to include the perforated metal screen 332 to prevent the escape of electromagnetic radiation from the flow-through row 220 .
[0037] Referring to FIG. 4 , another alternative embodiment of the invention is a cooling apparatus 400 , where no intake plenum is used. In this embodiment, airflow 418 enters the flow-through row of cabinets 220 directly from the room 140 . The airflow exits the apparatus 400 as in the apparatus 300 shown in FIG. 3 . Pertaining to this embodiment as well as to that shown on FIG. 5 , to prevent the escape of electromagnetic radiation from the flow-through row 220 , it may be necessary, depending on the nature of the electronics 134 , to affix to the upstream surface 110 a of the first cabinet 110 a perforated metal screen 428 , through which air flows immediately prior to entering cabinet 110 .
[0038] Referring to FIG. 5 , another alternative embodiment of the invention is a cooling apparatus 500 where no intake-end plenum or exhaust-end plenum is used. In this embodiment, airflow 518 exhausts from the last cabinet 116 directly to the room 140 . Airflow 518 is otherwise identical to airflow 418 discussed with reference to FIG. 4 . To prevent the escape of electromagnetic radiation from the flow-through row 220 , it may be necessary, depending on the nature of the electronics 134 , to affix to the downstream surface 116 b of the last cabinet 116 a perforated metal screen 532 .
[0039] Referring to FIG. 6 , another alternative embodiment of the invention is cooling apparatus 600 , where a top-intake end plenum 622 and the top-exhaust end plenum 324 are used. The top-intake plenum 622 is identical to the bottom-intake plenum 222 , shown in FIG. 2 , except that it is rotated 180 degrees about the x axis, such that the top-intake plenum 622 is wide at the top, by virtue of a sloping end wall 630 , thereby to accommodate greater airflow at upper cross sections than at lower cross sections. In this embodiment, an airflow 618 enters the flow-through row 220 downward through the top-intake end plenum 622 and exits the flow-through row 220 upward through the top-exhaust end plenum 324 .
[0040] Referring to FIG. 7 , another embodiment of the invention is a cooling apparatus 700 , which is similar to the apparatus 200 shown in FIG. 2 . However, in the apparatus 700 shown in FIG. 7 , the heat-exchanger 210 is replaced by a heat-exchanger assembly 710 that comprises, in addition to the heat exchanger 210 , an array of air-moving devices 760 , such as axial-flow fans. Likewise, the heat exchangers 212 , 214 , and 216 shown in FIG. 2 are replaced, in apparatus 700 , by heat-exchanger assemblies 712 , 714 , 716 respectively, which comprise, in addition to heat exchangers 212 , 214 , and 216 respectively, air-moving devices 762 , 764 , and 766 respectively. Thus, the cooling apparatus 700 includes air-moving devices 760 , 762 , 764 , 766 that supplement the air-moving devices 136 within the cabinets 110 , 112 , 114 , 116 . Alternatively, depending, for example, on the cost and pressure-rise requirements of the cooling system and on the space required by the electronics, the air-moving devices 760 , 762 , 764 , 766 may replace the air-moving devices 136 contained within the cabinets 110 , 112 , 114 , 116 .
[0041] The heat-exchanger assemblies 710 , 712 , 714 , 716 , although described above for use with the airflow arrangement of the cooling apparatus 200 shown in FIG. 2 , may also be used with any of the other airflow arrangements, as shown in cooling apparatuses 300 , 400 , 500 , and 600 of FIGS. 3-6 , respectively.
[0042] Referring to FIG. 8 , another embodiment of the invention is a cooling apparatus 800 , wherein each of the cabinets 110 , 112 , 114 , 116 is internally divided into a front portion 802 and a rear portion 804 . Note that FIG. 8 is a plan view, as specified by the orientation of the x, y, and z axes 102 , 104 , 106 respectively, whereas FIGS. 1-7 and 9 are front elevational views. In each cabinet, the portions 802 , 804 are separated from each other by a vertical cabinet barrier 806 that substantially prevents air flow across it. The barrier 806 lies substantially parallel to an xz plane spanned by the x and z axes. Likewise, each of the heat-exchangers 210 , 212 , 214 , 216 comprises, in this embodiment, a vertical heat-exchanger barrier 808 that substantially prevents airflow across it. The cabinet barriers 806 and the heat-exchanger barriers 808 are substantially co-planar. A first closed-end plenum 810 is abutted to the upstream face 110 a of the first cabinet 110 , and a second closed-end plenum 812 is abutted to a downstream face 216 b of the heat exchanger 216 . Front air-moving devices 814 in the front portion 802 of the cabinets 110 , 112 , 114 , 116 are configured to drive a closed-horizontal-loop air-stream 818 in the −x direction, while rear air-moving devices 816 in the rear portion 804 of the cabinets 110 , 112 , 114 , 116 are configured to drive the closed-horizontal-loop air stream 818 in the +x direction, such that the air stream 818 circulates in a closed loop about the vertical z axis 106 . That is, the closed-horizontal-loop air-stream 818 flows toward +x in the rear portion 804 of the cabinets 100 , 112 , 114 , 116 and heat exchangers 210 , 212 , 214 , 216 , then toward −y in the first closed-end plenum 810 , then toward −x in the front portion 802 of the cabinets and heat exchangers, and finally toward +y in the second closed-end plenum 812 , thus completing a closed loop. This closed-loop embodiment is advantageous because it imposes no air-handling burden on the room 140 , and because it provides very quiet operation of the air moving devices 814 , 816 , particularly when the cabinets 110 , 112 , 114 , 116 , heat-exchanger assemblies 210 , 212 , 214 , 216 , and closed-end plenums 810 , 812 are acoustically insulated, because people in the room 140 are shielded from the noise of air movers and flowing air.
[0043] Again referring to the apparatus 800 shown in FIG. 8 , it should be noted that the closed-horizontal-loop air stream 818 , at its +x end, traverses two sets of heat-producing electronics 134 , in the rear portion 804 of the first cabinet 110 and in the front portion 802 of the first cabinet 110 , without any intervening heat exchanger to cool the air. If this causes the air to become unacceptably warm in the front portion 802 of cabinet 110 , so as to compromise cooling of the electronics 134 therein, then an additional heat exchanger identical to 210 may be abutted to the +x surface of the first cabinet 110 .
[0044] Referring to FIG. 9 , another embodiment of the invention is a cooling apparatus 900 , wherein each of the cabinets 110 , 112 , 114 , 116 is internally divided into a lower portion 902 and an upper portion 904 . In each cabinet, the portions 902 , 904 are separated from each other by a horizontal cabinet barrier 906 that substantially prevents air flow across it. Barrier 906 lies substantially parallel to an xy plane spanned by the x and y axes Likewise, each of the heat-exchangers 210 , 212 , 214 , 216 comprises, in this embodiment, a horizontal heat-exchanger barrier 908 that substantially prevents air flow across it. The cabinet barriers 906 and the heat-exchanger barriers 908 are substantially co-planar. A first closed-end plenum 910 is abutted to the upstream face 110 a of the first cabinet 110 , and a second closed-end plenum 912 is abutted to a downstream face 216 b of the heat exchanger 216 . Lower air-moving devices 914 in the lower portion 902 of the cabinets 110 , 112 , 114 , 116 are configured to drive a closed-vertical-loop air-stream 918 in the −x direction, while upper air-moving devices 916 in the upper portion 904 of the cabinets 110 , 112 , 114 , 116 are configured to drive the closed-vertical-loop air stream 918 in the +x direction, such that the air stream 918 circulates in a closed loop about the horizontal y axis 104 . More specifically, the closed-horizontal-loop air-stream 918 flows toward +x in the upper portion 904 of the cabinets 100 , 112 , 114 , 116 and heat exchangers 210 , 212 , 214 , 216 , then toward −z in the first closed-end plenum 810 , then toward −x in the lower portion 902 of the cabinets and heat exchangers, and finally toward +y in the second closed-end plenum 812 , thus completing a closed loop. This closed-loop embodiment, shown in FIG. 9 , is advantageous for the same acoustic reason described earlier in connection with apparatus 800 shown in FIG. 8 .
[0045] Again referring to the apparatus 900 shown in FIG. 9 , it should be noted that the closed-horizontal-loop air stream 918 , at its +x end, traverses two sets of heat-producing electronics 134 , in the upper portion 904 of the first cabinet 110 and in the lower portion 902 of the first cabinet 110 , without any intervening heat exchanger to cool the air. If this causes the air to become unacceptably warm in the lower portion 902 of cabinet 110 so as to compromise cooling of the electronics 134 therein, then an additional heat exchanger identical to 210 may be abutted to the +x surface of the first cabinet 110 .
[0046] Additionally, other embodiments and variations are possible keeping with the spirit and scope of the invention, for example, although the embodiments presented herein have included “air-to-water heat exchangers”, the heat exchangers may use other fluids. In another example, the water supply and return pipes 240 , 242 may enter the heat-exchangers 210 , 212 , 214 , 216 from the top rather than from the bottom.
[0047] All the embodiments of the current invention, including those represented as cooling apparatuses 200 , 300 , 400 , 500 , 600 , 700 , 800 , and 900 , shown in FIGS. 2-9 , respectively, have a number of significant advantages over the prior-art apparatus 100 shown in FIG. 1 , including those discussed hereinafter. A first advantage is that the total airflow required in the room 140 , and the associated acoustical noise, are greatly reduced by the invention vis-à-vis the prior art, leading to greater acoustical comfort for humans in the room 140 , and to less disruption of airflow if the room houses an existing installation of other equipment. Quantitatively, if volumetric flow rate V of air is required to cool each cabinet, and there are N cabinets in a row, then the prior art requires a total flow rate of NV per row, whereas the present invention which requires only V per row. This is a factor of N improvement that allows installation of such cabinets in buildings unable to support large amounts of airflow, and also reduces the total amount of airflow noise.
[0048] Second, many fewer air-conditioning units 152 are required in the room 140 by the invention than by the prior art, leading to lower capital investment in air-conditioning units 152 and lower energy cost to drive air-moving devices therein. According to the invention, the heat load of electronics 134 is transferred from the air locally to water flowing in pipes 240 , 242 of heat exchangers 210 , 212 , 214 , 216 . Therefore, the flow-through row 220 puts no thermal load on the room 140 , and thus requires only minimal air-conditioning for general dehumidification, and ancillary heat loads. In contrast, the prior-art row 108 dissipates all its heat load to the room, thus requiring, if the number of cabinets and the power dissipation therein is large, a great number of air-conditioning units 152 .
[0049] Third, the prior-art's narrow airflow plenums 126 , shown in FIG. 1 , are eliminated. Such narrow plenums are required by the prior art to achieve compact packaging along the flow-through row 220 , and to insure that the holes 154 in the raised floor 142 match the periodicity p of the raised-floor tiles 146 . However, air velocity is high in the narrow airflow plenums 126 , typically much larger than in the cabinet itself, because the cross-sectional area normal to the airstream is much smaller in the plenum than in the cabinet. Thus pressure drop in the airflow plenums 126 is large, and airflow rate through the prior-art electronics 134 is thereby restricted, increasing the temperature therein and reducing the lifetime and performance thereof. In the invention, this source of pressure drop is eliminated. Some pressure loss occurs in the invention's heat exchangers 210 , 212 , 214 , 216 , but because the cross-sectional area of the heat exchanger is large, air velocity is low, and therefore pressure drop is relatively small.
[0050] Fourth, flow non-uniformities that occur in the prior art are eliminated. Specifically, the narrowness of the prior art's airflow plenums 126 cause flow separation at locations near the upstream faces 110 a, 112 a, 114 a, 116 a of the cabinets wherever the airflow cannot negotiate a tight turn around a sharp edge. In the wake of such separation is a stagnation region of very-low-velocity airflow that causes very high temperatures of the electronics 134 therein. The tendency to separate may be minimized by widening the prior-art combined plenums 126 , but this is highly undesirable in the prior art, because of the desire to achieve a compact footprint of the row 108 of cabinets and plenums, and because of the aforementioned requirement to match the periodicity of the holes 154 with the pitch p of the removable tiles 146 . In contrast, embodiments 400 and 500 of the current invention require no air turn upstream of any electronics 134 , so the problem of flow separation is completely eliminated. All other embodiments require just one air turn per row 220 , upstream of the first cabinet 110 . Because the invention has only one intake plenum per row 220 rather than one intake plenum per cabinet as in the prior art, beneficial widening of the intake plenum, mentioned above, has, for the invention, much less impact on the footprint of a row 220 than a similar widening would have for the prior-art row 108 . That is, widening each of the prior-art's inlet plenums ( 118 and 128 ) by an amount d widens the prior-art cabinet row 108 by an amount Nd, where N is the number of cabinets per row. In contrast, widening the invention's intake end plenum ( 222 or 622 , depending on the embodiment) by the same amount d widens the invention's flow-through row 220 merely by d, a factor-of-N improvement over the prior art.
[0051] Fifth, the prior art's need to turn the air twice in each cabinet 110 , 112 , 114 , 116 is eliminated by the invention. By replacing the prior-art's S-shaped air-streams 138 , with the single, row-wise airflow path 218 most or all of the air turns are eliminated. Specifically, instead of two 90-degree turns per cabinet in the prior-art apparatus 100 , there are only four turns per row in apparatuses 200 , 700 , 800 , and 900 ; only two turns per row in apparatuses 300 and 600 ; only one turn per row in apparatus 400 ; and zero turns per row in apparatus 500 . Fewer turns is desirable because turning air incurs pressure drop and thereby reduces airflow, raising the temperature, shortening the life and compromising the performance of the electronics 134 .
[0052] Sixth, compared to the prior art, the invention provides additional space for air-moving devices. As shown by apparatus 700 in FIG. 7 , an air-to-water heat exchanger specified by this invention, such as 210 , need not occupy the entire space between the adjacent cabinets 110 and 112 ; instead, some of this space may be occupied by the array of air-moving devices 760 , which either supplement or replace the air-moving devices 136 internal to cabinet 110 . If air-moving devices 760 , 762 , 764 , 766 supplement air-moving devices 136 , then the pressure rise of the system (and hence the air velocity) is greatly increased, a benefit that may be used either to reduce the temperature of the electronics, or to cool more electronics or more powerful electronics. If, instead, the air-moving devices 760 , 762 , 764 , 766 replace air-moving devices 136 , then the space vacated by 136 may beneficially be used to house more electronics 134 in cabinet 110 .
[0053] Seventh, the periodic, large airflow holes 154 in the raised floor 142 of the prior-art apparatus 100 are eliminated by this invention, thereby reducing the system's dependence on the pitch p of removable tiles 146 of the raised floor 142 . For example, in apparatus 200 shown in FIG. 2 , pitch C of cabinets along a row, defined as C η x 8 -x 6 η x 6 -x 4 η x 4 -x 2 η x 2 -x 0 , is substantially unconstrained by the pitch p of the raised-floor tiles 95 , because the only holes therein are small holes for the supply and return pipes 240 and 242 . However, in the prior art, the holes 154 are large, and thus it is more important that the cabinet pitch C and the tile pitch p be more closely synchronized, to avoid interfering with struts that support the raised floor 142 . Toward this end, in the prior art, C and p are preferably related by a simple proportion such as mC=np where m and n are small integer such as (m, n)=(1,2) or (m, n)=(2,3). No such restriction applies to the invention.
[0054] Eighth, redundancy of the air-moving devices 136 is improved by the invention vis-à-vis the prior art. Specifically, along a flow-through row of cabinets 220 , air-moving devices 136 sharing a common streamline back each other up, such that failure of a single air-moving device 136 is much less significant than for the prior-art's separate, S-shaped airstreams 138 , wherein failure of an air-moving device can cause the temperature of nearby electronics to rise. For apparatus 700 , similar redundancy is achieved for the supplementary, or alternative, series of air movers 762 , 764 , 766 , 768 .
[0055] Ninth, the invention improves cabinet-packing density vis-à-vis the prior art, thereby saving valuable floor space and also improving electrical-signaling performance between cabinets by allowing shorter cables. Specifically, the stream-wise (x) dimension of one of the heat exchangers assemblies 210 , 212 , 214 , 216 is typically far smaller than the x dimension of one of the prior art's combined plenum units 126 , because the heat-exchanger's x dimension need only be large enough to accommodate tubes and fins to transfer heat from air to water, whereas the combined plenum unit's x dimension must be large enough to accommodate, through the intake plenum 128 and the exhaust plenum 130 , the large volumetric flow-rate of air, denoted V, that is needed to cool electronics 134 . For example, in the IBM® BlueGene/P® supercomputer, which comprises electronics 134 in each cabinet dissipating as much as 40 kW, and whose (x, y, z) cabinet dimensions are (70 cm, 89 cm, 180 cm), the x dimension of one of the heat exchangers 210 , 212 , 214 , 216 need only be 10 cm, whereas the x dimension of the combined plenum unit 126 must be 52 cm in order to accommodate V=2.35 m3/s (5000 CFM). Thus, cooling BlueGene/P according to the current invention saves about 42 cm of width per cabinet, which is about 47% of the width of the cabinet itself.
[0056] Thereby, the present invention clearly is advantageous for at least the reasons above in use with a supercomputer requiring rows of cabinets such as IBM®'s BLUEGENE®, by the single stream of air flowing through a row of cabinets, passing alternately through cabinets and heat exchangers, instead of flowing air separately through each cabinet.
[0057] While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that changes in forms and details may be made without departing from the spirit and scope of the present application. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated herein, but falls within the scope of the appended claims.
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A cooling apparatus and method including a plurality of heat-producing devices positioned in a plurality of cabinets arranged in a row that allows flow of a first fluid through the heat-producing devices and cabinets where the flow is directed from an upstream end of the row to a downstream end of the row. The cabinets have a space therebetween wherein a heat exchanger is positioned between and adjacent to the cabinets, thereby the cabinets and heat exchangers alternate in the row. Each heat exchanger allows flow of a second fluid therethrough for cooling the first fluid. A fluid-moving device is positioned adjacent the heat-producing devices for encouraging flow of the first fluid through the cabinets' heat-producing devices and through the heat exchangers, thereby encouraging heat transfer in each of the heat exchangers from the first fluid to the second fluid.
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BACKGROUND OF THE INVENTION
1. Field of the invention
This invention relates to a pressure control circuit for use in an automatic transmission of a vehicle, and more particularly to a pressure control circuit of the type described, which is adapted for use in a pressure regulating circuit for the output hydraulic pressure which operates a frictional engaging means such as the speed change gear of an automatic transmission, a clutch, a brake and the like.
2. Description of the prior art
In general, when the change-over from a forward driving mode to a backward driving mode or vice versa in a speed change gear is accomplished by means of hydraulic control, abrupt engagement of a frictional engaging means will lead to the occurrence of a shock, whereby not only a driver or passengers undergo uncomfortable feeling but also parts of a speed change gear or other associated parts will receive impact, resulting in the failure to provide an intended service life therefor. Hitherto, many attempts have been suggested to remedy a shock which will be experienced upon engagement of the aforesaid engaging means. The common practice adopted for such prior art mechanism is that (i) a discharge pressure from an oil pump is adjusted by means of a pressure regulating valve to a given level which accommodates the maximum load running operation of a motor vehicle, and (ii) there are provided an orifice in the oil line from the pressure regulating valve to an actuator of a clutch or a brake for suppressing or smoothing a pressure rise at a clutch or brake, upon actuation of the actuator, and a hydraulic pressure augmenting or increasing means such as an accumulator, a modulator valve or the like.
However, such attempts only meet partial success in solving this sort of problem, because the hydraulic pressure, which has been regulated by means of the aforesaid pressure regulating valve, i.e., the line pressure still remains high, as compared with the pressure which would be required for a clutch or brake upon their engagement in the normal running of a vehicle, so that there still remains a shock at the time of engagement. Thus, the relief of this sort of shock from a driver or passengers dictates the use of a hydraulic pressure augmenting means having a complicated construction, and hence an increase in size.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a pressure control circuit for use in an automatic transmission of a vehicle which will maintain the hydraulic pressure to be supplied to the frictional engaging means to a value commensurate to an engaging force required by the aforesaid frictional engaging means, until the aforesaid frictional engaging means has completed the intended engagement or for an additional certain period of time thereafter, and which is adapted to urge a pressure control valve with a valve spool shifting in an accumulator, after completion of the aforesaid engagement, to thereby increase the pressure to be supplied to the frictional engaging means.
It is a further object of the present invention to provide a pressure control circuit for an automatic transmission of a vehicle which relieves a shock arising from the engagement of a frictional engaging means and also lessens the shock to a level commensurate with the decrease or increase in the engaging force of the frictional engaging means by using a pressure of a level in response to an output of an engine.
These and other objects and features of the present invention are readily attained in a pressure control circuit for use in an automatic transmission of a vehicle which comprises: a hydraulic pressure source; a pressure regulating valve for regulating a hydraulic pressure from said hydraulic pressure source, said pressure regulating valve provided with a valve spool having portions of different cross sectional areas, a spring for urging said valve spool in one direction to increase the hydraulic pressure, a discharge port, an input port and an output port, said valve spool being adapted to be shifted in an opposite direction against the said spring acting in said one direction, whereby said discharge port may be opened or closed, and said input port being communicated with said hydraulc pressure source at all times; an actuator in communication with said output port of said pressure regulating valve and adapted to be actuated due to the hydraulic pressure regulated by said pressure regulating valve; a first line means for communicating said hydraulic pressure source with said actuator; and accumulator provided within said pressure regulating valve in said opposite direction with respect to said valve spool, and having a piston, a spring for urging said piston in said opposite direction and a hydraulic pressure chamber is positioned on the opposite side of said spring with respect to said piston; a second line means branched from said first line means and communicating with said hydraulic pressure chamber in said accumulator; and an orifice means located between the branching point of said second line means and said hydraulic pressure source; whereby during the time which the hydraulic pressure in said second line means is maintained to below a given value, said piston in said accumulator is biased against the action of said spring in said one direction, and when said hydraulic pressure in said second line means reaches said given value, said piston in said accumulator will abut said valve spool in said pressure regulating valve to thereby mechanically impart an urging force to said piston in said one direction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pressure control circuit for use in an automatic transmission of a vehicle, showing one embodiment of the present invention;
FIG. 2 shows another embodiment of the present invention, the line shown by a broken line representing a further embodiment of the present invention; and
FIG. 3 is a plot showing the pressure to be supplied to a frictional engaging means embodying the present invention, in which the solid lines represent the embodiments of FIG. 1 and FIG. 2, while the broken line represents the further embodiment of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is shown a hydraulic circuit diaphragm, in which a control circuit according to the present invention is applied to a hydraulic circuit of a single forward-speed-ratio and single-reverse-speed-ratio-torque converter, speed change gear for an industrial vehicle. Shown at 1 is an oil pump adapted to introduce oil through an oil line 2 from an oil reservoir 3 and to discharge the oil under pressure into a discharge oil line 4. Shown at 5 is a pressure regulating valve having an elongated valve body 6, a valve spool 7 slidably fitted in sealed relationship within a valve bore 6a in the valve body 6, and a spring seat member 9 adapted to transmit a tension of a spring 8 to the valve spool 7. Provided in the rear of and in series to the spring 8 of the pressure regulating valve 5 is an accumulator piston 10, which is urged under the action of a spring 11 to the right as viewed in FIG. 1. An orifice 13 is provided midway in the high pressure oil line 12 leading from the pressure regulating valve 5. The branch oil line 17, leads from a position close to the orifice 13 to the righthand end closure for the accumulator piston 10 so as to cause the hydraulic pressure to act on the righthand end face of the piston 10. The main line 12 connects to the manual shift valve 14 controlling the forward clutch 15 and the reverse clutch 16 through the line 31. A projecting portion 10a extends from the center of the accumulator piston 10 toward the pressure regulating valve 5 and is adapted to urge a seat 18 of the spring 8, when the piston 10 is displaced by high pressure oil from the line 17. The valve body 6 of the pressure regulating valve 5 is provided with a number of ports namely the inlet port 6b, discharge ports 6c, 6d, the discharge ports 6e, 6f, and the inlet port 6g, l a valve chamber 6h and an accumulator chamber 6j, with the port 6b in communication with the discharge oil line 4. The ports 6e and 6f serve to discharge oil line 4. The ports 6e and 6f serve to discharge hydraulic fluid therethrough back to the oil reservoir 3. The port 6d is provided with an orifice 19, and is communicated by way of an oil line 20 with a torque converter 21. The torque converter 21 is connected by way of an oil line 22 to a pressure regulating valve 23 for regulating the pressure at the exit of the torque converter. The port 6c is communicated with the inlet port 24b in the manual shifting valve 14 by way of the oil line 12 having the orifice 13 therein. The manual shift valve 14 has a valve body 24 having a valve bore 24a and a valve member 25. The valve body 24 has therein the ports 24b, 24d, 24e, 24f, 24g, and 24h adapted to communicate with the valve bore 24a. The valve 25 has large diameter portions 26a, 26b, 26c and which are slidably fitted in the valve bore 24a in sealed relationship, and small diameter portions 26d and, 26e. The ports 24e and 24h are discharge ports leading to the oil reservoir 3, while the port 24c is communicated by way of an oil line 27 with the port 24d, the oil line 27 being communicated by way of an oil line 28 with a supply chamber 29 for the forward speed clutch 15. Furthermore, the port 24f is in communication with the port 24g by way of an oil line 30, which in turn is connected by way of an oil line 31 to a reverse speed clutch 16. The port designated 32 is a piston and shown at 33 is a return spring for the piston 32 operating within the supply chamber 29 of the forward clutch 15 in a known manner.
Description will now be made of the operation by referring to the embodiment shown in FIG. 1. The valve member 25 of the manual shift valve 14 is in its neutral position and thus the oil discharged from the oil pump 1 is discharged through oil lines 4, 27 and, 30 back into the oil reservoir 3. In this respect, the hydraulic pressure will be increased upstream of the orifice 13 in the oil line 12 due to the action of the orifice 13. However, the hydraulic pressure thus increased is so low that even if this hydraulic pressure is introduced into a chamber 6h through an orifice 7c provided in a large diameter portion 7aof the valve spool 7, it will not displace the valve spool 7 to the right by overcoming the tension of the spring 8, and hence the valve spool 7 will remain in its neutral position closing the discharge port 6e. As a result, the hydraulic oil in the line 4 will be introduced to the torque converter 21 via port 6d, orifice 19 and oil line 20, whereby the hydraulic oil required for the torque converter 21 will be supplied thereto. Under such a condition, if the valve 25 in the manual shift valve 14 is shifted to the left as viewed in the drawing, the large diameter portions 26a and 26b of the valve 25 will close the ports 24d and 24f, so that the hydraulic oil in the oil line 12 will be supplied to the forward speed clutch 15. This will increase the hydraulic pressure in the oil line 12 and the hydraulic pressure in the chamber 6g, thereby biasing the valve spool 7 in the pressure regulating valve 5 to the right by overcoming the action of the spring 8, such that the hydraulic pressure will be regulated to a pressure commensurate to the urging force of the spring 8, when the large diameter portion 7b of the valve spool 7 almost opens the discharge port 6e. The hydraulic pressure thus regulated is so adjusted beforehand to a level sufficient for the initial engagement of the clutches 15 and 16. As long as the piston 32 of the clutch 15 is being biased so as to cause the engagement in the clutch 15, the hydraulic pressure in the oil line 28 will be maintained to a level commensurate to a spring force of the return spring 33 of the piston 32. When the accumulator piston 10 is biased to an extent until completion of the clutch, the accumulator piston 10 will urge the spring seat 18 so as to increase a force of the spring 8, thereby increasing a control pressure for the pressure regulating valve 5. The description given thus far refers to the case where the manual shift valve 14 is displaced to the forward position. However, the same description will apply to the case where the manual shift valve is displaced to the backward position.
FIG. 2 refers to another embodiment of the present invention. Shown at 34 is a first regulator valve, in which the pressure oil from an oil pump is received in a port 35 and a chamber 43 to thereby regulate the pressure to a given higher level, while a manual shift valve 38 is connected to an oil line for suppling a high-pressure-line which has been regulated by a first regulator valve 34 or the low-pressure-line pressure which has been regulated by a second regulator valve 36, whereby either one of the pressures in the aforesaid both high and low pressure lines is selectively supplied to a frictional engaging means, i.e., a clutch 39, brake 40 or 41 to operate same, thus causing the speed change gear to establish a different driving ratio. The first regulator valve 34 has a valve member 42 provided with two lands 42a and 42b of the same diameter, and chambers 43 and 44 adapted to apply the hydraulic pressure to the lands 42a and 42b, with a line pressure intake port 45 in the first regulator valve 34 communicating through the oil line 37 with the port 47 in the regulator cut-off valve 46. Shown at 48 is an orifice which is adapted to absorb the surge in the hydraulic oil to be supplied to the chamber 43 and prevents the vibration of the valve 42, while the orifice 49 serves to regulate the flow rate of the circulating oil to the torque converter. The regulator cut-off valve 46 has a valve member 50 having two lands 50a and 50b, and a spring 51 acting downwardly all the time, whereby the regulator cut-off valve 46 is normally in the position as shown in FIG. 2, due to the action of a spring 51. At this time, the port 47 in communication with the oil line 37 is closed by means of the land 50b. On the other hand, the valve member 50 will be displaced upwardly, when the governor pressure exerting to the interior of the chamber 52 is beyond a predetermined value and thus overcomes a downward force of the spring 51, thereby bringing the port 47 in communication with an oil line 55 connecting with the port 53 and chamber 54 in the second regulator valve 36 through the cavity confined between the lands 50a and 50b. The second regulator valve 36 has a valve member 56 having two lands 56a and 56b, and a spring 57 adapted to act downwardly, whereby the hydraulic pressure introduced through the port 53 into the chamber 58 causes the land 56b to be biased to open the discharge port 60 at the same pressure as the hydraulic pressure which has been introduced into the chamber 54 through the orifice for preventing vibration, thereby providing a line pressure regulated to below the high-pressure-line pressure which is regulated by means of the first regulator valve 34. Subsequently, when in `N` position, the manual shift valve 38 blocks the oil line 37, with the oil lines 61, 62 and 63 in communication with the discharge ports, while the clutch 39 and brakes 40 and 41 are left disengaged, presenting a neutral condition. When the manual shift valve 38 is brought to the `D` position, then the oil line 37 will be communicated with the oil lines 61 and 62, and on the other hand, when in the `L` position, the oil line 37 will be communicated only with the oil line 62. Furthermore, when in the `R` position, the oil line 37 will be communicated only with the oil line 63 which is in communication with an engaging chamber in the second brake 41. On the other hand, the oil line 61 is communicated with a supply port in a throttle valve 64 and a shift valve 65. The throttle valve 64 regulates the throttle pressure commensurate to the opening position of an engine throttle valve (not shown), thereby supplying the aforesaid throttle pressure to a chamber 70 in the shift valve 65 and to a chamber 44 in the first regulator valve 34. When the governor pressure in the chamber 70 in the shift valve 65 exceeds a predetermined pressure, then the pressure oil in the oil line 61 will be supplied by way of the oil line 66 to a pressure control valve spool 67 and then the hydraulic pressure is exerted by way of the oil line 68 to the righthand face of the accumulator piston 10 as well as to a supply chamber of the clutch 39 and a release chamber of the brake 40. Furthermore, an orifice 69 is provided in the rear of the pressure control valve spool 67, with an accumulator piston 10 interposed between the orifice 69 and the clutch 39, so that when the piston 10 is biased to a sufficient extent, the piston 10 will urge the pressure control valve spool 67 so as to stop its controlling action as well as to increase the clutch pressure, while causing the throttle pressure to act on the side of the spring 11 of the accumulator piston 10 as well as on the side of the spring 84 of the pressure control valve spool 67 to thereby bring the clutch pressure in responsing relation to the throttle pressure. Confined within a chamber 40 in the shift valve 65 is a spring 72 adapted to urge a valve 71 to the right, while there is provided a chamber 73, into which is supplied a governor pressure, on the side counteracting a force of the spring 72 and a force created by the throttle pressure, with the chamber 73 in communicaton with the oil line 74. Designated 75 is a governor valve communicating with the oil lines 62 and 74.
Now, description will be made of the operation by referring to the embodiment shown in FIG. 2, which represents a neutral position. The high-pressure-line pressure which has been regulated to a given high pressure by means of the first regulator valve 34 is supplied to the oil line 37, while the aforesaid high pressure is blocked by the manual shift valve 38 and thus leads to no other line, so that the clutch 39 and brakes 40 and 41 are not maintained in an engaged condition. On the other hand, the line pressure in the oil line 37 leading to the regulator cut-off valve 46 is blocked by the land 50b in the valve 50, so that the high pressure regulated by the first regulator valve 34 will be applied to the oil line 37. If the manual shift valve 38 is biased on the `D` position from this condition, then the line pressure in the oil line 37 will be introduced into the oil lines 61 and 62.
The high-pressure-line pressure introduced into the oil line 62 will be supplied to a supply chamber in the first brake 40 to thereby bring the brake into engagement, as well as to the governor valve 75. The high-pressure-line pressure which has been introduced into the oil line 61 at this time is communicated with supply ports in the shift valve 65 and throttle valve 64. As a result, the throttle valve 64 will produce a pressure in response to the opening position of the throttle valve of an engine, and then the throttle pressure thus produced will be supplied to a chamber 70 so as to cause down-shifting of the valve 65. Supplied to a chamber 73 which attends upon the upward-shifting and is positioned on the opposite side to the chamber 70 in the shift valve 65 is a governor pressure from a governor valve 75, so that the operation of the shift valve 65 may be controlled depending on the comparison of the governor pressure with the throttle pressure. On the other hand, the throttle pressure which has been introduced into a pressure augmenting chamber 44 in the first regulator valve 34 serves to regulate the high-pressure-line pressure regulated by the first regulator valve 34 to a higher level commensurate to the opening position of the throttle valve of a engine at that time.
The throttle pressure which has been introduced into the chamber 70 in the shift valve 65 will bias the valve 71 to the right as viewed on the drawing against the governor pressure in the chamber 73, in cooperation with the spring 72. As a result, until the governor pressure is increased to a sufficient pressure, the valve 71 in the shift valve 65 will continue to block the communication with the oil lines 61 and 62. As a result, when the speed of a vehicle is low and the governor pressure is not increased to a desired level, the aforeward low speed mode will result, when the valve 38 is in the `D` position. Under such a condition, if the speed of a vehicle is increased and thus the governor pressure in the chamber 73 in the shift valve 65 overcomes the action of the spring 72 to thereby bias the valve 71 to the left, then the line pressure in the oil line 61 will be introduced via oil line 66, orifice 69 and oil line 68 to the righthand face of the accumulator piston 10 as well as to the engaging chamber in the clutch 8 and to the release chamber in the brake 40. It follows that the pressure rise in the release chamber will be controlled by means of the operation of the pressure control valve spool 67 and the accumulator piston 10, thus bringing the clutch 8 in to smooth engagement. Upon completion of engagement of the clutch 8, the projecting portion 10a of the accumulator piston 10 will directly urge the pressure control valve spool 67 through an opening 10b provided in the wall 10c defining two chambers on the opposite sides thereof to thereby stop its controlling action and increase the clutch pressure, while it will release the first brake to provide a forward high speed mode.
Furthermore, in case the throttle pressure is introduced from the outlet 83 in the shift valve 65 through the line 82 into the inlet 81 in the pressure regulating valve, the pressure rise in the engaging chamber in the clutch 8 as well as in the release chamber in the brake 40 is controlled to a pressure commensurate to the throttle pressure by means of the pressure control valve spool 67, thus producing a torque in response to an output torque of an engine, with the result of a smooth engagement of the clutch 8. Then, upon completion of engagement of the clutch 8, the projecting portion 10a of the accumulator piston 10 will directly urge the control valve spool 67. This will stop the controlling action of the valve spool 67, lead the increased pressure to the clutch to bring the clutch 8 in engagement and release the brake 40, thus completing the shifting to the forward high speed mode.
As is apparent from the foregoing description, according to the present invention, the supply pressure until the engagement of the frictional engaging means will be maintained to a low pressure, while in case the throttle pressure is introduced, it is maintained to a level commensurate to the throttle pressure. Upon completion of engagement, an augmented pressure is applied to the pressure control valve according to the stroke of the accumulator to thereby increase the supply pressure, while increasing the capacity of the engaging means, thus facilitating the design of an orifice accumulator. According to one aspect of the present invention, an accumulator and a valve body are connected to the pressure control valve on the side to increase the pressure in the aforesaid pressure control valve, so that positive operation will result with the additional advantages of less sliding resistance and the like, due to the direct urging of the piston.
The invention has been described in detail with particular reference to the preferred embodiment and alternative embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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A pressure control circuit for use in connection with an automatic transmission of a vehicle is disclosed which comprises a pressure regulating valve for regulating a hydraulic pressure discharged from a pressure source and for actuating frictional engaging means, said pressure regulating valve including an accumulator, a valve spool and a spring urging said valve spool in one direction, said accumulator including a hydraulic chamber, into which is supplied the hydraulic pressure which will mechanically impart an additional force to said spring at a given value of the hydraulic pressure.
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part (CIP) application based upon the International Application PCT/JP2008/002277, the International Application Date of which is Aug. 22, 2008, and is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-217885, filed in the Japanese Patent Office on Aug. 24, 2007, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a radiation monitor that is provided in radiation utilization facilities, facilities requiring radiation protection, or the like so as to monitor radiation and a method for checking operation of the same and, more particularly, to a radiation monitor provided with an operation check function using an optical pulse and a method for checking operation of the same.
[0003] As a commonly-used radiation monitor, there is known a semiconductor type radiation monitor using a detection element obtained by giving sensitivity with respect to radiation to the p-n junction of a diode in a sensor section. The semiconductor type radiation monitor includes a radiation source in the sensor section in order to check whether the sensor section is normally operating. However, it is assumed from now on that regulation on handling of radioactive materials is made stricter, so that a radiation monitor that can check soundness of the operation of the sensor section without using a radiation source is required. The same can be said for other detection elements, such as those using a scintillator or photomultiplier.
[0004] In response to the above demand, a configuration in which an LED (Light Emitting Diode) is used in place of the radiation source is adopted. This configuration is achieved by using characteristics that the detection element has sensitivity with respect also to light. Meanwhile, in a detection element using a semiconductor, inappropriate reverse bias voltage may cause sensitivity, resulting in a false detection. In order to cope with this problem, there is proposed the following method. In this method, an LED is caused to emit optical pulses so as to obtain an output similar to the radiation, and the optical pulses are allowed to irradiate the detection element with the repetition frequency of the optical pulses controlled so as to perform operation check. Through this operation check, presence/absence of abnormality in reverse bias voltage is determined to thereby check the soundness of the operation of the sensor section (refer to, e.g., Japanese Patent Application Laid-Open Publication No. 02-128184, the entire content of which is incorporated herein by reference).
[0005] As described above, the above prior art is configured to detect the abnormality in the bias voltage by using an LED. Further, at present, strongly desired is a configuration capable of performing check of the soundness of the sensor section at any time, without influencing radiation measurement, from a monitor module section remotely installed from the sensor section.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention has been made in view of the above situation, and an object thereof is to provide a radiation monitor and its operation check method capable of performing check of the soundness of the sensor section at any time, without influencing radiation measurement, from a monitor module section remotely installed from the sensor section.
[0007] According to the present invention, there is provided a radiation monitor comprising a sensor section and a monitor module section which are disposed separately from each other and connected to each other via a signal transmission path, wherein the sensor section comprises: a detection element that detects radiation and has sensitivity with respect also to light, a signal processing section that converts an output from the detection element into an electric signal for output, a light emitting element that irradiates the detection element with light, and a light emission control circuit that controls the light emission of the light emitting element; the monitor module section comprises: a counter circuit section that counts the number of electric signals transmitted thereto from the signal processing section; a radiation amount calculation/display section that calculates radiation amount from the output of the counter circuit section and displays the calculation result; an abnormality determination/display section that determines whether the output of the counter circuit section is an abnormal value and displays the determination result; a switching section that switches the output destination of the counter circuit section between the radiation amount calculation/display section and the abnormality determination/display section; a timer section that outputs a timing signal at a constant timing; and a sensor operation check mode determination section that determines whether a sensor operation check mode is active based on the timing signal of the timer section and the amount of radiation output from the radiation amount calculation/display section and transmits a determination result signal indicating whether the sensor operation check mode is active to the switching section, the radiation amount calculation/display section, the abnormality determination/display section, and the light emission control circuit; and the signal transmission path transmits an output signal from the signal processing section to the counter circuit section and transmits a signal from the sensor operation check mode determination section to the light emission control circuit.
[0008] According to the present invention, there is provided a method for checking operation of a radiation monitor that monitors radiation by transmitting an output from a sensor section having a detection element that can detect light and radiation to a monitor module section via a signal transmission path, wherein a period during which a sensor operation check mode is not active and a period at which the sensor operation check mode is active are alternately repeated every predetermined time, while the sensor operation check mode is active, optical pulses are generated at a predetermined frequency during the sensor operation check mode, the optical pulses are detected by means of the detection element of the sensor section, the detection output is transmitted to the monitor module section for counting, and presence/absence of abnormality in sensor operation of the sensor section is determined based on whether the counted value falls within a predetermined range.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The above and other features and advantages of the present invention will become apparent from the discussion hereinbelow of specific, illustrative embodiments thereof presented in conjunction with the accompanying drawings, in which:
[0010] FIG. 1 is a configuration diagram of a first embodiment of the present invention;
[0011] FIG. 2 is a diagram for explaining a change in the count rate in the first embodiment;
[0012] FIG. 3 is a configuration diagram of a second embodiment of the present invention; and
[0013] FIG. 4 is a configuration diagram of a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Embodiments of the present invention will be described below with reference to the accompanying drawings.
First Embodiment
[0015] A first embodiment will be described with reference to FIGS. 1 and 2 . FIG. 1 is a diagram schematically illustrating a configuration of the first embodiment, and FIG. 2 is a diagram for explaining a change in the count rate.
[0016] As illustrated in FIG. 1 , a radiation monitor 1 includes: a sensor section 2 that is disposed at a location where radiation detection is required; a monitor module section 3 that is disposed at a location remote from the sensor section 2 , such as a monitoring room or a central operation room; and monitors radiation, and a signal transmission path 4 that connects the sensor section 2 and monitor module section 3 and performs signal transmission between them. The signal transmission path 4 includes: a first transmission path 5 that is implemented as one cable and transmits signals from the sensor section 2 to the monitor module section 3 ; and a second transmission path 6 that is implemented as one cable and transmits signals from the monitor nodule section 3 to the sensor section 2 .
[0017] The sensor section 2 includes: a detection element 7 that detects radiation and has sensitivity with respect also to light, and a signal processing section 8 that converts a detection output from the detection element 7 into an electric signal for output. The sensor section 2 further includes a light emitting element 9 such as a light-emitting diode (LED) that generates optical pulses and irradiates the detection portion of the detection element 7 with the optical pulses; and a light emission control circuit 10 that controls the pulse emission of the light emitting element 9 occurring at a predetermined frequency, ON/OFF of the pulse emission, and intensity of the pulse emission. The sensor section 2 is configured to operate by power supplied, via a power supply line 11 a and not-illustrated lines in the sensor section, from a sensor section power source 11 installed near the sensor section 2 . The detection element 7 is formed of a semiconductor device which is made of, e.g., silicon or cadmium telluride and has sensitivity with respect both to light and radiation. Alternatively, the detection element 7 may be formed of a scintillator or photomultiplier having sensitivity with respect both to light and radiation. The optical pulse may be selected in accordance with the characteristics of the detection element 7 and light emitting element 9 and may be an optical pulse in the visible light region, optical pulse in the ultraviolet light region or optical pulse in the infrared light region.
[0018] The monitor module section 3 includes: a counter circuit section 12 that counts the number of electric signals transmitted thereto from the signal processing section 8 of the sensor section via the first transmission path 5 ; a radiation amount calculation/display section 13 that calculates radiation amount from the output of the counter circuit section 12 and displays the calculation result; an abnormality determination/display section 14 that compares the output of the counter circuit section 12 with a predetermined reference value to determine whether the output of the counter circuit section 12 is an abnormal value and displays the determination result; and a switching section 15 that has an input terminal connected to the output side of the counter circuit section 12 , a first output terminal connected to the radiation amount calculation/display section 13 , and a second output terminal connected to the abnormality determination/display section 14 , and switches the output destination of the counter circuit section 12 between the radiation amount calculation/display section 13 and the abnormality determination/display section 14 .
[0019] The monitor module section 3 further includes a timer section 16 that outputs a timing signal at a constant timing, and a sensor operation check mode determination section 17 . The sensor operation check mode determination section 17 determines whether a sensor operation check mode is active based on the timing signal of the timer section 16 and the amount of radiation output from the radiation amount calculation/display section 13 , and transmits a determination result signal indicating whether the sensor operation check mode is active to the switching section 15 , the radiation amount calculation/display section 13 and the abnormality determination/display section 14 . The determination result signal is further transmitted to the light emission control circuit 10 of the sensor section 2 via the second transmission path 6 .
[0020] The monitor module section 3 is configured to operate by power supplied from a not-illustrated monitor module power source.
[0021] The sensor operation check mode determination section 17 is configured to receive the timing signal at a constant period from the timer section 16 and, in response to the timing signal, enters the sensor check mode for a predetermined time period. In the case where the output of the sensor section 2 exhibits a high count rate and where the radiation amount calculated by the radiation amount calculation/display section 13 is not less than a predetermined certain value, the sensor operation check mode determination section 17 does not enter the sensor check mode for allowing detection of whether the sensor section 2 is in a failed state of being insensitive to radiation. That is, assume that, for example, a failed state is not allowed to continue for five minutes or more. In this configuration, in the case where a signal corresponding to radiation is counted every ten minutes, the sensor check mode is activated one or more times every five minutes; on the other hand, in the case where a signal corresponding to radiation is counted every one minute, the sensor check mode need not be activated.
[0022] In the sensor check mode, the switching section 15 switches the output destination of the counter circuit section 12 from the radiation amount calculation/display section 13 to the abnormality determination/display section 14 and transmits the determination result signal indicating that the sensor operation check mode is active to the light emitting control circuit 10 , the radiation amount calculation/display section 13 and the abnormality determination/display section 14 . During reception of the determination result signal indicating that the sensor operation check mode is active, i.e., only in the time period during which the sensor check mode is active, the light emission control circuit 10 controls the light emitting element 9 to emit optical pulses at a predetermined frequency to thereby irradiate the detection portion of the detection element 7 with the optical pulses. After termination of the sensor check mode, the switching section 15 switches the output destination of the counter circuit section 12 from the abnormality determination/display section 14 to the radiation amount calculation/display section 13 and stops the transmission of the determination result signal indicating that the sensor operation check mode is active to the light emitting control circuit 10 , the radiation amount calculation/display section 13 and the abnormality determination/display section 14 .
[0023] The abnormality determination/display section 14 determines presence/absence of abnormality depending on whether the counting number of the counter circuit section 12 per unit time falls within a predetermined range while the sensor check mode is active. In addition to the function of determining presence/absence of abnormality, the abnormality determination/display section 14 may have a function of self-diagnosing a circuit so as to check the operating voltage or operation state of a CPU, etc. Further, in addition to the function of displaying the determination result, the abnormality determination/display section 14 may have a function of outputting a signal notifying sections other than the monitor module section 3 of the abnormality determination result.
[0024] While the sensor check mode is not active, the radiation amount calculation/display section 13 receives the value output from the counter circuit section 12 and performs calculation of the radiation amount. While the sensor check mode is active, the radiation amount calculation/display section 13 stops the radiation amount calculation and retains a value that has been acquired most recently, i.e., a value of the radiation amount output from the counter circuit section 12 that has been acquired immediately before the activation of the sensor operation check mode.
[0025] A state before and after the period during which the sensor check mode is active is illustrated in FIG. 2 . In FIG. 2 , T denotes a period during which the sensor check mode is active, Tx and Ty denote periods before and after the sensor check mode, respectively, the upper side graph represents a state of a pulse signal A to be input to the counter circuit section 12 , and the lower side graph represents a radiation amount B calculated by the radiation amount calculation/display section 13 .
[0026] As illustrated in FIG. 2 , the pulse signal to be input to the counter circuit section 12 is input to the abnormality determination/display section 14 while the sensor check mode is active, so that no pulse signal is input to the radiation amount calculation/display section 13 . Here, assuming that the radiation amount calculation/display section 13 performs calculation of the count rate with a time constant decay taken into consideration, when the radiation amount calculation/display section 13 continues decay calculation even during the sensor check mode, the count rate becomes too low at the time point at which the sensor check mode is ended, as denoted by broken curve in the lower side graph.
[0027] In order to prevent the count rate from being too low, the radiation amount calculation/display section 13 does not perform the decay calculation during the sensor check mode but retains the value that has been acquired immediately before the activation of the sensor check mode. In addition to the function of calculating the radiation amount, the radiation amount calculation/display section 13 may have a function of changing a setting value for the calculation. Further, in addition to the function of displaying the radiation amount obtained through the calculation or setting value, the radiation amount calculation/display section 13 may have a function of outputting a signal notifying sections other than the monitor module section 3 of the calculation result of the radiation amount or setting value.
[0028] Thus, the radiation monitor 1 can be configured to periodically perform operation check using optical pulses when the radiation amount is not more than a certain value without influencing radiation measurement itself.
[0029] Although the switching section 15 is used to switch the output destination of the counter circuit section 12 , a configuration that does not use the switching section 15 may be employed. In this configuration, the output of the counter circuit section 12 is simultaneously input to the radiation amount calculation/display section 13 and the abnormality determination/display section 14 . Then, when the mode determined by the sensor operation check mode determination section 17 is the sensor check mode, the radiation amount calculation/display section 13 is made to stop a calculation process of converting the output of the counter circuit section 12 into the radiation amount; on the other hand, when the mode determined by the sensor operation check mode determination section 17 is not the sensor check mode, the radiation amount calculation/display section 13 is made to perform the calculation process. Further, although the first transmission path 5 and the second transmission path 6 of the signal transmission path 4 connecting the sensor section 2 and the monitor module section 3 are constituted by two cables, the signal transmission path 4 may be constituted by more cables for transmission of, e.g., digital values. Further, the first transmission path 5 and the second transmission path 6 may be implemented in a single cable having a plurality of set of signal/ground lines.
Second Embodiment
[0030] A second embodiment will be described with reference to FIG. 3 . FIG. 3 is a diagram schematically illustrating a configuration of the second embodiment. The second embodiment differs from the first embodiment in a configuration of the signal transmission/reception part between the sensor section and monitor module section but operates in the same manner as the first embodiment. The same reference numerals as those in the first embodiment are given to the same or corresponding parts as those in the first embodiment, and the descriptions thereof will be omitted here. In the following, only the different point from the first embodiment will be described.
[0031] As illustrated in FIG. 3 , a radiation monitor 21 includes: a sensor section 22 that is disposed at a location where radiation detection is required; a monitor module section 23 that is disposed at a location remote from the sensor section 22 , such as a monitoring room or a central operation room; and a single signal transmission path 24 that connects the sensor section 22 and the monitor module section 23 , and performs signal transmission between them. The signal transmission path 24 includes one cable that uses a single transmission path to transmit, in a superimposing manner, reverse direction signals, i.e., a signal from the sensor section 22 to the monitor module section 23 and a signal from the monitor module section 23 to the sensor section 22 .
[0032] The sensor section 22 includes a detection element 7 , signal processing section 8 , a light emitting element 9 , and a light emission control circuit 10 that have the same configuration as those in the first embodiment. The sensor section 22 further includes a sensor-side signal decode/encode section 25 serving as a sensor-side transmission/reception section for transmitting/receiving signals between the sensor section 22 and the monitor module section 23 . The sensor section 22 is configured to operate by a power supplied, via the power supply line 11 a and not-illustrated lines in the sensor section, from a sensor section power source 11 . The monitor module section 23 includes a counter circuit section 12 , a radiation amount calculation/display section 13 , an abnormality determination/display section 14 , a switching section 15 , a timer section 16 , and sensor operation check mode determination section 17 that have the same configuration as those in the first embodiment. The monitor module section 23 further includes a monitor module-side signal decode/encode section 26 serving as a monitor module-side transmission/reception section for transmitting/receiving signals between the monitor module section 23 and the sensor section 22 .
[0033] The sensor-side signal decode/encode section 25 of the sensor section 22 has: an input terminal connected to the output terminal of the signal processing section 8 , an output terminal connected to the input terminal of the light emission control circuit 10 , and an input/output terminal connected to one end of the signal transmission path 24 . The monitor module-side signal decode/encode section 26 of the monitor module section 23 has: an output terminal connected to the input terminal of the counter circuit section 12 , an input terminal connected to the output terminal of the sensor operation check mode determination section 17 , and an input/output terminal connected to the other end of the signal transmission path 24 .
[0034] With the above configuration, the sensor-side signal decode/encode section 25 of the sensor section 22 transmits the output of the signal processing section 8 , which is an electric signal converted from the detection output of the detection element 7 , to the monitor module section 23 via the signal transmission path 24 while receiving the determination result signal of the sensor operation check mode determination section 17 output from the monitor module-side signal decode/encode section 26 with the both signals superimposed on each other. The monitor module-side signal decode/encode section 26 of the monitor module section 23 transmits the determination result signal of the sensor operation check mode determination section 17 to the sensor section 22 via the signal transmission path 24 while receiving the output of the signal processing section 8 from the sensor-side signal decode/encode section 25 with the both signals superimposed on each other.
[0035] As a result, the transmission/reception of signals between the sensor section 22 and the monitor module section 23 can be performed by means of the single transmission path 24 , thereby achieving the same effect as that of the first embodiment. In addition, the number of transmission paths required for connecting the sensor section 22 and the monitor module section 23 can be reduced. Particularly, in a case where the sensor section 22 and the monitor module section 23 are installed remotely from each other, component cost or installation time/cost can be reduced.
Third Embodiment
[0036] A third embodiment will be described with reference to FIG. 4 . FIG. 4 is a diagram schematically illustrating a configuration of the third embodiment. The third embodiment differs from the first embodiment and the second embodiment in configurations of the signal transmission/reception part between the sensor section and the monitor module section, and the power supply part for supplying power to the sensor section, but operates in the same manner as the first and second embodiments. The same reference numerals as those in the first embodiment and the second embodiment are given to the same or corresponding parts as those in the first and second embodiments, and the descriptions thereof will be omitted here. In the following, only the different points from the first embodiment and the second embodiment will be described.
[0037] As illustrated in FIG. 4 , a radiation monitor 31 includes: a sensor section 32 that is disposed at a location where radiation detection is required; a monitor module section 33 that monitors radiation at a location remote from the sensor section 32 , such as a monitoring room or a central operation room; and a single signal/power transmission path 34 that connects the sensor section 32 and the monitor module section 33 , and performs signal transmission between them as well as supplies power to the sensor section 32 . The signal/power transmission path 34 includes one power cable that uses a single transmission path to transmit, in a superimposing manner, reverse direction signals, i.e., a signal from the sensor section 32 to the monitor module section 33 and a signal from the monitor module section 33 to the sensor section 32 and power to be supplied to the sensor section 32 , or includes one composite cable incorporating, in one sheath, a signal line for transmitting signals in a superimposing manner and a power line for supplying power.
[0038] The sensor section 32 includes a detection element 7 , a signal processing section 8 , a light emitting element 9 , and a light emission control circuit 10 that have the same configuration as those in the first embodiment. The sensor section 32 further includes a sensor-side signal decode/encode and power supply section 35 serving as a sensor-side transmission/reception and power supply section for transmitting/receiving signals between the sensor section 32 and the monitor module section 33 and receiving power. The sensor section 32 is configured to operate by a power supplied, via the signal/power transmission path 34 , the sensor-side signal decode/encode and power supply section 35 , and not-illustrated lines in the sensor section, from the sensor section power source 11 provided in the monitor module section 33 . The monitor module section 33 includes a counter circuit section 12 , a radiation amount calculation/display section 13 , an abnormality determination/display section 14 , a switching section 15 , a timer section 16 , and a sensor operation check mode determination section 17 that have the same configuration as those in the first embodiment. The monitor module section 33 further includes a monitor module-side signal decode/encode and power superimposition section 36 serving as a monitor module-side transmission/reception and power supply section for transmitting/receiving signals between the monitor module section 33 and the sensor section 32 and transmitting power.
[0039] The sensor-side signal decode/encode and power supply section 35 of the sensor section 32 has: a signal input terminal connected to the output terminal of the signal processing section 8 , a signal output terminal connected to the input terminal of the light emission control circuit 10 , a not-illustrated power output terminal connected to lines in the sensor section, and an input/output terminal connected to one end of the signal/power transmission path 34 . The monitor module-side signal decode/encode and power superimposition section 36 of the monitor module section 33 has: a signal output terminal connected to the input terminal of the counter circuit section 12 , a signal input terminal connected to the output terminal of the sensor operation check mode determination section 17 , a power input terminal connected to the power supply line 11 a connected to the sensor section power source 11 , and an input/output terminal connected to the other end of the signal/power transmission path 34 .
[0040] With the above configuration, the sensor-side signal decode/encode and power supply section 35 of the sensor section 32 transmits the output of the signal processing section 8 , which is an electric signal converted from the detection output of the detection element 7 , to the monitor module section 33 via the signal/power transmission path 34 while receiving the determination result signal of the sensor operation check mode determination section 17 output from the monitor module-side signal decode/encode and power superimposition section 36 with the both signals and power superimposed on one another or in such a manner that the superimposed signal of the both signals and power are transmitted/received on different lines. The monitor module-side signal decode/encode and power superimposition section 36 of the monitor module section 33 supplies power and transmits the determination result signal of the sensor operation check mode determination section 17 to the sensor section 32 via the signal/power transmission path 34 while receiving the output of the signal processing section 8 from the sensor-side signal decode/encode and power supply section 35 with the both signals superimposed on each other.
[0041] As a result, the transmission/reception of signals and power supply/reception between the sensor section 32 and the monitor module section 33 can be performed by means of the single transmission path 34 , thereby achieving the same effect as that of the first embodiment. In addition, the number of transmission paths required for connecting the sensor section 32 and the monitor module section 33 can be reduced. Particularly, in the case where the sensor section 32 and the monitor module section 33 are installed remotely from each other, component cost or installation time/cost can be reduced. Furthermore, it is possible to eliminate the need to ensure the sensor section power source 11 for the sensor section 32 at the site where radiation is detected, making the structure of the sensor section 32 simple.
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A sensor section is provided with a detection element sensitive to light and radiation so that normal operation of the sensor section can be confirmed. The function for confirming operation of the sensor section using an optical pulse signal from a light emitting element is controlled from a monitor module section for connection with the sensor section. When the optical pulse for confirming operation of the detection element is generated, output from the sensor section is excluded from operation at the monitor module section so that confirmation of operation by an optical pulse is not affected. Furthermore, a configuration for stopping the sensor operation confirmation function when the output from the sensor section is high counting rate is provided over both the sensor section and the monitor module section.
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RELATED APPLICATIONS
The present invention is a national stage filing of International Application No. PCT/US2007/022733, filed Oct. 26, 2007, which claims priority from U.S. Provisional Application Ser. No. 60/855,089 filed Oct. 27, 2006, entitled “Manufacture of Lattice Truss Sandwich Structures from Monolithic Materials” and U.S. Provisional Application Ser. No. 60/963,790 filed Aug. 7, 2007, entitled “Manufacture of Lattice Truss Sandwich Structures from Monolithic Materials” the disclosures of which are hereby incorporated by reference herein in their entirety.
GOVERNMENT SUPPORT
Work described herein was supported by Federal Grant No. ONR Grant No. N00014-01-1-1051, awarded by Office of Naval Research. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
Lightweight sandwich panel structures consisting of low density cores and solid facesheets are widely used in engineering applications. Cellular core structures based upon honeycomb topologies are often used because of their high compressive strength-to-weight ratios and high bending stiffness. These honeycomb structures are close-celled with limited access into the core regions. The cores may be attached to the facesheets or plates by conventional joining methods, such as adhesive bonding, brazing, diffusion bonding and welding. Recently, lattice truss structures have been explored as an alternate cellular core topology. Pyramidal lattice truss structures are usually fabricated from high ductility alloys by folding a perforated metal sheet along the perforations, creating accordion-like structures. Conventional joining methods such as brazing or laser welding are then used to bond the core to solid facesheets, forming sandwich structures. The lattice topology, core relative density, and parent alloy mechanical properties, along with the bond strengths, determine the mode of truss deformation and, therefore, the out-of-plane and in-plane mechanical properties of these structures.
The design of the core-facesheet node interface is of the utmost importance. Ultimately, this dictates the maximum load that can be transferred from the facesheets to the core. Node bond failure has been identified as a failure mode for sandwich structures, especially metallic honeycombs. However, analogous node failure modes have been observed in sandwich panels utilizing tetragonal and pyramidal lattice truss cores during shear loading. Assuming sufficient core-faceplate bond (facesheet-bond) strength and ductility, when sandwich panels are subjected to intense shear or bending loads, the nodes transfer forces from the facesheets to the core members and the topology for a given core relative density dictates the load carrying capacity. When the node-facesheet interfacial strength is compromised by poor joint design or inadequate bonding methods, node bond failure occurs resulting in premature failure of the sandwich panel. Numerous factors determine the robustness of nodes, including joint composition, microstructure, degree of porosity, geometric effects (which control stress concentrations) and the nodes' contact area.
Micromechanical models for the stiffness and strength of pyramidal lattice truss cores, comprising elastic-plastic struts with perfect nodes have been recently developed. These models assumed that the trusses are connected to rigid face sheets and are of sufficiently low aspect ratio that bending effects make a negligible contribution to the stiffness and strength. These micromechanical models also assume the node strength is the same as the parent metal alloy. However, the measured elastic moduli rarely reach the predicted values because of variations in the length of the trusses and small initial departures from straightness introduced by manufacturing processes.
The design of the core-to-facesheet interface in honeycomb sandwich panels is of utmost importance. Ultimately, this dictates the amount of load that can be transferred from the face sheets to the core. This is even more critical for lattice-based cores since they can have a smaller node area than honeycombs of the same core density. Node bond failure has been identified as a key catastrophic failure mode for metallic honeycomb sandwich structures (See Bitzer, 1997). Similar node robustness problems have been observed in lattice-based sandwich structures. When sandwich panels are subjected to shear or bending loads, the nodes transfer forces from the facesheets to the core, assuming adequate node bond strength exists, and the topology for a given core relative density dictates the load carrying capacity. When the core-facesheet interface strength is compromised by poor joint design or weak bonding methods, node failure occurs and catastrophic failure of the sandwich panel results. Although numerous factors (including joint composition, microstructure, degree of porosity, and geometric constraints) determine the robustness of nodes, the node contact area serves as a critical limiting factor in determining the maximum force that can be transmitted across the core-facesheet interface.
Initial efforts to fabricate millimeter scale structures employed investment casting of high fluidity casting alloys such as copper/beryllium (See Wang et al., 2003), aluminum/silicon (See Deshpande et al., 2001, Deshpande and Fleck, 2001, Wallach and Gibson, 2001, Zhou et al., 2004), and silicon brass (See Deshpande and Fleck, 2001). Investment casting begins with the creation of a wax or polymer pattern of the lattice truss sandwich structure. The sandwich structure is attached to a system of liquid metal gates, runners, and risers that are made from a casting wax. The whole assembly is coated with ceramic casting slurry. The pattern is then removed and the empty (negative) pattern filled with liquid metal. After solidification, the ceramic, gates, and runners are removed, leaving behind a lattice based sandwich structure of homogeneous metal. However, the tortuosity of the lattices made it difficult to fabricate high-quality investment-cast structures at the low relative density (2-10%) needed to optimize sandwich panel constructions (See Chiras et al., 2002). In addition, the inherent low quality of as-cast metals resulted in sandwich structures that lacked the robustness required for the most demanding structural applications (See Sugimura, 2004).
The toughness of many wrought engineering alloys is evidenced by development of alternative fabrication approaches based upon perforated metal sheet folding (See Sypeck and Wadley, 2002). These folded truss structures could be bonded to each other or to facesheets by either transient liquid phase (TLP) bonding or micro welding techniques to form lattice-truss sandwich panels. Panels fabricated with tetrahedral (See Sypeck and Wadley, 2002, Rathbun et al., 2004, Lim and Kang, 2006) and pyramidal lattice-truss (See Zok et al., 2004, Queheillalt and Wadley, 2005, McShane et al., 2006, Radford, et al. 2006) topologies have been made by the folding and brazing/TLP bonding method. However, the node bond strength and the topology for a given core relative density may dictate the load-carrying capacity. While these structures are much more robust than their investment cast counterparts, their robustness may be dictated by the quality of the bond between the core and facesheets.
A detailed description of the fabrication approach for making 6061 aluminum alloy lattice truss structures can be found in Multifunctional Periodic Cellular Solids and the Method of Making the Same (PCT/US02/17942, filed Jun. 6, 2002), Method for Manufacture of Periodic Cellular Structure and Resulting Periodic Cellular Structure (PCT/US03/16844, filed May 29, 2003), and Methods for Manufacture of Multilayered Multifunctional Truss Structures and Related Structures there from (PCT/US2004/004608, filed Feb. 17, 2004), of which all of the PCT Applications are hereby incorporated by reference herein in their entirety. Briefly, these patents describe a folding process used to bend perforated sheets to create a single or multiple-layered lattice truss structures. The folding is accomplished using a paired punch and die tool or a finger break to fold node rows into the desired truss structure. The lattice truss core is then joined to facesheets via one of the previously mentioned methods to form the lattice truss sandwich structure (i.e. adhesives, welding, brazing, soldering, transient liquid phase sintering, etc.).
SUMMARY OF INVENTION
Provided herein are exemplary methods and systems to manufacture lattice-based sandwich structures from monolithic material. Such methods and systems eliminate the bonding process which is conventionally used to join lattice based truss cores to facesheets to form sandwich structures. This bonded interface is a key mode of failure for sandwich structures which are subjected to shear or bending loads because the nodes transfer forces from the face sheets to the core members while the topology for a given core relative density dictates the load carrying capacity (assuming adequate node-bond strength exists).
An aspect of an embodiment of the present invention comprises a core and related structures that provide very low density, good crush resistance and high in-plane shear resistance. An aspect of the truss structures may include sandwich panel cores and lattice truss topology that may be designed to efficiently support panel bending loads while maintaining an open topology that facilitates multifunctional applications.
Some aspects of various embodiments of the present invention method and system utilize, but are not limited to, novel methodologies to construct sandwich structures without using adhesives, diffusion bonding, brazing, soldering, or resistance/electron/laser welding or coupling to join the cores to the facesheets to form sandwich structures. Facesheet-core interface bond failure (e.g., facesheet-core interface) may be a key failure mode for lattice based sandwich structures. When lattice based sandwich panels are subjected to shear or bending loads, the nodes transfer forces from the face sheets to the core members (assuming adequate node bond strength exists) and the topology (for a given core relative density) dictates the load carrying capacity. However, when the node-facesheet interface strength is compromised, node failure occurs and catastrophic failure of the sandwich panel results.
Some aspects of various embodiments of the present invention method and system may utilize, but are not limited thereto, a two-step manufacturing process. A prismatic structure is extruded forming a 3D structure with a constant cross section along the path of extrusion; thereafter a secondary operation is used to selectively remove material, from the core region, forming a 3D lattice truss sandwich structure. This process can be used for any metal, including (but not limited thereto) steel, aluminum, copper, magnesium, nickel, titanium alloys, etc., and is highly suited for alloys that possess limited ambient temperature ductility.
It should be appreciated that the method of manufacture/fabrication may be altered or adjusted in interest of creating a resultant structure that is ultimately desired or required.
An aspect of an embodiment of the present invention provides a method of creating a monolithic lattice truss or truss-based structure (or related structure as desired or required). The method comprising: providing a monolithic sample; extruding the monolithic sample to selectively remove material along a first path; and machining the monolithic sample to selectively remove material along a second path, wherein the first path and the second path are offset at a desired offset angle to create one or a plurality of truss unit portions. Multiple paths and various types of paths and respective locations and angles may be applied as desired or required to achieve the desired method or structure.
An aspect of an embodiment of the present invention provides a method of creating a monolithic lattice truss structure (or related structure as desired or required). The method comprising: providing a monolithic sample; machining the monolithic sample to selectively remove material along a first path; and machining the monolithic sample to selectively remove material along a second path, wherein the first path and the second path are offset at a desired offset angle to create one or a plurality of truss unit portions. Multiple paths and various types of paths and respective locations and angles may be applied as desired or required to achieve the desired method or structure.
An aspect of an embodiment of the present invention provides a monolithic lattice truss structure (or related structure as desired or required). The structure comprising: one or a plurality of truss unit portions, wherein the truss unit portions have the same metallurgical and microstructural properties.
An aspect of an embodiment of the present invention provides a structure that is manufactured or fabricated in whole or in part and by any one or combination of the manufacturing or fabrication methods discussed herein.
These and other objects, along with advantages and features of the invention disclosed herein, will be made more apparent from the description, drawings and claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the instant specification, illustrate several aspects and embodiments of the present invention and, together with the description herein, and serve to explain the principles of the invention. The drawings are provided only for the purpose of illustrating select embodiments of the invention and are not to be construed as limiting the invention.
FIGS. 1 (A)-(C) provide schematic illustrations of three stages of the manufacturing method utilizing two arrays of channels EDM cut into a monolithic block of metal forming a pyramidal lattice truss sandwich structure.
FIGS. 2 (A)-(B) provide schematic illustrations of two of the stages of the manufacturing method utilizing a single array of channels EDM cut into an extruded prismatic sandwich structure forming a pyramidal lattice truss sandwich structure.
FIG. 3 provides a photographic depiction of a pyramidal lattice sandwich structure which was EDM cut from a 6061 aluminum alloy extrusion.
FIGS. 4 (A)-(B) provide schematic illustrations of two of the stages of the manufacturing method of a double-layer pyramidal lattice sandwich structure with aligned nodes between adjacent layers and a double array of channels EDM cut into an extruded double-layer prismatic sandwich structure.
FIG. 5 provides a schematic illustration of the extrusion process used to produce 6061 aluminum corrugated sandwich structures.
FIGS. 6 (A)-(B) provide schematic illustrations of the regions in the corrugated core that are removed by electro discharge machining to create a pyramidal lattice core sandwich panel structure.
FIG. 7 provides a photographic depiction of an extruded/electro discharge machined pyramidal lattice sandwich structure with a core relative density of 6.2%.
FIG. 8(A) graphically illustrates the compressive stress verses strain response. Predictions of the stress for inelastic buckling and plastic yielding of the trusses are also shown.
FIGS. 8 (B)-(G) provide photographic depictions of the lattice deformation at strain levels (ε) of 0, 5, 10, 15, 20 and 25%, respectively.
FIG. 9(A) graphically illustrates the shear stress verses shear strain response. Predictions of the stress for inelastic buckling and plastic yielding of the trusses are also shown.
FIGS. 9 (B)-(D) provide photographic depictions of the lattice deformation at strain levels (γ) of 0, 6 and 12%, respectively.
FIGS. 10 (A)-(B) graphically illustrates the normalized (a) compression and (b) shear stiffness measurements, respectively, versus strain.
FIG. 11 provides a schematic illustration of one embodiment of a sandwich structure of the p-JBD system interacting with a jet.
FIGS. 12 (A)-(C) provide schematic illustrations of an embodiment of a sandwich structure demonstrating blast or explosion mitigation in response to an explosion. FIGS. 12 (A)-(C) provide the impulse loading stage, core crushing stage, and panel bending stage, respectively.
FIGS. 13 (A)-(D) provide schematic illustrations of an embodiment of a sandwich structure 1201 demonstrating projectile arresting capabilities in response to a projectile, which provides various rupture and fracture details.
DETAILED DESCRIPTION OF THE INVENTION
As described earlier, a variety of lattice topologies can be fabricated from ductile metals using current fabrication methods that rely on cutting, stamping and/or bending processes to form the desired lattice core, which is then subsequently bonded to facesheet by a variety of methods including, but not limited to, adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, coupling, etc. The design of the core-to-facesheet interface is of utmost importance. Ultimately, this dictates the amount of load that can be transferred from the facesheets to the core, and, ultimately, supported by the truss assembly.
Provided herein, an aspect of an embodiment provides methods and systems that result in sandwich structures with highly robust nodes that can be manufactured from any metal, including, but not limited to steel, aluminum, copper, magnesium, nickel, titanium alloy, etc. These methods are well-suited for alloys that possess limited ambient temperature formability.
The following are exemplary methods and systems of various embodiments of the present invention that can be used to fabricate lattice truss sandwich structures (or any structure as desired/required) from any metal, thus greatly expanding the realm of metals that can be fabricated into cellular structures, as the aforementioned methods (adhesives, diffusion bonding, brazing, soldering or resistance/electron/laser welding, etc.) could only have been fabricated from alloys. In addition, since there is no metallurgical or microstructural discontinuity at the truss-facesheet (truss-faceplate) interface region, the likelihood of corrosion is greatly reduced.
In an exemplary and non-limiting embodiment of an aspect of the present invention, a pyramidal lattice sandwich structure is formed from a solid monolithic sample 1 , such as a piece of metal, but not limited thereto. The initial monolithic sample 1 can be sheet, plate, ingot, billet, powder compact, or slurry, or the like, form depending on the size of the final sandwich structure or any desired/required structure. The following is a description for the manufacture of a pyramidal lattice. It should also be appreciated, however, that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures may be manufactured via this method as desired or required. FIG. 1(A) shows an example of a solid, monolithic sample 1 . FIG. 1(B) shows an example of a triangulated pattern machined in the y-direction. This pattern can be machined via electro discharge machining, drilling including laser drilling and other ablative removal techniques in which material is melted or evaporated, cut, water jet cutting, chemical dissolution methods or any other suitable operation. At this point, the structure has the form of a 2D prismatic sandwich structure 2 with facesheets 11 and a consistent cross-section along the y-axis. FIG. 1(C) shows an example of a triangulated pattern machined in the x-direction. Again, this pattern can be machined via electro discharge machining, cutting or any other suitable operation. The result of the combination of these two processes is a 3D lattice truss sandwich structure 3 with facesheets 11 enclosing truss units 12 , forming nodes 13 where a truss units 12 interfaces with a facesheet 11 . The truss units 12 comprise of a plurality of legs or ligaments 14 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 12 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. Moreover, while the various paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. In an embodiment, the monolithic sample 1 may comprise at least one select material as desired or required. In an embodiment, the select material may comprise, for example but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be machined along a plurality of paths, such as two or more as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the faceplate or facesheet and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
In an exemplary and non-limiting embodiment of an aspect of the present invention, a pyramidal lattice sandwich structure is formed from an extruded prismatic structure. The extruded prismatic structure can take on a variety of shapes, dependent only upon the desired topology of the final sandwich structure or any desired/required structure. Again, the following is a description for the manufacture of a pyramidal lattice. It is envisioned, however, that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures may be manufactured via this method. FIG. 2(A) shows an example of an extruded triangulated pattern 21 (extruded direction is the y-direction), with facesheets 11 . FIG. 2(B) shows an example of a triangulated pattern machined in the x-direction of the extruded topology, the combination of these two steps producing a pyramidal lattice sandwich structure. Again, this pattern can be machined via electro discharge machining, cutting, drilling including laser drilling and other ablative removal techniques in which material is melted or evaporated, water jet cutting, chemical dissolution methods or any other suitable operation resulting in the 3D lattice truss sandwich structure 22 with facesheets 11 enclosing truss units 12 , forming nodes 13 where truss legs or ligaments 14 interface with a facesheet 11 . The truss units 12 comprise of a plurality of legs or ligaments 14 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 12 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. Moreover, while the various paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. In an embodiment, the monolithic sample 1 may comprise at least one select material as desired or required. In an embodiment, the select material may comprise, for example, but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be machined along a plurality of paths, such as two or more as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the facesheet or faceplate and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
FIG. 3 provides a photographic depiction of a pyramidal lattice sandwich structure 23 which was EDM cut from a 6061 aluminum alloy extrusion with facesheets 11 enclosing truss units 12 , forming nodes 13 where truss legs or ligaments 14 interfaces with a facesheet 11 .
In an exemplary and non-limiting embodiment of an aspect of the present invention, these manufacturing techniques may be used to form multi-layered sandwich panels. Again, the following is a description for the manufacture of a double-layer pyramidal lattice, however, it is envisioned that tetrahedral, Kagome, cone, frustum, or other lattice-based truss structures of any number of layers may be manufactured via this method. FIG. 4(A) shows an example of a double-layer extruded triangular pattern 31 sandwich structure (extruded direction is the y-direction). FIG. 4(B) shows an example of a triangulated pattern machined in the x-direction of the extruded topology, forming a pyramidal lattice sandwich structure. Again, this pattern can be machined via electro discharge machining, drilling including laser drilling, cutting, removing and other ablative removal techniques in which material is melted or evaporated, water jet cutting, chemical dissolution methods or any other suitable operation. The combination of these two steps produces a multi-layered 3D lattice truss sandwich structure 32 , with facesheets 11 enclosing truss units 12 , forming nodes 13 where truss legs or ligaments 14 interface with a facesheet 11 . It is noted that the alignment of nodes 32 between adjacent layers is not a prerequisite. As with this embodiment or any embodiments discussed herein, each individual layer may be aligned or offset any amount from adjacent layers, yielding the desired properties for the structure as a whole and the layers individually. Similarly, the truss units may have any number of legs or ligaments according to the fabrication approach. The truss units 12 comprise of a plurality of legs or ligaments 14 . The legs may have a variety of shapes such as straight or curved and may have a variety of cross-sections. The plurality of truss units 12 form an array of truss units. While the y-direction path and the x-direction path are shown as substantially straight, it should be appreciate that the paths may be curved or shaped as desired or required. Moreover, while the various paths (x, y, and z) as illustrated appear to be substantially orthogonal or perpendicular respectively with one another, it should be appreciated that any respective angles may be implemented as desired or required for the desired or required fabrication process or resultant truss and/or panel structure. For instance, the array of truss units and panels (or any related components of the resultant structure) may be fabricated so that the truss units and panels (or any related components) may be contoured or shaped as desired or required. In an embodiment, the monolithic sample 1 may comprise at least one select material as desire or required. In an embodiment, the select material may comprise, for example but not limited thereto, ceramic, polymer, metal, metal alloy, and/or any combination of composites thereof (or any material(s) as desired or required. It should be appreciated that the monolithic sample may be machined along a plurality of paths, such as two or more as desired or required. It should be appreciated that the monolithic sample may be extruded along a plurality of paths, such as two or more as desired or required. The area that the faceplate/facesheet and truss units intersect form an interface region. In an embodiment, the interface region has the same metallurgical and microstructural properties. In an embodiment, the truss units have nodes wherein the nodes have the same metallurgical and microstructural properties as the truss unit. In an embodiment, the extruding or machining or both the extruding and machining create the truss units of varying relative density.
Aspects of various embodiments of the present invention provide, but are not limited to, a novel method and system to manufacture lattice-based truss sandwich structures or any desired/required structures that provides enhanced truss-facesheet interface strength by avoiding poor joint design or bonding procedures, which can cause the catastrophic failure of sandwich panels. Although numerous factors determine the robustness of joined nodes (joint composition, microstructure, degree of porosity, geometric constraints, etc.) this new method results in sandwich structures with highly robust nodes that have the equivalent metallurgical, for instance strength, ductility, chemical composition, microstructural characteristics, etc. of the parent material. Aspects of the present invention methods can be used for, but are not limited to, any solid, metal, or metal alloy, including, but not limited to steels, aluminum, copper, magnesium, nickel, titanium alloy, etc. and is highly suited for alloys which possess limited ambient temperature ductility.
This approach can be extended to other material classes. For example, various approaches have been developed for producing polymeric structures with prismatic cores that can then be fabricated via the means described heretofore, including 3D lattice truss sandwich structures. Ceramic materials with prismatic cores can also be fabricated using “green state” extrusion forming and sintering, in which the material can be laterally machined prior to or after a sintering operation. Edge-defined film fed growth also provides a means for fabricating prismatic structures of the type envisioned here from many types of materials, including ceramics (sapphire for example) and semiconductors (such as silicon).
Practice of the invention will be still more fully understood from the following examples and experimental results, which are presented herein for illustration only and should not be construed as limiting the invention in any way.
Example and Experimental Results
An aspect of an embodiment of this invention may comprise an extrusion and electro discharge machining (EDM) method has been developed to fabricate a pyramidal lattice core sandwich structure. The approach is readily extendable to tetrahedral and to multilayer versions of these lattices. In this approach, a 6061 aluminum alloy corrugated core sandwich panel is first extruded, creating an integral core and facesheets, fashioned from a single sample of material. The corrugated core (or any core shape as desired or required) is then penetrated by an alternating pattern of triangular shaped EDM electrodes normal to the extrusion direction to form the pyramidal lattice. The process results in a sandwich panel in which the core-facesheet nodes posses the parent materials' metallurgical and mechanical properties. The out-of-plane compression and in-plane shear mechanical properties of the structure have been measured and found to be very well predicted by analytical estimates.
Referring to FIG. 5 , a sample 41 , such as an extrusion billet for example, comprising 6061 aluminum alloy, was extruded with a regular prismatic structure using extrusion press 43 (as schematically shown by the dotted lines) by a heat source 42 . In this example the heat is applied at 482° C. and the press 43 (having flow channels 45 ) has a dimension of 17.8 cm diameter, 300 ton direct extrusion press at 482° C., resulting in a corrugated core sandwich panel structure 44 , such as a long extrusion stick.
Referring to FIG. 6(A) , after this extrusion step (as shown in FIG. 5 ), the resulting corrugated core sandwich panel structure 44 had a web thickness of 3.2 mm as designated by arrow WT, a core height of 19.1 mm as designated by the arrow CH, and a facesheet thickness of 5.2 mm as designated as FT and a web inclination angle of 60° as designated by arrow WI. The relative density of the corrugated core was 25%. The extruded panels were solutionized, water-quenched and heat-treated to a T6 condition. An alternating pattern of triangular shaped EDM electrodes (not shown) were then inserted normal to the extrusion direction as illustrated in FIG. 6(A) as the patterns to be removed 51 to form the pyramidal lattice sandwich panel, as shown FIG. 6(B) . The triangular plates are shown as cutouts 52 that are perpendicular to the extrusion. The process resulted in a sandwich panel in which the core-facesheet nodes 13 had identical microstructure, composition and mechanical properties to those of the trusses 14 and facesheets 11 .
It should be appreciated that any dimensions or angles shown herein are exemplary and illustrative only and should not be construed as limiting the invention in any way. The sizes, materials, flexibility, rigidness, shapes, contours, angles or dimensions discussed or shown may be altered or adjusted as required or desired.
FIG. 7 shows a photographic depiction of one of the pyramidal lattice sandwich structures. It is 4 unit cells wide by 4 unit cells long as shown by the respective truss-units 12 , and was used for compression measurements. The shear response was measured using samples (not shown) that were 4 unit cells wide and 10 unit cells long.
Test Results
The relative density can be derived for the pyramidal structure depends upon the truss cross sectional area, t 2 , its inclination angle, ω, and length, l. The ratio of the metal volume in a unit cell to that of the unit cell then gives the relative density:
ρ
_
=
2
t
2
l
2
sin
ω
cos
2
ω
·
l
2
cos
2
ω
(
l
cos
ω
+
2
t
)
2
.
(
1
)
For the samples manufactured here, t=3.2 mm, l=24.6 mm and ω=50.77° resulting in a predicted relative density of 6.5%. The experimentally measured relative density was 6.2±0.01%.
The lattice truss structures were tested at ambient temperature in compression and shear at a nominal strain rate of 10 −2 s −1 in accordance with ASTM C365 and C273 using a compression shear plate configuration. A laser extensometer measured the compressive strain by monitoring the displacements of the unconstrained facesheets (with a displacement precision of ±0.001 mm. The shear strain was obtained by monitoring the displacements of the shear plates with a measurement precision of ±0.010 mm.
Referring to FIG. 8 , the through thickness compressive stress—strain response pertaining to the pyramidal lattice sandwich structure substantially shown in FIG. 7 is graphically shown in FIG. 8(A) . FIGS. 8 (B)-(G) show photographic depictions of the lattice deformation at strain levels (ε) of 0, 5, 10, 15, 20 and 25%, respectively. Following an initial linear response, a peak was observed in the compressive stress that coincided with initiation of the buckling of the lattice truss members and the formation of a plastic hinge near the center of the truss members. Continued loading resulted in core softening up to an engineering strain of ˜0.25 at which point the load carrying capacity increased rapidly as the deformed trusses made contact with the facesheets. During the core-softening phase, small fractures were observed to form on the tensile stressed side of the trusses. These were first seen at strains of between 0.10 and 0.12. No failures at the truss-facesheet nodes were observed during any of the tests.
Referring to FIG. 9(A) , the in-plane shear stress—strain response pertaining to the pyramidal lattice sandwich structure substantially shown in FIG. 7 is graphically shown in FIG. 9(A) . FIGS. 9 (B)-(D) show photographic depictions of the lattice deformation at strain levels (γ) of 0, 6 and 12%, respectively. In this test orientation, each unit cell had two truss members loaded in compression and two in tension. The sample exhibited characteristics typical of lattice truss based sandwich cores including: elastic behavior during initial loading and increasing load support capability until the peak strength was reached. Continued loading continued at a constant stress up to a strain of ˜0.13, at which point the sample failed by fracture of the tensile loaded lattice members near their midpoint. Some plastic buckling was observed on truss members at the ends of the sandwich panel. It is a manifestation of the compressive loading component of the ASTM 273 test method. No evidence of node failure was observed during any of the shear experiments.
Tensile coupons of the aluminum 6061 alloy were used to determine the mechanical properties of the parent aluminum alloy. Tensile tests were performed according to ASTM E8 at a strain rate of 10 −3 s −1 . The average Young's modulus, E s , and 0.2% offset yield strength, σ ys , were 69 GPa and 268 MPa, respectively. The tangent modulus, E t , at the inelastic bifurcation stress was 282 MPa.
The peak strength of a lattice truss core is determined by the mechanism of strut failure which, in turn, depends on the cell geometry, strut material properties and the mode of failure loading. Table 1 summarizes the micromechanical predictions for the pyramidal lattice. The micromechanical predictions for the compressive and shear peak strength are shown in FIGS. 8(A) and 9(A) for truss members that fail by plastic yielding or inelastic buckling. There is excellent agreement between the analytical model predictions of the peak strengths and the observed modes of deformation.
The compression and shear stiffnesses were measured from periodic unload/reload measurements. FIG. 10(A) graphically shows the non-dimensional compressive stiffness, Π=E c /(E s ρ ), versus compressive strain (here E c and E s are the Young's moduli of the core and the solid parent alloy respectively, and ρ is, again, the relative density). The predicted non-dimensional compressive stiffness is 0.36. The experimental data fall slightly above 0.36 just prior to attainment of the peak strength and then decrease during the inelastic buckling phase of deformation. FIG. 10(B) graphically shows the non-dimensional shear stiffness, Γ=G c /(E s ρ ), versus shear strain (here G c is the shear stiffness of the core). The predicted non-dimensional shear stiffness of 0.12 and the experimental data are in excellent agreement up until failure of the panel.
Table 1 provides the analytical expressions for the compression and shear stiffness and strength of a pyramidal lattice truss core sandwich structure.
TABLE 1
Mechanical Property:
Analytical Expression:
Compressive stiffness
E c = ρ E s · sin 4 ω
Compressive strength
σ pk = ρ σ ys ·sin 2 ω
(plastic yielding)
Compressive strength
σ pk = ρ σ cr ·sin 2 ω
(inelastic buckling)
Shear stiffness
G
c
=
ρ
_
·
1
8
E
s
·
sin
2
2
ω
Shear strength (plastic yielding)
τ
pk
=
ρ
_
·
1
2
2
σ
ys
·
sin
2
ω
Shear strength (inelastic buckling)
τ
pk
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A new method for fabricating a lattice truss core sandwich panel structure has been developed using a combination of extrusion and electro discharge machining. The approach has been illustrated by the fabrication and mechanical property evaluation of sandwich panels made from a 6061 aluminum alloy; however, the method is applicable to any alloy system that can be easily extruded. For materials that can not be extruded, the electro discharge machining method could be performed in two directions (instead of one as described here) on a monolithic plate resulting in a similar lattice structure. This alternative method, therefore, is extendable to most conductive material systems or other material systems as desired or required.
The measured peak compressive and shear strengths were found to be in excellent agreement with the micromechanical model predictions for the operative truss member failure mechanisms: inelastic buckling for compression and plastic yielding (followed by tensile fracture) for shear. The non-dimensional compression and shear moduli coefficients were found to be in excellent agreement with the analytical predictions.
Conventional sandwich panel structures suffer from node failure during static and dynamic testing. These failures are initiated at defects or in weak or embrittled regions that result from core-faceplate bonding (facesheet bonding) processes. Whereas, the present invention fabrication method described above, results in sandwich panels in which the core-facesheet nodes have identical material properties to those of the trusses and facesheets. Joining methods such as brazing or welding have been eliminated with this process. No evidence of nodal failure was observed during compression or shear loading of the samples fabricated by the method described here.
The method of sandwich panel manufacture described here has been used to fabricate sandwich panels that eliminate the incidence of nodal failures. The panels' mechanical properties are found to be governed only by the geometry of the sandwich panel, the alloy mechanical properties, and the mode of loading. These properties are well predicted by recent micromechanical models.
FIG. 11 is a schematic illustration of one embodiment of p-JBD system 100 interacting with jet 120 . When jet 120 emits a jet blast (not pictured), it interacts with p-JBD 110 or the like. The thermal component of the jet blast is absorbed in to the structure of p-JBD 110 or the like and spread across its surface, and the kinetic component of the jet blast is deflected up and over p-JBD 110 . As the kinetic component passes over the top of p-JBD 110 it must travel over the deployable ejector plate 140 , which creates a low pressure or vacuum region (not pictured) above p-JBD 110 as the kinetic component interacts with the ambient air there. This process pulls cool air 150 , brought into p-JBD 110 through inlet 130 at its base up through the p-JBD structure, thus removing the thermal component of the jet blast stored there. As a result hot air 160 is expelled out the top of p-JBD 110 . It should be appreciated that in some embodiments, p-JBD 110 may be coated with a spray-on non-skid protective surface 170 or any other form of coating designed to provide traction. Passive in this context implies a system that does not necessarily require an active cooling system. Although, it should be appreciated that an active cooling system may be added, supplemented or implemented with the disclosed cooling system and related method disclosed throughout this document regarding the present invention methods and systems. As shown, the p-JBD 110 comprises a plurality of first plates 112 in communication or joined (e.g., side-by-side or laterally) with one another along with their respective second plates 111 on the back side with a core 114 disposed there between.
Further, during assembly of any of the components related with the JBD system a variety of welding or joining techniques may be applied, including, but not limited thereto, friction stir welding for effective joining. Some of the joints, particularly “lap joints” provide open paths to bare aluminum (or desired or required material) of the plates or cores (for example), which in turn may produce undesirable corrosion product in certain instances. To prevent this, optionally special sealants may be employed which are applied during welding (e.g., friction stir welding or as desired or required) to those lap joints.
FIGS. 12 (A)-(C) are schematic illustration of an embodiment of a sandwich structure 1201 demonstrating blast or explosion mitigation in response to an explosion. FIGS. 12 (A)-(C) provide the impulse loading stage, core crushing stage, and panel bending stage, respectively.
FIGS. 13 (A)-(D) are schematic illustration of an embodiment of a sandwich structure 1301 demonstrating projectile arresting capabilities in response to a projectile, which provides various rupture and fracture details. As shown inserts 1305 (e.g., prism shaped) are disposed therein and filler material 1303 (e.g., elastomers) in the interstial space of the sandwich structure 1301 .
REFERENCES CITED
The following patents, applications and publications as listed below and throughout this document are hereby incorporated by reference in their entirety herein. The devices, systems, articles of manufacture and methods of various embodiments of the present invention disclosed herein may utilize aspects disclosed in the following patents and applications and are hereby incorporated by reference in their entirety:
PCT International Application No. PCT/US02/17942, entitled “Multifunctional Periodic Cellular Solids And The Method of Making Thereof,” filed Jun. 6, 2002, and corresponding U.S. application Ser. No. 10/479,833, entitled “Multifunctional Periodic Cellular Solids And The Method of Making Thereof,” filed on Dec. 5, 2003. PCT International Application No. PCT/US03/16844, entitled “Method for Manufacture of Periodic Cellular Structure and Resulting Periodic Cellular Structure,” filed May 29, 2003, and corresponding U.S. application Ser. No. 10/515,572, entitled “Multifunctional Periodic Cellular Solids And The Method of Making Thereof,” filed Nov. 23, 2004. PCT International Application No. PCT/US04/04608, entitled “Methods for Manufacture of Multilayered Multifunctional Truss Structures and Related Structures There from,” filed Feb. 17, 2004, and corresponding U.S. application Ser. No. 10/545,042, entitled “Methods for Manufacture of Multilayered Multifunctional Truss Structures and Related Structures There from,” filed Aug. 11, 2005. PCT International Application No. PCT/US01/22266, entitled “Method and Apparatus For Heat Exchange Using Hollow Foams and Interconnected Networks and Method of Making the Same,” filed Jul. 16, 2001, and corresponding U.S. application Ser. No. 10/333,004, entitled “Heat Exchange Foam,” filed Jan. 14, 2003. PCT International Application No. PCT/US01/25158 entitled “Multifunctional Battery and Method of Making the Same”, filed Aug. 10, 2001, and corresponding U.S. application Ser. Nos. 10/110,368, entitled “Multifunctional Battery and Method of Making the Same”, filed Jul. 22, 2002, and 11/788,958, entitled “Multifunctional Battery and Method of Making the Same”, filed Apr. 23, 2007. PCT International Application No. PCT/US03/27606, entitled “Method for Manufacture of Truss Core Sandwich Structures and Related Structures Thereof,” filed Sep. 3, 2003, and corresponding U.S. application Ser. No. 10/526,296, entitled “Method for Manufacture of Truss Core Sandwich Structures and Related Structures Thereof,” filed Mar. 1, 2005. PCT International Application No. PCT/US01/17363, entitled “Multifunctional Periodic Cellular Solids And The Method of Making Thereof,” filed May 29, 2001, and corresponding U.S. application Ser. No. 10/296,728, entitled “Multifunctional Periodic Cellular Solids And The Method of Making Thereof,” filed Nov. 25, 2002. PCT International Application No. PCT/US2007/012268, entitled “Method and Apparatus for Jet Blast Deflection”, filed May 23, 2007 and corresponding U.S. application Ser. No. 12/301,916, entitled “Method and Apparatus for Jet Blast Deflection,” filed Nov. 21, 2008. ASTM. C273 Standard Test Method for Shear Properties of Sandwich Core Materials. West Conshohocken, Pa., USA: ASTM International, 2006. ASTM. C365 Standard Test Method for Flatwise Compressive Properties of Sandwich Cores. West Conshohocken, Pa., USA: ASTM International, 2006. ASTM. E8 Standard Test Methods for Tension Testing of Metallic Materials. West Conshohocken, Pa., USA: ASTM International, 2006. Bitzer, T. 1997 Honeycomb technology. London: Chapman & Hall. Chiras, S., Mumm, D. R., Evans, A. G., Wicks, N., Hutchinson, J. W., Dharmasena, K. P., Wadley, H. N. G. and Fichter, S., 2002. The structural performance of near-optimized truss core panels. International Journal Solids and Structures, 39 (15) 4093-4115. Cote, F., Deshpande, V. S. and Fleck, N. A., Shear fatigue strength of a prismatic diamond sandwich core. Scripta Materialia 2007; 56:585-588. Cote, F., Fleck, N. A. and Deshpande, V. S., Fatigue performance of sandwich beams with a pyramidal core. International Journal of Fatigue 2007; 29:1402-1412. Deshpande, V. S., Fleck, N. A. and Ashby, M. F., 2001. Effective properties of the octet-truss lattice material. Journal of the Mechanics and Physics of Solids, 49 (8), 1747-1769. Deshpande, V. S. and Fleck, N. A., 2001. Collapse of truss core sandwich beams in 3-point bending. International Journal of Solids and Structures, 38 (36-37), 6275-6305. Evans, A. G., Hutchinson, J. W. and Ashby, M. F., Cellular metals. Current. Opinion in Solid State and Materials Science 1998; 3:288-303. Evans, A. G., Hutchinson, J. W., Fleck, N. A., Ashby, M. F. and Wadley, H. N. G., The topological design of multifunctional cellular metals. Progress in Materials Science 2001; 46:309-327. Gibson, L. J. and Ashby M F. Cellular Solids, Structure and Properties. Cambridge: Cambridge University Press, 1997. Kooistra, G. W., Aluminum alloy lattice truss structures. Materials Science & Engineering, M.S. Charlottesville: University of Virginia, 2006. Kooistra, G. W., Queheillalt D. T. and Wadley H. N. G., Shear behavior of aluminum lattice truss sandwich panel structures. Materials Science and Engineering A 2007; In Press. Lim, J. H. and Kang, K. J., 2006. Mechanical behavior of sandwich panels with tetrahedral and Kagome truss cores fabricated from wires. International Journal of Solids and Structures, 43 (17), 5228-5246. McShane, G. J., Radford, D. D., Deshpande V. S. and Fleck, N. A., 2006. The response of clamped sandwich plates with lattice cores subjected to shock loading. European Journal of Mechanics—A/Solids, 25 (2), 215-229. Queheillalt, D. T. and Wadley, H. N. G., 2005. Pyramidal lattice truss structures with hollow trusses. Materials Science and Engineering A, 397 (1-2), 132-137. Queheillalt, D. T. and Wadley, H. N. G., Titanium Alloy Lattice Truss Structures. Materials and Design 2007:Submitted March 2007. Radford, D. D., Fleck N. A. and Deshpande, V. S., 2006. The response of clamped sandwich beams subjected to shock loading. International Journal of Impact Engineering, 32 (6), 968-987. Rathbun, H. J., Wei, Z., He, M. Y., Zok, F. W., Evans, A. G., Sypeck, D. J. and Wadley, H. N. G., 2004. Measurement and Simulation of the Performance of a Lightweight Metallic Sandwich Structure with a Tetrahedral Truss Core. Journal of Applied Mechanics, 71 (3), 305-435. Sugimura, Y., 2004. Mechanical response of single-layer tetrahedral trusses under shear loading. Mechanics of Materials, 36 (8), 715-721. Sypeck, D. J. and Wadley, H. N. G., 2002. Cellular metal truss core sandwich structures. Advanced Engineering Materials, 4 (10), 759-764. Wadley, H. N. G., Multifunctional periodic cellular metals. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 2006; 364:31-68. Wadley, H. N. G., Fleck, N. A. and Evans, A. G., Fabrication and structural performance of periodic cellular metal sandwich structures. Composites Science and Technology 2003; 63:2331-2343. Wallach, J. C. and Gibson, L. J., 2001. Mechanical behavior of a three-dimensional truss material. International Journal of Solids and Structures, 38 (40-41), 7181-7196. Wang, J., Evans, A. G., Dharmasena, K. and Wadley, H. N. G., 2003. On the performance of truss panels with Kagomé cores. International Journal of Solids and Structures 40 (25), 6981-6988. Zhou, J., Shrotiriya, P. and Soboyejo, W. O., 2004. On the deformation of aluminum lattice block structures from struts to structure. Mechanics of Materials, 36 (8), 723-737. Zok, F. W., Waltner, S. A., Wei, Z., Rathbun, H. J., McMeeking, R. M. and Evans, A. G., 2004. A protocol for characterizing the structural performance of metallic sandwich panels: application to pyramidal truss cores. International Journal of Solids and Structures 41 (22-23) 6249-6271.
In summary, while the present invention has been described with respect to specific embodiments, many modifications, variations, alterations, substitutions, and equivalents will be apparent to those skilled in the art. The present invention is not to be limited in scope by the specific embodiment described herein. Indeed, various modifications of the present invention, in addition to those described herein, will be apparent to those of skill in the art from the foregoing description and accompanying drawings. Accordingly, the invention is to be considered as limited only by the spirit and scope of the following claims, including all modifications and equivalents.
Still other embodiments will become readily apparent to those skilled in this art from reading the above-recited detailed description and drawings of certain exemplary embodiments. It should be understood that numerous variations, modifications, and additional embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of this application. For example, regardless of the content of any portion (e.g., title, field, background, summary, abstract, drawing figure, etc.) of this application, unless clearly specified to the contrary, there is no requirement for the inclusion in any claim herein or of any application claiming priority hereto of any particular described or illustrated activity or element, any particular sequence of such activities, or any particular interrelationship of such elements. Moreover, any activity can be repeated, any activity can be performed by multiple entities, and/or any element can be duplicated. Further, any activity or element can be excluded, the sequence of activities can vary, and/or the interrelationship of elements can vary. Unless clearly specified to the contrary, there is no requirement for any particular described or illustrated activity or element, any particular sequence or such activities, any particular size, speed, material, dimension or frequency, or any particularly interrelationship of such elements. Accordingly, the descriptions and drawings are to be regarded as illustrative in nature, and not as restrictive. Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. When any range is described herein, unless clearly stated otherwise, that range includes all values therein and all sub ranges therein. Any information in any material (e.g., a United States/foreign patent, United States/foreign patent application, book, article, etc.) that has been incorporated by reference herein, is only incorporated by reference to the extent that no conflict exists between such information and the other statements and drawings set forth herein. In the event of such conflict, including a conflict that would render invalid any claim herein or seeking priority hereto, then any such conflicting information in such incorporated by reference material is specifically not incorporated by reference herein.
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Methods and systems to manufacture lattice-based sandwich structures from monolithic material. Such methods and systems eliminate the bonding process which is conventionally used to join lattice based truss cores to facesheets to form sandwich structures. This bonded interface is a key mode of failure for sandwich structures which are subjected to shear or bending loads because the nodes transfer forces from the face sheets to the core members while the topology for a given core relative density dictates the load carrying capacity (assuming adequate node-bond strength exists). An aspect comprises a core and related structures that provide very low density, good crush resistance and high in-plane shear resistance. An aspect of the truss structures may include sandwich panel cores and lattice truss topology that may be designed to efficiently support panel bending loads while maintaining an open topology that facilitates multifunctional applications.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 08/599,364 filed Mar. 11, 1996 now U.S. Pat. No. 5,631,000 and entitled Anhydrous Tooth Whitening Gel.
FIELD OF THE INVENTION
This invention relates to dental compositions and, more particularly, to stabilized anhydrous tooth whitening gel compositions, a method for preparing the gel compositions, and a method for utilizing the gel compositions.
PRIOR ART
In that aspect of aesthetic dentistry which relates to self-administered use of in-home tooth whitening compositions, the dental patient is provided with a custom-fitted dental tray having selectively enlarged tooth treating compartments which are adapted to receive a whitening gel that is dispensed from a syringe. The dental tray, with its gel content, is unobtrusively and advantageously worn by the patient at night and while the patient sleeps. This treatment is repeated for a sufficient period of time to effect the tooth bleaching and whitening process.
It is disclosed in the prior art that carboxypolymethylene as well as methylcelluose can be used as the gelation agents in the formulation of tooth whitening gels. The prior art also discloses that carbamide peroxide (urea peroxide) as well as hydrogen peroxide can be used as the whitening agents in the formulation of tooth whitening gels.
U.S. Pat. No. 5,290,566 (Schow, et al., 1994) discloses a tooth whitening gel containing urea peroxide (carbamide peroxide), methylcelluose and water wherein the concentration of urea peroxide is from about 22 to about 32 wt. %.
U.S. Pat. Nos. 5,098,303 (Fischer, 1992), 5,234,342 (Fischer, 1993), 5,376,006 (Fischer, 1994) and 5,409,631 (Fischer, 1995), which are incorporated herein by reference, disclose tooth bleaching and whitening gel compositions formulated with carbamide peroxide, water, glycerin, carboxypolymethylene and sodium hydroxide. With respect to broad range ingredient concentration, the formulations contain from about 3.0 to about 20 wt. % carbamide peroxide, from about 10 to about 60 wt. % water, from about 20 to about 70 wt. % glycerin, from about 3.5 to about 12 wt. % carboxypolymethylene and sodium hydroxide in an amount to substantially neutralize the carboxypolymethylene. The gel is characterized as comprising a saturated or super saturated carboxypolymethylene composition wherein the actual concentration of carboxypolymethylene in the total quantity of water in the gel composition is in the range from about 15% to about 40%, with the concentrated carboxypolymethylene providing the gel composition with a tackiness or stickiness. As to gel preparation, the patentee recommends that the carboxypolymethylene be mixed with glycerin and the resulting admixture dispersed in water, followed by the addition of the remaining ingredients, namely, sodium hydroxide and carbamide peroxide.
It has been observed that carbamide peroxide tooth whitening gels containing relatively high concentrations of water, glycerin and carboxypolymethylene (a) tend to have limited package stability as a result of the interaction of carbamide peroxide with water, (b) tend to increase tooth sensitivity as a result of the hygroscopic properties of glycerin which can reduce the moisture level at the tooth treatment surface, and (c) tend to string from one tooth treating compartment in the bleaching tray to the next tooth treating compartment in the tray in the course of syringe loading the compartments with the bleaching gel.
Although the foregoing limitations have been addressed by the development and use of anhydrous tooth whitening gels, it has now been observed that tooth whitening gels formulated with thickeners such as carboxypolymethylene and/or cellulosics exemplified by carboxymethylcullulose, hydroxymethylcellulose and hydroxypropylcellulose tend to decrease in viscosity with an increase in temperature. During overnight oral application of the tooth whitening gel, the temperature of the gel in the dental tray can increase from ambient to about 37° C. (98.6° F.). As a result of this rise in temperature, the gel tends to thin and become somewhat flowable. If the gel gets too thin, it may flow out of the tray and into contact with the soft tissue, causing tissue irritation.
SUMMARY OF THE INVENTION
An important object of the present invention is to provide new and improved dental whitening compositions which address the viscosity limitations of the prior art tooth whitening gels as hereinabove described.
Another object of this invention is to provide tooth whitening gel compositions which enable a reduced concentration of carboxypypolmythylene to be used as a thickener without impairing the requisite viscosity characteristics of the gel compositions during oral use.
A further object of this invention is to provide tooth whitening gel compositions which resist viscosity degradation during oral use.
An additional object of this invention is to provide tooth whitening gel compositions which retain their viscosity in the presence of an increase in temperature and a decrease in pH that are encountered during oral use.
These and other objects and features of the present invention are accomplished with the compositions, methods and procedures as described herein.
In accordance with one aspect of this invention, there is provided a tooth whitening composition containing carbamide peroxide dispersed in a substantially anhydrous gelatinous carrier. The anhydrous carrier comprises a polyol component wherein glycerin, if present, is limited to an amount that does not exceed about 10 wt. % based on the total weight of the composition. The anhydrous carrier also comprises a thickener component containing neutralized carboxypolymethylene, cellulosic ether soluble in the polyol component and a viscosity stabilizer comprising xanthan gum.
In accordance with a second aspect of this invention, there is provided a method for whitening teeth which comprises (1) extruding a substantially anhydrous tooth whitening gel composition into the reservoir system of a dental bleaching tray, (2) placing the dental tray in the oral cavity so as to bring the gel composition into contact with the teeth to be whitened, (3) maintaining the gel composition in contact with the aforesaid teeth for a plurality of hours per day, and (4) repeating steps 1, 2 and 3 for multiple days to effect whitening of the teeth. The anhydrous tooth whitening gel composition which can be used in carrying out the method advantageously comprises (a) propylene glycol in an amount from about 10 wt. % to about 50 wt. %, (b) polyethylene glycol in an amount from about 10 wt. % to about 55 wt. %, and having a molecular weight from about 400 to about 1500, (c) glycerin in an amount from about 0 wt. % to about 10 wt. %, (d) carboxypolymethylene in an amount from about 0.5 wt. % to about 3.0 wt. %, (e) hydroxypropylcellulose in an amount from about 0.5 wt. % to about 10 wt. %, (f) xanthan gum in an amount from about 0.1 wt % to about 1.5 wt. %, (g) neutralizing reagent in an amount to substantially neutralize carboxypolymethylene, and (g) carbamide peroxide in an amount from about 5.0 wt. % to about 25 wt. %.
In accordance with a third aspect of this invention, there is provided a method for preparing substantially anhydrous dental whitening gel compositions. The method comprises admixing a settable ingredient mix to obtain a homogenous dispersion of the ingredients. The settable ingredient mix advantageously comprises (a) propylene glycol in an amount from about 10 wt. % to about 55 wt. %, (b) polyethylene glycol in an amount from about 10 wt. % to about 50 wt. %, and having a molecular weight from about 400 to about 1500, (c) glycerin in an amount from about 0 wt. % to about 10 wt. %, (d) carboxypolymethylene in an amount from about 0.5 wt. % to about 3.0 wt. %, (e) hydroxypropylcellulose in an amount from about 0.5 wt. % to about 10 wt. %, (f) xanthan gum in an amount from about 0.1 wt % to about 1.5 wt. %, (g) neutralizing reagent in an amount to substantially neutralize carboxypolymethylene, and (h) carbamide peroxide in an amount from about 5.0 wt. % to about 25 wt. %, (i) wherein weight percent is based on the total weight of the gel composition.
DETAILED DESCRIPTION
The dental whitening gel compositions of this invention comprise carbamide peroxide dispersed in an anhydrous gelatinous carrier. Carbamide peroxide is generally present in the anhydrous gel compositions in an amount from about 5 wt. % to about 25 wt. % and, preferably, in an amount from about 10 wt. % to about 20 wt. %.
The anhydrous gelatinous carrier comprises a liquid component and a thickener component. Liquid polyols such as propylene glycol and polyethylene glycol are advantageously used in formulating the liquid component. Propylene glycol is generally present in the gel compositions in an amount from about 10 wt. % to about 55 wt. % and, preferably, in an amount from about 25 wt. % to about 45 wt. %. Polyethylene glycol which can be used in the practice of this invention has a molecular weight from about 400 to about 1500 and is generally present in the gel compositions in an amount from about 10 wt. % to about 50 wt. % and, preferably, in an amount from about 25 wt. % to about 45 wt. %.
Glycerin can also be used as a constituent of the liquid component. However, glycerin is hygroscopic and a high concentration of glycerine in the gel tends to pull moisture away from the surface of the teeth which can lead to increased dental sensitivity to the bleaching composition. Accordingly, if glycerin is used in the bleaching gel, it should be limited to a concentration that does not exceed about 10 wt. % of the gel composition. In a more specific aspect, glycerin can be present in the gel composition in an amount from about 3.0 wt. % to about 9.0 wt. %.
The thickener portion of the gel composition advantageously contains a blend of neutralized carboxypolymethylene and cellulosic ether that is soluble in the liquid component. Carboxypolymethylene is generally present in the gel compositions in an amount from about 0.5 wt. % to about 3.0 wt. % and, preferably, in an amount from about 1.5 wt. % to about 2.5 wt. %. Carboxypolymethylene is characterized as a slightly acidic vinyl polymer with active carboxyl groups. Typically, the acidic carboxypolymethylene is neutralized in situ during the preparation of the gel composition by adding an anhydrous alkalinizing agent such as anhydrous sodium hydroxide to the pre-gelatinous mix in order to bring the pH of the gel composition to an orally acceptable level as, for example, a pH from about 6.0 to about 7.5.
Cellulosic ether is generally present in the gel compositions in an amount from about 0.5 wt. % to about 10 wt. % and, preferably, in an amount from about 1.0 wt. % to about 3.0 wt. %. A preferred cellulosic ether is hydroxypropylcellulose.
The blend of neutralized carboxypolymethylene and cellulosic ether is particularly advantageous because the blend provides the gel compositions with improved thixotropic properties in respect of flow-set characteristics. This rheological enhancement constitutes an improvement in the dental whitening art because it tends to minimize the stringing and roping of the gel from one tooth treating compartment to the next tooth treating compartment during the sequential syringe loading of the gel into the compartments of the dental whitening tray.
Xanthan gum is generally present in the gel compositions in an amount from about 0.1 wt. % to about 1.5 wt. % and, preferably, in an amount from about 0.3 wt. % to about 1.3 wt. %. Xanthan gum, (Merck Index No. 10191, 12th ed.), is available under the trademark Keltrol. Xanthan gum is prescribed as an exocellular heteropolysaccharide produced via a closely controlled fermentation of the bacteria Xanthamonas campestries and its structure is characterized as a cellulose backbone with trisaccharide side claims in alternating anhydroglucose units consisting of a glucuronic acid residue between two mannose units wherein the molecule exists as a right-handed, fivefold helix with the trisaccharide side claims effectively shielding the backbone.
The anhydrous tooth whitening gels of this invention are prepared by adding and mixing the ingredients of the formulation in a suitable vessel such as a stainless steel tank that is provided with a heavy duty mixer which is suitable for use with thick gels. If desired, the mixing vessel can be combined with vacuum equipment for carrying out the admixing of the ingredients under vacuum conditions. The ingredients of the formulation are mixed to obtain a homogenous dispersion which sets to a thixotropic gel.
In the preparation of the dental whitening gels, the formulating ingredients are advantageously added to the mixing vessel in the following order: liquid ingredients, thickener ingredients, alkalinizing agent, carbamide peroxide, and any desired flavoring.
The quantities of the formulating ingredients are so selected as to provide the whitening gels with a composition containing (a) propylene glycol in an amount from about 10 wt. % to about 55 wt. % and, preferably, in an amount from about 25 wt % to about 45 wt. %, (b) polyethylene glycol in an amount from about 10 wt. % to about 50 wt. % and, preferably, in am amount from about 25 wt. % to about 45 wt. % and having a molecular weight from about 400 to about 1500, (c) glycerin in an amount from about 0 wt. % to about 10 wt. % and, preferably, in an amount from about 3.0 wt. % to about 9.0 wt. %, (d) carboxypolymethylene in an amount from about 0.5 wt. % to about 3.0 wt. % and, preferably, in an amount from about 1.5 wt. % to about 2.5 wt. %, (e) hydroxypropylcellulose in an amount from about 0.5 wt. % to about 10 wt. % and, preferably, in an amount from about 1.0 wt. % to about 3.0 wt. % (f) xanthan gum in an amount from about 0.1 wt. % to about 1.5 wt. % and, preferably, in an amount from about 0.3 wt. % to about 1.3 wt. %, (g) neutralizing reagent, preferably, anhydrous sodium hydroxide in an amount to substantially neutralize carboxypolymethylene, and (h) carbamide peroxide in an amount from about 5.0 wt. % to about 25 wt. % and, preferably, in an amount from about 10 wt. % to about 20 wt. %.
EXAMPLES
The following examples further illustrate the anhydrous tooth whitening gels of this invention and the concentration ranges for the ingredients thereof. As used in the examples, "PEG" is a trade designation for polyethylene glycol (Merck Index No. 7545, 11th ed.), "Carbopol" is a trademark for carboxypolymethylene (Merck Index No. 1836, 11th ed.) and "Klucel" is a trademark for hydroxypropylcellulose (Merck Index No. 4776, 11th ed.). The bleaching gels were prepared in accordance with the method and procedure as hereinabove described.
______________________________________ Weight PercentIngredients Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5______________________________________Propylene glycol 47.4 49.0 45.4 43.4 48.4PEG 600 20.0 21.7 -- 16.0 15.0PEG 1000 10.0 11.7 -- -- 15.0PEG 1450 -- -- 26.0 6.0 --PEG 1500 -- -- -- -- --Glycerin 8.0 8.0 8.0 8.0 7.0Carbopol 980 2.2 2.2 2.2 2.2 2.2Klucel GFF 1.7 1.5 1.0 0.8 1.3Xanthan gum 0.1 0.3 0.8 1.0 1.3Flavor 0.2 0.2 0.2 0.2 0.2Sodium hydroxide 0.4 0.4 0.4 0.4 0.4Carbamide peroxide 10.0 5.0 16.0 22.0 10.0 100.0 100.0 100.0 100.0 100.0______________________________________ Weight PercentIngredients Ex. 6 Ex. 7 Ex. 8 Ex. 9______________________________________Propylene glycol 46.4 45.4 54.2 41.1PEG 600 -- -- 28.0 --PEG 1000 31.0 16.0 -- --PEG 1450 -- 16.0 -- --PEG 1500 -- -- -- 35.2Glycerin 8.0 8.0 3.0 3.0Carbopol 980 2.1 2.0 0.5 2.0Xanthan gum 0.1 0.2 1.5 1.0Klucel GFF 1.8 1.8 0.4 1.0Klucel MFF -- -- 0.8 --Flavor 0.2 0.2 0.2 0.2Sodium hydroxide 0.4 0.4 0.4 0.5Carbamide peroxide 10.0 10.0 11.0 16.0 100.0 100.0 100.0 100.0______________________________________
The anhydrous tooth whitening gel compositions, as hereinabove described, are packaged in appropriate syringes for dispensing into custom-fitted dental trays that are usually worn at night, but can also be worn during the day, with maximum whitening generally occurring when the treatment is continued for ten to fourteen days. The custom-fitted dental bleaching trays can be prepared by using materials and procedures that are well known in the dental art, and which are described in the prior art cited herein.
In a first alternative packaging embodiment, the dental whitening gels can be packaged in gel dispensing tubes or bottles for extrusion into general purpose dental trays for carrying out the dental whitening process. In a second alternative packaging embodiment, pre-packaged dental trays can be provided to the user containing dental whitening gels which have been adapted for this purpose.
In view of the foregoing descriptions and examples, it will become apparent to those of ordinary skill in the art that equivalent modifications thereof may be made without departing from the spirit and scope of this invention.
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Stabilized anhydrous dental whitening gel compositions are provided which resist viscosity degradation during oral use. An illustrative anhydrous dental bleaching gel composition embodying this feature comprises propylene glycol, polyethylene glycol, glycerin in an amount not exceeding about 10 wt. %, neutralized carboxypolymethylene, hydroxypropylcellulose, xanthan gum and carbamide peroxide.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional application Ser. No. 60/052,004, filed Jul. 9, 1997.
BACKGROUND OF THE INVENTION
1. Technical Field
The invention relates to roofing structures for buildings and more particularly to metal deck roof structures having an overlay of a meltable insulation material. Even more particularly the invention relates to such a roofing structure which seals openings formed at the junctions of the overlapping metal sheets and provides both a thermal and physical barrier preventing the insulation material upon becoming liquid during a fire, from leaking into the building below.
2. Background Information
Roofing systems for commercial and industrial buildings utilize various types of sheet metal panels which are laid in an overlapping relationship and secured to a lower structured frame of a roof deck. An insulation layer is laid on top of the metal sheets which is then covered by a waterproof material, one common type of which is EPDM, together with a ballast or other hold down system. One type of insulation material is a polystyrene foam which is expanded or extruded, usually in sheets, which provide the desired insulating qualities as well as being lightweight thereby contributing very little to the overall weight load of the roof.
However, one problem with the use of such foam insulation in roofing structures is that the foam can melt and burn when the building experiences a fire, and more importantly becomes liquid with the resulting molten liquid flowing through the joints of the roof deck into the building interior below increasing the hazard to occupants as well as to the safety forces during a fire. These metal roof deck sheets are usually fluted with peaks and valleys, with the overlying joint formed between adjacent panels, which usually occurs in a valley, which makes the joint opening very susceptible to the molten liquid flowing through the joint opening and other openings in the steel deck and into the building below. Various systems have been devised to provide an effective seal to metal roof decks, either to prevent the flow of water or other liquid through the joints and panel openings and into the building interior.
U.S. Pat. Nos. 2,106,390 and 2,616,283 disclose roof structures in which the flutes of the metal decks are filled with a granular material. However, this filling material hardens and is used to provide the attachment means for receiving nails or other fasteners for securing the insulation on the top of the metal sheets and not for sealing the overlap joint of adjacent roof deck sheeting.
U.S. Pat. No. 4,936,071 discloses a metal roof wherein the joints are sealed with a tape laminate formed of an unvulcanized EPDM and butyl rubber to provide for a waterproof seal at the overlapping joints.
U.S. Pat. No. 5,392,583 discloses another metal roof installation using flexible elongated elastic strips for sealing the overlapping joints.
U.S. Pat. No. 5,479,753 discloses a metal roof in which an elongated strip of flexible hot melt thermoplastic bituminous composite material is placed over the overlapping joints or seams and heated to bond the strip to the metal roof to provide a weather proof seal therebetween.
U.S. Pat. Nos. 3,763,614 and 4,449,336 disclose other metal roofing structures using various types of barriers between the insulation and the roof deck for reducing the harmful affect should the building experience a fire.
U.S. Pat. No. 4,747,247 discloses a roof system in which the troughs or valleys of the metal sheets are filled with various nonflammable loose packed granular inorganic material which is intended to absorb the molten liquid resulting from the insulation sheets during a fire. However, a major draw back of this type of system is that it adds considerable weight to the building since nearly every trough or valley must be filled with this loose packed granular material. Even if a light weight granular material is used, the weight required to be supported by the underlying roof deck is increased considerably due to the vast amount of material that is required to fill the valleys and troughs in order to absorb the heated liquid material.
U.S. Pat. No. 3,511,007 discloses still another metal roofing structure in which a closed cell non-absorbent foam material is sprayed on the edge of the metal roof sheet, individually or in combination with a breaker strip, for bonding to the undersurface of the adjacent metal sheet edge when it is placed thereon to provide a waterproof seal at the joint formed by the overlapping metal panel edges.
Although these various roof systems achieve certain desired results, in many instances they either materially increase the weight that must be supported by the roof, or are expensive and time consuming to install due to the amount of material required and the labor cost to install the same.
Therefore the need exists for an improved method and roof sealing system which does not materially increase the weight of the roof and which is inexpensive and easy to install, yet provides for the desired fire resistant liquid seal between overlapping joints of adjacent metal panels to prevent the molten liquid formed by the overlying insulation during a fire from flowing into the building below.
SUMMARY OF THE INVENTION
Objectives of the invention include providing a metal roof sealing system and method having a plurality of overlapping fluted metal sheets covered with a meltable insulation layer for supporting an overlying waterproof membrane and hold down means, wherein the openings formed at the overlapping joints of the metal sheets are sealed with a sealing compound such as polyurethane foam and/or a type of cementitious material which forms both a thermal and physical barrier to the passage of molten material.
A further objective of the invention is to provide such a roofing system in which the overlapping metal sheets or metal plates are sealed both along the overlapping side edge joint and also along the end edge joints by the sealing material.
A still further objective of the invention is to provide such a roof sealing system in which the cementitious material may be a common mortar, gypsum plaster, Portland cement and sand, etc. which when applied is in a paste or slurry form and then hardens to form the sealing bead or strip which extends along the overlapping joint, usually in the bottom of a trough or valley of the fluted metal sheets.
Another objective of the invention is to provide such roof sealing system in which a polyurethane sealing foam is applied in a liquid or slurry state and quickly turns into a solid to form an effective thermal liquid proof barrier for the steel deck joints.
Still another objective of the invention to provide such a roof sealing system in which the sealing material needs to be applied only at the joints or other openings in the metal deck, such as around vent ducts or the like, eliminating its use in the other troughs or valleys of the fluted metal sheets, thereby reducing the weight required to be supported by the underlying roof structure and reducing the amount of materials and associated costs of applying the same.
A further objective of the invention is to provide such a roof sealing system in which the sealing of the joints materially reduces the amount of melted insulation material which drops into the space below thereby removing material which heretofore is ignited by the existing fire.
These objectives and advantages are obtained by the improved metal roofing system of the invention the general nature of which may be stated as including a plurality of sheet metal panels attached to a structure of a building and forming seams at the junctions with adjacent panels; and in which a nonflammable or low combustible, char-forming, nonabsorbent layer of an applied-in-place sealing material is applied in a liquid or slurry form along the seams and upon hardening forms a thermal liquid proof barrier for the seam.
These objectives and advantages are further obtained by the improved method of fabricating a roof system, the general nature of which may be stated as including the steps of providing a supporting roof deck; securing a plurality of overlapping sheet metal panels to the roof deck thereby forming seams at junctions with adjacent overlapped panels, said panels having alternating grooves and ridges; placing a nonflammable or low combustible, char-forming, nonabsorbent layer of sealing material in a slurry form along certain of the seams; permitting said slurry to harden to form a thermal and liquid barrier over said certain seams; placing a plurality of thermoplastic insulation panels on the ridges of said metal panels; placing a waterproof membrane over the insulation panels; and securing said membrane to said roof deck.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention illustrative of the best mode in which applicants have contemplated applying the principles is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appendant claims.
FIG. 1 is a diagrammatic perspective view with portions broken away and in section, of a metal roof incorporating the improved sealing system therein;
FIG. 2 is an enlarged fragmentary sectional view showing the seam opening formed at the junction of a pair of adjacent roof panels prior to placement of the sealing strip thereon;
FIG. 3 is an enlarged fragmentary sectional view similar to FIG. 2, showing the sealing seam being formed of a cementitious material;
FIG. 4 is an enlarged fragmentary sectional view similar to FIGS. 2 and 3, showing the seam formed of a polyurethane foam;
FIG. 5 is a chart showing the rate of heat release in a test fire when the metal roof joints are not sealed in accordance with the present invention; and
FIG. 6 is a chart showing the heat release rate in a similar test fire represented in FIG. 5 utilizing the sealing system of the present invention.
Similar numerals refer to similar parts throughout the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The improved metal roof system of the present invention is indicated generally at 1, and is shown in a generally diagrammatic fragmentary sectional breakaway view in FIG. 1. Roof system 1 includes a structural frame of the roof deck, which as shown in the drawing consists of a plurality of spaced I-beams 2, which could be other types of roof deck supports, such as bar joists, wooden or metal pylons or the like.
A plurality of generally similar sheet metal panels, each of which is indicated generally at 4, are mounted on and secured to beams 2 by plurality of fasteners 5 such as nails, screws, by welding or other attachment means. Each panel 4 is formed by a plurality of alternating flutes or grooves 6 and intervening ridges 7 and have top and bottom surfaces 9 and 9A respectively. Adjacent panels 4 have their terminal longitudinally extending ends 8 overlapped by the inmost ridge of adjacent panels as shown particularly in FIG. 2. The adjacent panels are secured to each other usually in the flutes or valleys 6 by spot welds or by a plurality of sheet metal screws or other fasteners. This overlapping relationship forms a longitudinally extending seam 10, which due to manufacturing tolerances and irregularities in the roof deck, will usually result in an opening 12 formed at seam 10. Also the transverse ends 13 of adjacent panels are overlapped, as shown in FIG. 1 forming a seam 14 which extends transversely to the longitudinal direction of the flutes and ridges of each panel. This seam will also result in an elongated transverse opening 16 through which water and molten liquid insulation can flow through and into the building below.
Roof system 1 further includes a plurality of sheets or panels of insulation 17 such as polystyrene, which are loose-laid or secured to ridges 7 of panels 4 by usual attachment means and extend generally throughout the entire area of the roof. Next, a layer of a waterproof membrane 18, such as EPDM, extends across and can be secured to insulation panels 17 by well known fastening means, or a layer of a ballast 19, such as gravel, is then applied to keep membrane 18 in position. Other types of membrane retaining means other than ballast 19 can be used without affecting the concept of the invention.
In accordance with the invention, a bead or strip of a flame retardant waterproof barrier 20 is applied along both the longitudinal and transverse seams 10 and 14, respectively, as shown generally in FIG. 1 and in detail in FIGS. 3 and 4, to seal openings 12 and 16, and at other openings such as around vents, ducts, skylights, etc.
In a first embodiment as shown in FIG. 3, sealant strip 20 is a cementitious material such as gypsum plaster with or without a vermiculite, a common mortar, such as Portland cement and sand. The advantage of this type of material is that upon setting there is very little (a slight contraction) dimensional change, which is important in this application. Different types of plasters are made which vary in the time taken to set, the amount of water to make a pourable material and the hardness. These characteristics are controlled by the calcination conditions and by addition of other materials (organic and inorganic) to the plaster. Mortar is mixture of solids and water used to generally bond masonry units together. The principal solids in mortar are sand and cementitious materials, such as hydrated lime, (or slaked quicklime) and Portland cement. The definition of portland cement is given in ASTM C 150 as a hydraulic cement produced by pulverizing clinkers consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an interground addition. The definition of hydraulic cements is that they harden by reacting with water to form a water-resistant product. Gypsum will dissolve in water after it is hardened and is therefore not as useful a portland cement in many application. There are many other cementitious materials, but none is more important than portland cement. The latter is absent in pure lime mortar. Portland cement reacts rapidly with water, which gives the mortar its initial set. Lime react more slowly, both with carbon dioxide from the atmosphere to form calcium carbonate and with sand to form calcium silicates. Thus, mortar hardens with age and has good workability. Again, variations in composition can effect how flowable the mortar is and how fast it hardens. Organic and inorganic materials including organic plastics can be added to the mortar to improve performance.
FIG. 4 shows a modified form of sealant strip 23 which is a polyurethane foam having a flame retardant of approximately 100 parts per hundred parts polyol, and with an index up to 250. Other examples of flame retardants can be antimony oxide, calcium carbonate, and pentabromodiphenyl oxide. The use of sucrose and/or aromatic polyols (Hoechst Celanese's Terate 2541 (aromatic polyester polyol) and Dow's Voranol 490 (sucrose based)) which forms a protective char layer during a fire is highly resistant to further combustion. The corresponding polyurethane foam has a density of approximately 1 to 6 pounds per cubic feet.
Sealant strips 20 and 23 provide a physical barrier to the flow of molten thermoplastic material which results when insulation panels 17 are subjected to very high temperatures, such as in a fire. This molten thermoplastic material is prevented by strips 20 and 23 from flowing through openings 12 and 16 and into the building below through the space normally present between the overlapped roof deck panels. Various sealant strips 20 and 23 will be fire resistant and/or char forming and are able adhere to the sheet metal panels 4, and turn into a solid from a liquid or slurry state relatively quickly when applied thereto.
The method of the present invention is best understood by reference to FIG. 1 which shows the attachment of panels 4 to the supporting roof deck which is then followed by the application of the cementitious material or polyurethane foam sealing strips 20 and 23. Since only the seams are covered by the sealing strips, it results in very little additional weight to the roof and requires only a relatively small amount of material in order to provide the thermal and/or physical barrier in contrast to those systems in which the grooves or troughs are completely filled with a particulate material. Next, insulation panels 17 are loose-laid or secured to ridges 7 of panels 4 afterwhich waterproof membrane 18 is laid thereon and secured by fasteners or by ballast 19.
Two full scale compartment fire tests were conducted on prototype roof systems to quantify the effects of the subject roof sealing system. One test had no roof sealing material which is referred to as the "control", and the other test had the openings in the roof deck sealed with gypsum plaster which is one of the cementitious materials discussed above. Each fire test involved placing an "ignition source" below the roof deck and producing a steady flame on the underside of the roof deck. Both roof deck assemblies contained 10 inch thick Expanded Polystyrene (ESP) foam directly applied to the steel deck. The compartment was 12 feet long and 8 feet wide, and there was a full width opening in one of the 8 foot wide walls. The ignition source consisted of a standardized propane-fire burner one foot square which was programmed to produce a steady flame source on the underside to the roof deck. This ignition source represented a serious fire, but a fire that was localized to the rear half of the 12 foot long compartment. There were flames out the front of the compartment within 2 minutes 21 seconds in the control test with out the sealing material. These flames were clearly caused by flammable vapors from the EPS being forced through the two seams in the test deck, and they continued to exit the compartment for over 5 minutes. At times these flames were extending more than 8 feet beyond the front of the compartment. In the fire test with the sealed deck seams there was some light flaming on one of the seams for approximately 3 minutes, but there were only a few flame "packets" that came out of the front of the compartment. There was also some localized flaming at the back of the compartment at intersection of the side and rear wall. This flaming at the back of the compartment was an artifact of a defect in the test set-up where the molten EPS could leak into the compartment.
A video recording was made of the test, and careful observations show that the sealing of the seams prevented the EPS from contributing significantly to the spread of the fire in the test compartment.
Another important measurement in fire testing is the "heat release rate" (HRR). The HRR can be calculated by measuring the oxygen "depletion" in the combustion products leaving the test compartment. The HRR for the control test is shown in FIG. 5, and that for the sealed deck is shown in FIG. 6. The HRR is a good measure of the way in which a material might spread a fire inside a building. The ignition source in these fire tests is between 260 kW and 290 kW, and the most meaningful measure of the fire contribution of a material or system is to subtract the HRR associated with the ignition source and consider the "net" HRR. The net HRR for the control test is approximately 467 kW while that for the sealed deck test is 154, and thus the "control" experiment without the fire stop material gives three times higher HRR than the sealed deck. Thus, a considerable reduction in HRR is achieved by the sealing system of the present invention which materially reduces the amount of molten melted insulation which heretofore dripped into the fire area below the roof.
Thus, the roof system of the present invention provides an extremely simple and inexpensive solution to a problem that has long existed in the art, that is the providing of a thermal and/or physical liquid barrier preventing the molten liquid resulting from the melting of the installation panels from flowing through openings in the roof and dropping into the building space below the roof deck.
Accordingly, the improved metal roof sealing system and method is simplified, provides an effective, safe, inexpensive, and efficient device which achieves all the enumerated objectives, provides for eliminating difficulties encountered with prior devices, and solves problems and obtains new results in the art.
In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used for descriptive purpose and are intended to be broadly construed.
Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described.
Having now described the features, discoveries and principles of the invention, the manner in which the improved metal roof sealing system and method is constructed and used, the characteristics of the construction, and the advantageous, new and useful results obtained, the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims.
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A sealing system and method for a metal roof having a plurality of sheet metal panels attached to a roof deck covered by a layer of insulation, such as polystyrene. The joints and seams formed at junctions of adjacent plates are sealed with a nonflammable or low combustible, char forming, non absorbent layer of material which is applied over the seams in a liquid or slurry form, which subsequently hardens to form a liquid proof seal to reduce the flow of molten polystyrene from melting of the adjacent layer of insulation, into the fire below.
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RELATED APPLICATIONS
This is a continuation of copending parent application Ser. No. 09/764,341, filed Jan. 19, 2001, itself a continuation of international application PCT/SE99/01448, filed Aug. 25, 1999, which designated the United States and was published under PCT Article 21(2) in English.
TECHNICAL FIELD
The present invention relates to a method for character recognition. “Character” is in this compound neutral regarding number, i.e. separate characters, such as letters and numerals, as well as compositions of several characters, such as words, are here referred to. Both generally used characters and imaginary characters are, of course, included.
BACKGROUND ART
There are a plurality of known methods for character recognition, especially for recognition of handwritten characters, which requires especially good interpretation of the character. Several of the known methods are based on the detection of each stroke of the pen when a handwritten character is being formed. Geometric characteristics, such as directions, inclinations and angles of each stroke or part of a stroke, are determined and compared to corresponding data for stored, known characters. The written character is supposed to be the stored character whose geometric characteristics best correspond to the geometric characteristics of the written character. The geometric characteristics are related to an xy-coordinate system, which covers the used writing surface. Such known methods are disclosed in, for instance, U.S. Pat. No. 5,481,625 and U.S. Pat. No. 5,710,916. A problem in such methods is that they are sensitive to rotation. For example, if one writes diagonally over the writing surface, the method has difficult ties in correctly determining what characters are being written.
U.S. Pat. No. 5,537,489 discloses a method for preprocessing the characters by normalizing them. The written character is sampled, and each sample is represented as a pair of coordinates. Instead of solely comparing the characters in the coordinate plane, the transformation is determined which best adjusts the written character to a model character. Indirectly, also rotation and certain types of deformations, which the above-mentioned methods cannot handle, are thus taken into account. The transformation is used to normalize the written character. In particular, the character is normalized by being translated so that its central point is in the origin of coordinates, where also the central point of the model character is found, after which the character is scaled and rotated in such a manner that it corresponds to the model character in the best possible way. A disadvantage of this method is that the normalization requires computing power and that in any case the choice of model characters has to take place by determining what model character the written character resembles the most.
Another method which certainly can handle rotations is disclosed in U.S. Pat. No. 5,768,420. In this known method, curve recognition is described by means of a ratio that is named “ratio of tangents”. A curve, for instance, a portion of a character is mapped by selecting a sequence of pairs of points along the curve, where the tangents in the two points of each pair intersect at a certain angle. The ratio between the distances from the intersection point to the respective points of the pair is calculated and makes up an identification of the curve. This method is in principle not sensitive to translation, scaling and rotation. However, it is limited in many respects. Above all, it does not allow certain curve shapes in which there are not two points whose tangents intersect at the determined angle. It is common that at least portions of a character comprise such indeterminable curve shapes for a selected intersection angle. This reduces the reliability of the method.
SUMMARY OF THE INVENTION
An object of the invention is to provide a method for character recognition, which does not have the above-mentioned disadvantages, and which to a larger extent accepts individual styles of handwritten characters and unusual fonts of typewritten characters, and is easy to implement with limited computing power.
The object is achieved by a character recognition method according to the invention comprising the steps of: detecting a union of characters, preprocessing the union of characters, comparing the preprocessed union of characters with one or more template symbols, and applying a decision rule in order to either reject a template symbol or decide that the template symbol is included in the union of characters, the step of preprocessing the union of characters comprising the steps of: representing the union of characters as one or more curves, and parameterising the curve or curves, characterised in that the step of preprocessing the union of characters further comprises the step of forming, regarding various classes of transformation, one or more shapes for the curve or curves, and that the step of comparing comprises the steps of: forming one or more geometric proximity measures, determining for every shape the values of the geometric proximity measures between the shape and correspondingly determined shapes for the template symbols, and that the step of applying a decision rule comprises the step of: selecting one or more template symbols in consideration of the values.
According to the invention, the term “template symbol” means, as defined in the claim, everything from a portion of a separate character, the portion being, for instance, an arc or a partial stroke and the character being a letter or a numeral, to compound words or other complex characters. In a similar way, the term “union of characters” means everything from a separate character to compositions of several characters. The extension of the mentioned terms will be evident from the following description of embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention and further advantages thereof will be described in more detail below by way of embodiments referring to the accompanying drawings, in which
FIG. 1 shows an example of a union of characters which comprises a handwritten character, and which illustrates some steps in a preferred embodiment of the method according to the invention,
FIGS. 2 a – 2 d and 3 a – 3 d show examples of various transformations of a union of characters which comprises a hand-written character,
FIGS. 4 a – 4 d show an example of recognition of a union of characters which comprises several characters, and
FIG. 5 shows an embodiment of a device for carrying out the method.
DESCRIPTION OF EMBODIMENTS
According to the invention, the method for character recognition comprises a number of main steps:
a) a union of characters is detected,
b) the union of characters is preprocessed,
c) the preprocessed union of characters is compared with one or more template symbols, and
d) a decision rule is applied in order to determine whether or not any one of the template symbols is included in the union of characters.
According to a preferred embodiment, the various main steps are carried out in accordance with the following description. The embodiment is preferably intended for recognizing unions of characters that are written on a pressure-sensitive display, which is available on the market. It should be noted that the invention is just as useful for recognizing typewritten as handwritten unions of characters that originate from a hard copy, which for instance is scanned into a computer. An embodiment which is particularly adapted to recognition of typewritten, scanned unions of characters will be described below. In the following description of the steps of this embodiment, it will for the sake of simplicity be presumed that the union of characters comprises one character.
In step a), points on the character are detected at regular time intervals at the same time as the character is being written on the pressure-sensitive display. Thus, an ordered sequence of points is obtained. In step b), the following operations are carried out. By interpolation between the points, a curve representation of the character is generated. The curve representation comprises one or more curves which pass through the sequence of points. Any lifting of the pen is detected to prevent the interpolation from extending over spaces between points where the pen has been lifted. The interpolation results in characters such as “t”, “ä” and “s” being considered to consist of one or more curves. Each curve or composition of curves is perceived holistically as an indivisible geometric unit. This means, for instance, that the method according to the invention in many ways operates on complete characters (global character interpretation). Each point is represented as two coordinates, which indicate the position of the point in the limited plane that the display constitutes. One of the coordinates which in the following will be called x 1 indicates the position laterally and the second, which will be named x 2 below indicates the position in the vertical direction. The curve is conveniently parameterized as φ(t)=(φ 1 (t), φ 2 (t)), a t b, where, for the sake of simplicity, a=0 and b=1 and are sampled in a number n of points t 1 <t 2 . . . <t n according to any suitable parameterization rule. To begin with, arc length is the rule according to which the parameterization is preferably carried out, which means that the points become equidistantly located. It is to be noted that because of the irregular speed of motion of the writer, this is not the case with the initial coordinate samples. The use of the arc length can be seen as a standardization of the parameterization, which facilitates the following comparison with template symbols, which are parameterized and sampled in a corresponding manner. For some classes of transformation it may be necessary to reparameterize, which will also be described below.
In order to compare the character with template symbols it is necessary to shape a representation which allows quantitative comparisons. Some deviations from a template symbol defined in advance have to be allowed, i.e. for instance an “a” has to be interpreted as an “a”, even if with respect to its shape, it differs to a certain extent from the template symbol. According to the invention, a definition is applied that is based on different transformations. Depending on demands for flexibility and exactness, various classes of transformations may be allowed, the classes comprising one or more types of transformation such as translation, rotation, scaling, shearing and reflection. This is illustrated in FIGS. 2 a – 2 d and 3 a – 3 d . FIG. 2 a shows a handwritten “a”. The other three characters have been subjected to various affine transformations. The class of transformation which is comprised by the affine transformations allows rotation, shearing, reflection, scaling and translation. The characters in FIGS. 2 b and 2 c have been subjected to translation, rotation, scaling and shearing in relation to the character in FIG. 2 a . The character in FIG. 2 d has been subjected to translation, reflection, rotation and scaling.
FIGS. 3 a – 3 d illustrate positive similarity transformations that only comprise scaling, rotation and translation. In accordance with this embodiment of the method according to the invention, permissible deviations are limited to positive similarity transformations. This means that a written character or part of a character, which by a suitable combination of scaling, rotation and translation can be brought into correspondence with a template symbol, is interpreted as the same character or part of the character which is represented by the template symbol. The correspondence does not have to be complete, which will be described below.
The representation, which according to this invention is to be preferred, is provided by forming an invariant of the parameterized curve. Useful invariants should according to the invention allow an interpretation that is close to the interpretation a human being makes of a particular character. This means that characters which a human being with great accuracy of aim is able to interpret correctly, i.e. interpret as the characters which the writer says that he or she has written, should be interpreted correctly and with great accuracy of aim by the method according to the invention. It is thus important that a constructed invariant is selective in a well-balanced way. According to the invention, invariants are therefore constructed on the basis of the following definition. If φ is a parameterized curve according to the above, and G is a group of transformations of curves, then the union is named d(φ)={ψψ=g(φ),g εG} and equivalent rewritings thereof are called the shape of φ. It will be appreciated by those skilled in the art that the definition allows many possible invariants, which, however, all have in common that they handle the curve as the above-mentioned indivisible unit.
According to the preferred embodiment of the invention, the shape corresponding to the group of positive similarity transformations is given by s(φ)=linhull({(φ 1 , φ 2 ), (−φ 2 , φ 1 ), (1, 0), (0, 1)}), i.e. a linear space constructed from the parameterised curve φ. As will be appreciated by those skilled in the art, s(φ) is precisely an equivalent paraphrase of d(φ). In practice, the use of this shape implies, That all parameterized curves, which can be transformed into each other by positive similarity transformations, have the same linear space as shape.
On the contrary, according to another embodiment of the invention, affine transformations are permissible. Then the shape, after rewriting, is given by s(φ)=linhull(φ 1 , φ 2 , 1) which is described in more detail in, for instance, “Extension of affine shape”, Technical report, Dept. of Mathematics, Lund Institute of Technology 1997, by R. Berthilsson.
In step c), the shape of the written character is compared with correspondingly formed shapes for a number of template symbols. In this embodiment of the invention, the template symbols are by way of introduction provided by letting a user write by hand on the display all the characters that he or she might need, one at a time, which are processed in accordance with the above-described steps a) and b) and are stored as template symbols. As mentioned above, each template symbol comprises one or more curves, which represent a portion of a character or the complete character, which in practice means hat several template symbols may be required to build a character. However, as will be further developed below, a template symbol can, on the contrary, also represent a sequence of several characters.
According to the invention, one way to compare the shapes is to use a geometric measure of proximity. For the above formed shapes according to the preferred embodiment and the alternative embodiment, respectively, a geometric proximity measure μ for shapes, which comprise linear sub-spaces within the space of possible parameterized curves S, may be used. An example of such a geometric proximity measure is:
μ=∥( I−P s(φ) P s(ψ) ∥ HS
where HS represents the Hilbert-Schmidt norm and I is the identity.
In the definition, s(φ) and s(ψ) represent such linear sub-spaces. P s(φ) and P s(ψ) further represent orthogonal projections onto s(φ) and s(ψ), respectively. HS represents the Hilbert-Schmidt norm and I is the identity. The calculation of the geometric proximity measure μ includes selecting a scalar product.
A general example of a scalar product of two functions φ(t) and ψ(t) with values in 5 n is:
∑ k = 0 1 ∫ ⅆ k ϕ ( t ) ⅆ t k · ⅆ k ψ ( t ) ⅆ t k ⅆ m k
where dm k are positive Radon measures and · represents the scalar product on 5 n .
Since each sampled curve comprises a plurality of points, each with two coordinates, it is convenient to use matrix notation for comparative processing of the shapes. The steps of describing the curves in matrix notation and constructing a geometric proximity measure can be described and carried out mathematically as follows.
Let us name the curve of the detected character ψ(t)=(ψ 1 (t), ψ 2 (t)), 0 t 1, and the curve of a template symbol φ(t)=(φ 1 (t) φ 2 (t)), 0 t 1. By sampling the curve at the points of time 0=t 1 <t 2 . . . <t n =1, the following matrices may be formed
M
1
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The matrices are QR-factorized in a manner known to those skilled in the art, such that M 1 =Q 1 R 1 and M 2 =Q 2 R 2 , where Q- and Q 2 are orthogonal matrices and R 1 and R 2 are upper triangular. The matrices Q 1 and Q 2 represent the shapes of the detected character and the template symbol, respectively, given the parameterizations and the sampling.
A geometric proximity measure μ may be constructed as follows
μ( Q 1 ,Q 2 )=∥ Q 2 −Q 1 Q 1 T Q 2 ∥ F 2
where the norm ∥·∥ F denotes the Frobenius norm. When 1=0 and dm 0 is the usual Lebesgue measure on the interval [0, 1], in the above general example of a scalar product, exactly this geometric proximity measure is obtained. The choice of scalar product affects the performance of the method.
After the determination of the values of the proximity measure between the shape of the detected character and the shapes of all or a sub-union of the template symbols, step d) is carried out. In this step, each value is compared with an individual acceptance limit which is defined for each template symbol. The template symbols whose values of the proximity measure are smaller than their respective acceptance limits are considered plausible interpretations of the written character. Of these plausible interpretations, the template symbol is selected whose value is the smallest. On the contrary, if no value is smaller than its acceptance limit, a refined determination is made. The acceptance limits may also be one and the same for all of the template symbols. An advantage of using individual acceptance limits is that more complicated characters, such as “@”, tend to have a fairly high value of the proximity measure also in case of correspondence, while simpler characters, such as “1”, generally have a low value of the proximity measure in case of correspondence. Further variants are possible, some of which will be described below.
Theoretically, the proximity measure has to fulfill μ(s(φ), s(ψ)=0 when φ and ψ are parameterizations of the same curve when the curves are obtained from each other with a positive similarity transformation. Since people when writing do not exactly stick to the permissible similarity transformations of the template symbols, the acceptance limits should, however, be selected to be greater than zero.
On the one hand, the acceptance limits are therefore determined to be values which are >0, and on the other hand the case where no value is smaller than its acceptance limit is not interpreted as if the written character does not have an equivalent among the template symbols. Instead, according to this embodiment a reparameterization is carried out, since the parameterization affects the final result to a fairly large extent. A preferred reparameterization of the curve ψ means that it is put together with a one-to-one function γ:[0, 1] [0, 1]. For instance γ:(t)=l−t fulfils this, which means that the character is written in the opposite direction. What sort of reparameterization has to be done is determined by solving the problem of minimization
min γ μ ( s ( ϕ ) , s ( ψ ∘ γ ) )
where the minimization is performed over all of the which have been described above.
The above-described steps are then repeated and new values of the proximity measure are obtained. If none of these is below its acceptance limit, the written character is rejected and the user is informed about this, for instance by requesting him or her to rewrite the character. If one wishes to speed up the determination of the proximity measure after the reparameterization, a group consisting of the smallest, for example the three smallest, values of the proximity measures from the first determination can be selected and in the second determination, only be compared with the template symbols that are included in the group. However, in certain cases this may produce a final result other than in the case where all the template symbols are taken into consideration in the second determination.
The geometric proximity measure y does not only result in a ranking order between different interpretations of a character, but it also gives a measure of how similar two characters are. This yields the possibility of also using the present method for verification and identification, respectively, of signatures (initials are here perceived as signatures). In this use, the arc-length parameterization is, however, not a preferred type of parameterization since it excludes information of the dynamics when writing. Such information is valuable in this use. There are, however, other variants that are more suitable.
The preferred embodiment has hitherto been described on the basis of the fact that there are suitable template symbols with which the written character can be compared. Furthermore, the description has been made for one character. Normally, it is not separate characters, but running text with complete words that are written on the display. From the user's point of view, it is desirable to be able to write running text, which demands much of the method.
A problem in the context is that the union of characters may contain a plurality of character combinations. It is unreasonable to ask the user to write all possible characters or words as template symbols.
At the same time, it is advantageous if a limitation of the shapes of the writing can be avoided. If the user were strictly limited, for instance, only allowed to write one character at a time so that the above-described case always exists, the situation is relatively clear, but not user friendly. According to the invention, the user is allowed to write running text. It is thus difficult to know where in the curve/curves, for instance, a character ends and starts. The points indicating the beginning and the end of a character are named breakpoints, and finding possible breakpoints adds complexity to the problem of recognition. This problem of complexity is solved in accordance with an embodiment of the method according to the invention in the following manner. It should be mentioned that the above steps are carried out in the same way in this embodiment. The following description essentially concerns the step of preprocessing the union of characters and the step of comparing.
If the pen is lifted after each character in a word, this may be taken advantage of. Each lifting of the pen gives rise to a discontinuity and may be detected by two points being relatively far apart in space or time. Naturally, this detection is carried out before the arc length parameterization. The union of characters here consists of n curves. The points of discontinuity may be taken as plausible breakpoints to distinguish two characters from one another. This focuses on the problem of characters containing several strokes that are being written by lifting the pen in between. Such a character will be represented by several curves by means of the detection of discontinuity. However, each curve may be parameterized with rescaled arch-length, which means that each curve contains the same number of sampling points. Assume that l 1 , l 2 , . . . , l n are the curves and that S k is a composition of the curves l to k. Compare the compositions of curves s 1 , s 2 , . . . , s k with the database of template symbols, where k is the largest number of curves included in any template symbol. Assume that s k1 is the longest composition of curves which gives correspondence/correspondences, i.e. which, when comparing with template symbols, gives one or more values of proximity measures that are below the acceptance limit/acceptance limits. Even if s k1 corresponds to one or more template symbols, it is not certain that this gives a correct interpretation. In accordance with this embodiment of the method, a plausibility test is therefore carried out, which will be described below. If the interpretation is not plausible, s k1 is shortened to the longest composition of curves s k2 but one, which gives correspondence. The plausibility test is carried out once more.
If no interpretation is plausible for any s k , the best interpretation of s 1 is selected. The remaining curves are processed correspondingly. Only the points of discontinuity are not sufficient as plausible breakpoints as far as coherent writing is concerned, but there may also be breakpoints within a curve. It is to be noted that as a matter of fact the above procedure to find breakpoints is achieved with reparameterizations of the composition of all written curves.
The term “plausibility tests” covers, inter alia, so-called confidence sets. The above reasoning of the recognition of unions of characters consisting of several characters, and characters consisting of several curves, respectively, will now be exemplified by means of FIG. 4 a – 4 d , the confidence sets being used as plausibility tests.
Assume that the written character is “ata” (English “eat”), i.e. a complete word written in accordance with FIG. 4 a . By means of detection of discontinuities and reparameterization with rescaled arch length, “ã” has been identified and “t” is the next in turn. The horizontal as well as the vertical stroke can be interpreted as an “l”, i.e. “t” can be interpreted as “ll”. The template symbols are stored with associated confidence sets according to FIG. 4 b , where the template symbols “l” and “t” are shown with the respective confidence sets as the shaded area. Assume that the vertical stroke of “t” is interpreted as the template symbol “l”. The transformation a:5 2 5 2 may then be determined—within the class that generates the shape—which transfers the template symbol in the vertical stroke. If α is applied to the confidence set, the result of FIG. 4 c is achieved. The next curve, i.e. the horizontal stroke, is in the confidence set, which is forbidden, and the interpretation is classified as implausible. The confidence sets do not need to be identified by only straight strokes, as those skilled in the art will realize, but may have a more general appearance. To each template symbol another confidence set can be connected which contains the first set. If then the next curve is also outside the second confidence set, it will be interpreted as if the next character is the first one in a new word.
An alternative plausibility test means that the transformation which was determined in the description of confidence sets is studied. If the transformation is beyond a certain scope, the interpretation will be classified as implausible. Such scope may, for instance, determine how much the transformation is allowed to turn the character in relation to how much earlier interpreted characters have been turned. Also excessive deformations may be excluded. In order to distinguish, for example, “S” from “s”, the enlargement of the transformation can be calculated in relation to the enlargement of symbols that have been interpreted before.
The above-described embodiments of the method according to the invention should only be seen as non-limiting examples, and many modifications apart from the above-mentioned ones are possible within the scope of the invention as defined in the appended claims. Examples of further such modifications follow below.
As an alternative to the above-described reparameterization, the decision is taken directly on the basis of the first determined smallest value of proximity measure.
Examples of other modifications are the choice of another proximity measure, various choices of values of acceptance limits that demand a certain adaptation to various users, different types of reparameterization and different types of shape, for instance, an affine shape.
As far as various types of shape are concerned, two or more shapes are, as an alternative, used in parallel for each union of characters. This means that several invariants are provided for each union of characters and are then processed in parallel in the following steps. This gives a higher degree of accuracy and a faster recognition.
In practice, the method according to the invention can be used, for instance, in electronic notebooks and the like and in mobile telephones with an enhanced possibility of communication by a writable window.
The method according to the invention can be implemented as a computer program in a computer by using a commercially available programming language for mathematical calculations, such as C, C++ or FORTRAN, or as a specially detected unions of characters are stored. By means of the processing unit, calculation operations are carried out, which comprise the interpretation of the sequences of points as one or more curves, the parameterization of each curve, the comparison of the preprocessed union of characters with template symbols and the application of the decision rule. In the memory unit 50 , also software for carrying out the method is stored. The control unit 48 runs the program and communicates with the user via the display communication unit 44 and the display 42 .
The device is also adapted for optional settings which, inter alia, may comprise the choice of shapes, the choice of proximity measure, the choice of parameterizations and the choice of decision rule. The choices are made via the display 42 .
Above, the description has essentially been made on the basis of the characters being written on a display and being detected at the same time as they are written. An alternative is that the characters are detected, for instance scanned, as they are already written on a piece of paper. This concerns handwritten characters as well as typewritten ones. Thus, the detection comprises, instead of the operation of recognizing the display writing, the operation of reading (scanning) the characters on the piece of paper. Advantageously, read data is transformed into said ordered sequence of points by edge detection. However, it is also a modification within the scope of the invention. In this embodiment, the preprocessing comprises forming one or more characteristic curves, for instance the edge curve or edge curves of the character, on the basis of said edge detection and parameterization. When the edge curves thus have been defined, the following steps are the same as in the above-described, preferred embodiment.
The decision rule may be selected in many different ways. A variant of the above-mentioned is that all the template symbols for which the value of the proximity measure below the acceptance limit is selected. Subsequently, the template symbols may be processed further in accordance with any refined determination of the above-described type. It is also possible to make a combination with another selection method, which points out the most plausible alternative. One example of such a method is statistics of characters that indicate the probability of the presence of separate characters or compositions of characters in texts.
Moreover, an alternative for determining the acceptance limits is that the template symbols are grouped, in which case the same limit applies within a group.
The method according to the invention is reliable in that it is able to recognize rather deformed characters and manages running text. The contents of the database are not crucial, but in principle a set of separate characters is sufficient. In order to recognize a variety of fonts and handwritings with a high degree of accuracy, it may, however, be an advantage to store several variants of each character, which comprise deformations that are outside the class of transformation which is appropriate and permissible in the comparison. It may also be advantageous to store certain compositions of characters, for instance to be able to more safely distinguish two “l” “ll”, which are connected, from “μ”.
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Character recognition includes detecting a union of characters, preprocessing the union of characters, comparing the preprocessed union of characters with one or more template symbols, and applying a decision rule to either reject a template symbol or decide that the template symbol is included in the union of characters. Such preprocessing involves representing the union of characters as one or more curves, and parameterizing the curve(s); and, regarding various classes of transformation, forming one or more shapes for the curve(s). The comparing operation involves forming one or more geometric proximity measures, and determining for every shape the values of those measures between the shape and correspondingly determined shapes for the template symbols. Applying a decision rule involves selecting one or more template symbols in consideration of the values.
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FIELD OF THE INVENTION
The present invention relates to unmanned aerial vehicles (UAVs). In particular to a modular design aircraft for the efficient high speed transportation of cargo and freight, and the completion of missions where unacceptably high risks make the use of human piloted vehicles unfeasible.
BACKGROUND OF THE INVENTION
There has been a recent increased emphasis on the use of unmanned aerial vehicles for performing, various activities in both civilian and military situations where the use of manned flight vehicles is not appropriate or efficient. One particular potential application is air cargo and freight transportation.
The process of shipping goods throughout the world is complicated by various factors such as geographic remoteness, lack of ground transportation infrastructure, political instability and environmental factors such as temperature. In some cases while it is possible to ship goods to remote or hard to reach locations, the risk to human life is too great to utilize conventional air cargo.
Transportation of cargo within remote undeveloped areas, for example, sections of Africa, Asia and South America is presently difficult because of the geographic remoteness and lack of ground transportation infrastructure. Therefore, goods shipped by land face a long and arduous journey, while conventional air cargo can be prohibitively expensive.
Another problem with the shipment of cargo arises from the lack of infrastructure to handle the volume of freight to be moved in a time efficient manner. For example, most trade in Europe in accomplished by utilizing ground freight containers. There are currently a large number of container ports being utilized, however due to the ever-increasing volume; the movement in and out of these container ports is severely restricted. In addition, because of the formalities required at border crossings, traffic flow is constrained, thus increasing transportation time and cost.
A further problem encountered using convention air freight methods has been reaching locations that have severe weather conditions such as in the Artic and Antarctic. These locations are typically accessed using air transport during temperate seasons due to the risks to pilots and other aircraft personnel presented during seasons severe weather. Such seasonal supply limitations presented by weather conditions can present difficulties for personnel stationed in these regions, especially in emergency situations such as medical emergencies.
A further problem associated with conventional air vehicles is the risk encountered by pilots engaging activities such as fire fighting. Conditions such as pilot fatigue, darkness, and environmental factors caused by the fire all present increased risk factors to pilot performing this type of activity.
In addition to the factors concerning the difficulties in moving freight and cargo due to geographic and environmental factors, the use of conventional air freight also presents several logistical problems. Such logistical problem prevalent in conventional air freight operations are the time needed to load and unload a plane, and the expense of the aircraft. Loading and unloading aircraft in the conventional manner generally requires the movement of the cargo in small discreet loads, such as palletized loads. The use of palletized loads is an inefficient use of an air transport vehicle because time spent on the ground increases turn-around time, (the time required to unload an aircraft, perform service, and load the next freight shipment), which slows the process for moving freight.
Additionally, the high cost of an air cargo vehicle, especially with respect to the size of the load that can be transported, is a problem. For example, the cost of ground transportation per unit of mass transported is far less than the cost of air transportation per unit of mass transported. A portion of the excess cost is due to the greater cost of the air transport vehicle in relation to the ground transport vehicle and the cost of operation, another factor is the high cost of air crews (pilots, copilots which materially add to the operational cost of the vehicle. A factor in increasing both of these costs is increased cost of aircraft avionics in relation to ground based vehicle control systems and aircraft cabin environmental controls.
Prior air cargo systems did not satisfactorily address these problems. The prior air cargo vehicles were not designed to satisfy these particular uses. The present air cargo vehicles tended to be inefficient to load and unload due to the difficulty access to the cargo hold and the manner in which cargo had to be loaded into the vehicle. Environmental factors also limited the usefulness of prior art systems. The prior air cargo vehicles were relatively expensive as well.
None of the prior air cargo vehicles satisfactorily provided the efficiency of transporting cargo and freight that is desired. It is therefore desirable to provide such a vehicle that will allow cargo and freight, to be easily and securely transported to remote areas, lacking in infrastructure to adequately provide for ground transportation needs using a low cost and efficient vehicle. In addition, there is a need for an air cargo and transport system to provide airborne service in applications of high risk in order to accomplish essential tasks.
SUMMARY OF THE INVENTION
The present invention accomplishes those needs by providing a unmanned aerial vehicle (UAV) of modular design for efficiently and inexpensively transporting cargo and freight to remote or hard to reach area and to perform tasks that would otherwise be too risky for a manned aircraft to undertake. The UAV of the present invention provides a modular design aircraft that can be remotely piloted or autonomously controlled by way of an on-board computer system. The design of the present invention provides a modular gondola and an air vehicle. The modular gondola includes an interchangeable electronics bay, avionics, telemetry, Forward Looking Infrared Radiometer (FLIR), Side-looking Aperture Radar (SAR) and other systems required to remotely locate and pilot the aircraft. The air vehicle includes the structural and aerodynamic and aircraft elements as well as engines. The structural elements of the aircraft include the fuselage cargo bay and support structures for aerodynamic elements and engines. The aerodynamic elements include the wings and all control surface required to generate sufficient lift and control flight. The modular gondola and air vehicle utilizes quick release connectors to attach all control systems to the air vehicle. The gondola and aircraft structure can be attached and separated in the same manner as a typically road going tractor truck and trailer unit. The present invention further provides the capability to remotely control the aircraft without the need for an onboard pilot. Therefore the gondola portion of the aircraft need not include any facilities for accommodating a human pilot such as seating, environmental controls, or safety features to protect the pilots. Additionally, the aircraft of the present invention can be flown in conditions what would in prior systems pose an unacceptable risk to the human pilots onboard. Furthermore, the present invention incorporates an air vehicle for receiving a freight container, such as, for example a container typically used in the ground transportation industry. The air vehicle will be adapted to be of sufficient size for such a container to be easily loaded and unloaded. The loading and unloading can thus be accomplished quickly and with a minimum of manual labor.
The present invention therefore provides a modular automated air transport system comprising an unmanned autonomous aircraft having a selectively detachable control systems portion and a structural air frame portion, wherein the structural air frame portion contains an interior cargo hold, aerodynamic members having control surfaces and at least one propulsion device attached to the structural air frame portion; and wherein the control system portion includes a control computer for autonomously controlling the flight of said air transport system from one known location to a second known location.
These and other features of the present invention are evident from the drawings along with the detailed description of preferred embodiments.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram of the UAV system of the present invention.
FIG. 2 is a side view of the UAV of the present invention.
FIG. 3 is a side view of the air vehicle and gondola of the present invention.
DETAILED DESCRIPTION
Referring in more detail to the drawings, as shown in FIGS. 1-3 , a preferred embodiment of the present invention is described. It is to be expressly understood that this exemplary embodiment is provided for descriptive purposes only and is not meant to unduly limit the scope of the present inventive concept. Other embodiments and variations of the carriers of the present invention are considered within the present inventive concept as set forth of the claims herein. For explanatory purposes only, the unmanned aerial vehicle of the preferred embodiments is discussed primarily for use as a cargo and freight transportation system. It is to be expressly understood that other types of equipment are contemplated for use with the present invention as well.
The unmanned aerial vehicle (UAV) system, as shown in FIG. 1 , is a preferred embodiment of the present invention. UAV system 100 includes a ground station 102 and an UAV 104 , wherein the UAV includes a modular gondola 106 and air vehicle 108 . The ground station systems include flying 110 and maintenance 112 systems. The flying systems include data for navigation, flight control, communications, autopilot, engine control, flight planning, and vehicle monitoring. The maintenance systems include operations and facilities for aircraft loading and unloading as well as repair of the air vehicle and gondola of the present invention.
Turning now to FIG. 2 , there is shown a depiction of the UAV of the present invention. The UAV includes a gondola 202 and air vehicle 204 . The gondola 202 portion houses a central control computer embodying the avionic componentry, for performing the functions of navigation, flight control, communications, autopilot, engine control, flight planning, TCAS and ATC communications radio and vehicle monitoring. All avionic would include redundancy in order to eliminate catastrophic single and dual point failures. The gondola 202 would be attached to the air vehicle 204 by way of quick disconnect “umbilical” wiring which will connect all avionics to the air vehicle. In this way, the gondola portion can be used interchangeably between various air vehicles. It should be apparent to one skilled in the art that the central computer of the present invention would be open architecture and programmable.
In the preferred embodiment, navigation will be implemented using Global Positioning System (GPS). GPS is available worldwide on a full time basis, in addition it provides sufficient accuracy to handle take-offs, in flight navigation, approach and landings. In addition, enhancement such as radar and altimeter can be added to the GPS system to control dynamic in-flight conditions such as air space separation and landing.
Actual flight control can be handled by an autopilot system as is known in the art. For example, the autopilot system may include be the S-TEC® system sold by Meggitt Avionics/S-TEC, Mineral Wells, Tex. Such autopilot systems are easily integrated into GPS and vehicle controls.
Engine control is accomplished through the use of Full Authority Digital Engine Control (FADEC) Interface that is well known in the art. This interface provides complete integration of engine controls with the flight control central computer and other related avionics systems. The modular design of the UAV of the present invention facilitates the reduction of turn around time by providing the capability of attaching a gondola 202 to a waiting and loaded air vehicle 204 . Therefore, the UAV of the present invention can be utilized in much the same way as ground based tractor-trailer or railroad transportation, wherein trailers or cargo cars are loaded independently of the power source, thereby increasing the efficient use of the cargo carrying and power component. Additionally, costs for operating the UAV of the present invention can be minimized by the modular design since a single gondola can be attached to a plurality of air vehicles. Alternately, the present invention can be implemented using a single structure air vehicle. In such an embodiment, the central computer can be an open architecture and programmable design, quick turn-around of the air vehicle can be accomplished by reprogramming the central computer after a flight leg, while the cargo is being unloaded and loaded. The single structure UAV is utilized in the same way as the modular design embodiment without the need for removing or attaching the gondola component. In this embodiment cargo can be maintained in a plurality of containers which are “staged” awaiting loading onto a predetermined UAV.
Turning again to FIG. 2 , there is depicted a preferred embodiment of the air vehicle of the present invention. The air vehicle 204 includes the fuselage 206 , the aerodynamic surfaces (not shown), control systems (not shown), the engines 208 and landing gear 210 . The fuselage can be formed of a variety of structural designs to satisfy the parameters of the present invention, such as a monocoque design or other designs known in the art. In a particular embodiment, the fuselage structure can be partially provided by the cargo container. As will be hereinafter described, the air vehicle is adapted to receive a standard cargo container, which once loaded onboard is rigidly affixed to the air vehicle fuselage. In that way it becomes a stressed member of the fuselage structure, contributing to the torsional stiffness of the structure. Therefore, the fuselage is less expensive to construct since some of the structure is provided by the cargo vessel. In a preferred embodiment the air vehicle of the present invention should have the capability to carry a loaded standard shipping container weighing up to 30000 lbs. It is also desirable to have the ability to load and unload the such a container in a short period of time, directly from the cargo hold of the aircraft as a single load to a wheeled vehicle without separating the load into a plurality of packages. The loading and unloading of a single cargo vessel will facilitate the quick turnaround of the UAV. The turnaround time would include loading, unloading, fueling, flight planning. The UAV is designed to operate autonomously as a remotely piloted vehicle having no flight crew.
To meet the operational requirement of the UAV of the present invention, having a payload mass fraction of about 33%, the vehicle will have a gross weight on the order of approximately 90,000 pounds, having sufficient power to fly at modest speeds of 150 to 180 knots. Projected cruising altitude is expected to be approximately 10,000 to 15,000 feet. The UAV design approach is to make a mechanically simple vehicle to reduce the manufacturing costs. For example, the wing would be a constant cord design to minimize tooling and wing complexity. Additionally, advanced assembly techniques would be used such as friction stir welding in order to decrease costs of fabrication and assembly.
The wings of the air vehicle of the present invention would be of high lift design, which, while resulting in slower flight speeds would eliminate the need for complex high lift devices such as flap and slats. These devices materially complicate the design, cost, and maintenance of the aircraft. A similar approach to design will be applied to all aspects of the air vehicle, in order to minimize costs and complexity.
The air vehicle flight control system will include a conventional six degree of freedom (three axis) control mechanism. The aircraft will use ailerons for roll, elevator for pitch, and rudder for yaw with the control surfaces actuated either hydraulically or electronically. Additionally systems such as landing gear will be designed to accommodate use on airfields in undeveloped areas where uneven or unpaved landing sites are likely to be encountered. For example, the tires used will be a wide, low-pressure design to permit the air vehicle to land on unpaved landing areas, such as a grass field.
In the preferred embodiment, the aircraft of the present invention will be powered by propeller driven turbine engines, in order to meet the flight profile for altitude and range. For example, the engines may include turbine propeller engines sold under the trade designation AE2100® by Rolls Royce/Allison Corporation, Indianapolis, Ind.
Turning now to FIG. 3 there is shown the UAV 302 of the present invention. In the embodiment depicted, the air vehicle is adapted to carry cargo by receiving standard cargo containers 304 which are known in the art, into the cargo hold, 306 . Typically, such containers are carried on wheeled trailers 308 as shown. The preferred embodiment of the UAV of the present invention will receive the container through a hinged ramped door 310 in the rear of the aircraft. In that way the cargo can be loaded or unloaded in a single action without long delays or extensive use of manual labor. The air vehicle of the present invention will also incorporate weight sensing devices throughout the cargo bay. Thus, when a cargo container is loaded into the air vehicle, the total weight, as well as the weight distribution of the load can be immediately measured. The central computer of the UAV according to the present invention can be programmed to calculate any changes to total weight and weight distribution as needed.
The use of a rear hinged door to access the cargo hold will also facilitate the removal of cargo by use of a parachute drop, wherein the container is slid out the rear of the plane during a low speed, low altitude pass over an appropriate drop site, where actual landing of the plane is not feasible. The ramped door can have several operating positions. For example, the ramp would be lowered to the ground so that containers on the ground could be slid up the ramp for loading. The door can also have an intermediate position to load containers directly into the body of the air vehicle from a truck. The air vehicle can also be equipped with a winch to assist in loading and unloading of containers. It should be understood that the ramp can be raised or lowered to accommodate the loading of a container from a variety of positions.
In an alternate embodiment, the UAV of the present invention can be adapted to utilize a hinged front opening, however the front loading method would obviously preclude the delivery of cargo by parachute drop it would have the advantage of requiring less structural reinforcement of the air vehicle.
In addition to the UAV, the system of the present invention includes a ground station for flight and maintenance control. The flight control portion includes data for navigation, flight control, communications, autopilot, engine control, flight planning, and vehicle monitoring that is downloaded to the central control computer of the gondola 202 .
In a preferred embodiment, the UAV system of the present invention will include a central hub ground station and a plurality of remote locations. The central hub location will encompass the functions of control the fleet of UAV's including fleet scheduling, service and scheduled maintenance and flight planning. Flight planning will include the generation of flight plans as well as their transmission to remote locations for installation into UAV's awaiting flight plans for ensuing routes.
In a remote location, a ground crew will provide the functions of loading/unloading, fueling for the ensuing leg of the flight, flight plan downloading and installation into the gondola central computer and resolution of any exigent maintenance issues.
In operation, the UAV of the present invention in a preferred embodiment will receive a cargo load from a wheeled vehicle. The cargo load will be contained in a standard 40 foot shipping container as used in the freight industry. The container will be loaded onto the air vehicle preferably through a rear door ramp system and secured therein. Prior to, or during loading the air vehicle would be services as needed. Service may typically include fueling, structural inspection, inspection of aerodynamic and control devices and engine servicing.
A trained ground crew would conduct all of the loading and servicing procedures in order to prepare the air vehicle for connection to the gondola and subsequent flight. If the air vehicle is not already connected with a gondola, it can be held in a staging area until a gondola is available. Once available, the gondola will be attached to the air vehicle. The gondola electronic flight systems will be programmed with all flight plan information. Flight planning would be accomplished from a central headquarters, transmitted to the remote location, preferably by way of a wide area network, such as the internet or by satellite link. The flight plan data would then be transferred to the central computer of the gondola. Once the flight plan has been transferred to the central computer the program would be instantiated and the UAV launched to autonomously complete the flight plan. While in flight the central computer would provide continuously monitoring of all vehicle functions. Furthermore, the flight computer can provide telemetry to transmit data concerning all monitored systems to a ground based central station.
The complete flight plan would also include approach and landing data, although in an alternate embodiment, approach and landing could be controlled by a ground based system at the arrival location. This system could be under the control of a “operator” utilizing a two way telemetry system or a computer based expert system for controlling approach and landing at a particular location. Once completing the flight plan, the UAV of the present invention is met by ground crew that unloads the air vehicle, transfers the container to wheeled ground transport, performs maintenance and prepares the UAV for subsequent flights. The ground crew can also transfer the gondola to a waiting air vehicle, download a new flight plan and program the gondola central computer for the next flight. Alternately, the central computer of the present invention can be remotely programmed without the intervention of the remote location ground crew. Such programming could occur by utilizing a direct RF link from the central headquarters utilizing satellite technology for example.
Various changes to the foregoing described and shown structures will now be evident to those skilled in the art. Accordingly, the particularly disclosed scope of the invention is set forth in the following claims.
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A modular automated air transport system comprising an unmanned autonomous aircraft having a selectively detachable control systems portion and a structural air frame portion, wherein the structural air frame portion contains an interior cargo hold, aerodynamic members having control surfaces and at least one propulsion device attached to the structural air frame portion; and wherein the control system portion includes a control computer for autonomously controlling the flight of said air transport system from one known location to a second known location.
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BACKGROUND OF THE INVENTION
This invention relates to melting and refining glass for the manufacture of glass articles, particularly for the manufacture of flat glass. More particularly, this invention relates to the application of heat to glass batch materials in a glassmaking furnace adapted for heating such materials as they float on and advance along the surface of a pool of molten glass maintained in the furnace.
Glass batch materials have been melted and molten glass refined and conditioned by the application of heat to glass batch and to molten glass from a variety of sources in furnaces of varied design. Today, for the commercial production of glass products on an efficient scale, molten glass is prepared for forming in furnaces of several general kinds. These are fossil-fueled furnaces, such as regenerative furnaces and recuperative furnaces, electric furnaces of the kind illustrated in U.S. Pat. No. 2,225,616 and U.S. Pat. No. 2,225,617. There are fossil fuel-fired furnaces which include electric-boosting electrodes as shown in U.S. Pat. Nos. 2,397,852, 2,600,490, 2,636,914 and 2,780,891. These patents and many other patents and publications illustrate that for many years there has been widespread interest and activity in the use of electricity to melt glass batch and to heat molten glass.
According to the prior art, heating electrodes have been employed in glassmaking furnaces in several different ways. For example, electrodes have been used in batch charging kilns, as in U.S. Pat. No. 2,397,852, and along the walls of furnaces, as in U.S. Pat. No. 2,975,224, to heat naturally cold regions of the furnaces where heat is normally lost to the outside environment. When used near side walls of a horizontal furnace, electrodes have served to establish convective flows in molten glass which keep unmelted batch in the center of the furnace away from its side walls.
In general, when both electricity and fossil fuels have been used to provide heat to the same glassmaking furnace, the fossil fuels have been employed to melt glass batch in the region of the furnace where batch is advancing freely through the furnace from its charging kilns. Electrodes have been positioned in the furnace well downstream from where batch is charged in order to heat molten glass beyond the region of unmelted batch and to strengthen the convective flow, known as the "spring zone" flow, within the molten glass as shown in U.S. Pat. Nos. 2,512,761, 2,636,914 and Canadian Pat. No. 634,629.
Given a comprehensive view of the prior art relating to the use of electric heating electrodes in glassmaking furnaces, it is apparent that it is well known that such devices may be used to advantage. The questions facing an artisan in the glassmaking art are not concerned with whether or not to consider the use of heating electrodes. Rather, the questions are: Where should heating electrodes be placed in a furnace? How should those electrodes be used in combination with the other elements of the furnace to achieve a desired benefit?
The specific problems confronting the present applicants have not been considered in the past as being directly relevant to electric melting and heating glass. In a horizontal glassmaking furnace, whether regenerative or recuperative, there are undesired fuel inefficiencies and there is a problem of unmelted batch being blown from the furnace through checker brick packing to the stack or exhaust system serving the furnace. The first of these problems would invite at least a study of the potential of electric heating, but the applicants have discovered that both problems can be greatly alleviated by a particular application of electric heating to a glassmaking furnace.
SUMMARY OF THE INVENTION
As glass batch materials float on and are advanced along the surface of a pool of molten glass in a horizontal glassmaking furnace, heat is applied to the molten glass beneath the advancing glass batch and the otherwise usual flow of gases (flames) over the advancing unmelted glass batch is kept so insubstantial as to avoid batch pickup and discharge to the environment. The heat, which is applied from below the advancing unmelted batch, results from the application of electric power to submerged electrodes.
Meanwhile, beyond the unmelted glass batch, where the upper surface of the pool of molten glass is exposed, heat is applied from above to the molten glass to provide sufficient heat to assure a spring zone flow remote from the electrodes and thus insure sufficient residence time upsteam of the spring zone to thoroughly homogenize the molten glass. This overhead heat may be provided by electric resistance heaters but is preferably provided by flames from the combustion of gas, oil, powdered coal or other fossil fuels.
The heat, which is supplied to the molten glass beneath the advancing unmelted glass batch, is preferably provided by the action of electrodes extending into the furnace beneath the surface of the pool of molten glass. When a suitable voltage is imposed between electrodes which are spaced from one another, current passes through the molten glass between them and the glass is heated according to the well-known Joule heating effect. The electrodes are spaced a sufficient distance from where the glass batch is charged to the furnace so that it is freely advancing along the surface of the molten glass above the electrodes.
A plurality of undesired small spring zone flows, such as encountered generally with electric melting schemes, are avoided. Also, to the extent that heat is added from below the floating unmelted batch materials, heat input from above may be avoided. As a result, there is established one vigorous spring zone flow which is located a substantial distance downstream from the batch line where melting is completed. It is the overhead heating downstream of the batch line that provides for a continued rise in surface glass temperature beyond the batch line which permits the downstream displacement of the spring zone and the early refining of the molten glass.
This method is particularly applicable to the melting and refining of glass in a horizontal, regenerative-fired, glassmaking furnace. In such a furnace, particularly a typical one having from five to eight side firing ports on each of its elongated sides, a row of electrodes is positioned across the bottom of the furnace between the first and second firing ports downstream from the charging end of the furnace. The first two or three firing ports on each side of the furnace are dampered or completely closed off to slow or stop the flow of gases from the furnace over the unmelted batch and out through those ports to the regenerators.
Optionally, a drop arch or like barrier is extended across the headspace of the furnace above the molten glass and unmelted batch downstream of the last dampered or closed ports to segregate the headspace into two regions: one above unmelted batch and one above the exposed upper surface of the pool of molten glass. Of course, the exact location of the batch line where the batch finally is all melted may vary slightly upstream or slightly downstream from the location of such a barrier without detrimental effect. By placing this barrier in the furnace, the flow of gases over unmelted batch is further reduced so that discharge of fine particulates from the furnace with the exhausted products of combustion is reduced with a consequential benefit to the environment. The barrier may be positioned between the third and fourth ports of a furnace or between its fourth and fifth ports or even between its fifth and sixth ports as the furnace size, regenerator design, glass composition and fuel employed may dictate.
This invention is particularly applicable to the manufacture of flat glass wherein large amounts of molten glass are continuously prepared and formed into a continuous sheet or ribbon of flat glass. Flat glass, of course, is a term of art embracing flat, as well as curved or bent, glass made in sheet or plate form by any known forming process including sheet drawing processes, glass floating processes, rolling processes and the like. Typical glass compositions which may be efficiently produced according to this invention include soda-lime-silica glasses, borosilicate glasses, alumino silicate glasses, borate glasses and the like.
In a typical embodiment of this invention a glass is made from a glass batch comprising from 5 to 50 percent by weight cullet (recycled glass) and the remainder from 95 to 50 percent by weight raw batch materials including sand, soda ash, or caustic soda, limestone, dolomite, rouge or other colorants, coal and salt cake. When this invention is practiced, the unmelted batch floating on the pool of hot molten glass prevents the ready escape of sulfurous compounds from the melt during melting and reaction. Sulfur emissions from the furnace are reduced and, ancillary to that, the amount of flux, such as salt cake, in the batch can and must be reduced to maintain a desired blanket of unmelted batch over the molten glass. Therefore, not only are emissions reduced but also waste of flux materials is reduced as well.
Details of this invention may be further appreciated with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic sectional longitudinal elevation view of a glassmaking furnace having the features of this invention.
FIG. 2 is a partial plan view of the furnace of FIG. 1 taken along line 2--2 of FIG. 1; and
FIG. 3 is a partial plan view of a furnace showing the same portion as shown in FIG. 2 and illustrating a preferred electrode arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown a regenerative glassmaking furnace having a melter 31 connected to a refiner 33 to which there is connected a molten glass delivery facility 34.
The furnace includes a melter bottom 35, a back basin wall 37 and melter side walls 39. The side walls 39 include conventional lower basin wall and upper breast wall portions (unnumbered). The furnace further includes an upper or suspended back wall 41 and a roof or crown 43. As described above, the furnace may be provided with a drop arch or barrier 44 extending transversely across the upper or headspace portion of the furnace at about the location where glass batch melting is to be completed. This barrier 44 may be located as shown or may be as far downstream as between the fifth and sixth ports (the burner of the fifth port is indicated by numeral 47 while the sixth port is indicated by numeral 47).
The furnace is an elongated one as seen in FIG. 1 and it has a plurality of firing ports 45 through its elongated side walls 39. These ports 45 are connected to regenerators (not shown) on either side of the furnace. Extending into each firing port 45 which is to be fired is a burner 47 through which gas, oil or other fuel may be directed for combustion at the tip of the burner 47. Preheated air enters the furnace headspace through the ports 45 around the burners 47. The air is preheated by passing through the regenerator on one side of the furnace in the conventional way as only the burners on that side are fired at a given time. The products of combustion are exhausted from the furnace through its ports and regenerator on the opposite side from that where firing is accomplished. Firing is periodically reversed from side to side in the usual way.
The furnace is generally provided with skim kilns 49 near the downstream end of the melter 31. The terms "upstream" and "downstream" refer to the general direction of glass flow through the furnace so that in FIG. 1 the left side is the upstream end and the right side is the downstream end of the furnace.
The firing ports 45 in the upstream end of the melter 31 are provided with dampers 50 to isolate the headspace at that end of the furnace from the regenerators.
The refiner 33 includes a refiner bottom 51, a front basin wall 53, an upper front wall 55, a roof or crown 57 and side walls 59. The melter 31 and refiner 33 are joined through a bridge wall 61 and waist or tapered wall sections 63. The refiner 33 may be provided with skim kilns 65. Joining the melter bottom 35 and refiner bottom 51 is a bottom section including steps 67 and planes 69. The heights of the steps and lengths of the planes are designed to aid in the establishment of desirable flows in a pool of glass 70 which resides in the lower portion of the furnace.
Coolers 71, 73 and 75 may be disposed across the furnace and submerged in the glass in the manner shown in U.S. Pat. No. 3,836,349 in order to regulate the flow of molten glass within the furnace.
The major molten glass flow streamlines are illustrated in FIG. 1. A "spring zone" 71 is established in the melter 31 at about the location of maximum glass temperature in the vicinity of the last fired port. The "spring zone" is a region of upward convective flow in the pool of molten glass. Downstream of the spring zone the convection flow of glass has a return flow stream along the bottom of the furnace as illustrated by streamlines 79, 81 and 83, while upstream of the spring zone there is a return flow 85. Moving away from the spring zone in a downstream direction is the major flow stream 87 including the throughput component of flow 89 which continues out of the furnace as it is delivered for forming. As will be seen below, these flows are important to the present process for they serve to distribute the heat introduced into the furnace to all the glass in the furnace.
Glass batch materials 90 are charged into the furnace over its back basin wall 37. After the batch materials 90 are pushed beneath the suspended back wall 41, they advance freely along the surface of the molten glass 70. Electrodes may be mounted in the furnace in several ways. Any or all of the illustrated groups of electrodes may be provided.
A pair of end-mounted electrodes 101 and 101' may extend into the furnace through the back wall 37. The electrodes are provided with connectors 103 and 103', respectively, which are connected to a source of electric power (not shown).
Bottom electrodes 105 and 105' may be provided in the central portion of the furnace. These are extended through the melter bottom 35 and provided with connectors 107 connected to a source of electric power (not shown). If desired, additional bottom electrodes 109 and 109' may be provided with these electrodes having connectors 111.
Side electrodes 113 and 113' may also be employed. These extend through the side walls 39 and are provided with connectors 115 and 115' which are connected to a source of electric power (not shown).
Alternating current is used in order to provide sufficient power density to heat the glass generally without developing sustained excessive resistance heating at the ends of the electrodes or at the remaining electrode-glass interfacial regions. Electrodes may be paired and connected to a single-phase source of power or grouped in groups of three and connected to a three-phase source of power.
In a particularly preferred embodiment of this invention, a row of bottom electrodes extends across the furnace between the suspended or upper back wall 41 and the third firing ports of the furnace. As shown in FIG. 3, this row of electrodes 105a through 105e and 105'a through 105'e extends across the furnace between the first and second ports. Groups of three electrodes are connected to a source of three-phase electric power with electrodes 105c, 105d and 105e being grouped together, for example.
In order to monitor the application of heat to the furnace, it is desirable to mount thermocouples 117 and 117' and thermocouples 119 and 119' in the bottom of the furnace.
When carrying out the present process in a furnace having an electrode arrangement as shown in FIG. 3, overall energy requirements should be reduced on the order of 15 to 20 percent compared to the energy required to melt and refine glass in the same size furnace using overhead firing alone. On a typical horizontal regenerative furnace having six ports on each side and melting glass at a rate of from 400 to 600 tons per day (4.1 × 10 3 to 6.1 × 10 3 kilograms per day) by burning natural gas or oil at all ports, it is possible to energize a row of electrodes beneath the glass between the first and second ports, terminate firing through the first two ports and decrease firing through the third port and maintain the rate and quality of glass production. This may be done with electrical energy equivalent to only about half the energy of the flame (combustion) reduction in the furnace.
The heat from dissipation of the current from the electrodes is generated beneath freely advancing floating batch materials downstream of the fill doghouse (charging kiln) of the furnace. Downstream of the floating batch the overhead heat is applied to a freely advancing surface of the molten glass as the glass flow is maintained at the surface rather than being forced under a floater or through a submerged throat. Thus, the full advantages of a strong spring zone flow can be achieved. The molten glass is thoroughly homogenized by the internal shear of adjacent flowing streams within the pool of molten glass, yet the glass is caused to flow in a downstream direction from the spring zone with substantial uniformity of velocity and temperature. As a result, the glass is thoroughly homogenized, refined and made substantially free of ream, striae or cords.
Particulate emission is decreased as flames no long sweep over unmelted batch into the regenerators through the first two ports. Sulfate and other sulfurous emissions also decrease as the temperature of the exposed, unmelted, unreacted batch is kept significantly below its temperature when subjected to impinging flames. Because of this, the amount of salt cake added to the batch can be, and is, reduced.
With the unmelted batch insulating the crown and side walls from the underlying molten glass, the temperatures of the crown, side walls and regenerator packing decrease. As a consequence refractory wear, deterioration and slumping are reduced.
While this invention has been described with reference to particularly preferred embodiments for purposes of illustration, those skilled in the art will recognize that variations may be made without departing from the spirit or scope of this invention as claimed here.
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A horizontal glassmaking furnace adapted for melting glass batch materials by the application of heat to them from overhead flames within the furnace is provided with submerged electric heating electrodes in a region adjacent to where glass batch materials are charged to the furnace and, while overhead flames are reduced or eliminated above the glass batch materials in the vicinity of the electrodes, the glass batch materials are melted from below by action of the electrodes; overhead flames are maintained above exposed molten glass where the glass batch materials have already melted. Discharge of particulate batch materials from the furnace by action of overhead flames is substantially reduced while the thermal efficiency of the furnace is enhanced.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to nucleic acid probes useful for differentiating two closely related species of Campylobacter, C. Fetus, and C. hyointestinalis.
The genus Campylobacter is composed of spirally curved gram negative pathogens with characteristic darting motility but few metabolic characteristics useful in species differentiation. The genus encompasses pathogens of human and veterinary importance, including Campylobacter fetus and Campylobacter hyointestinalis. A vibroid bacterium, Vibrio fetus, has been recognized as the etiological agent of bovine and ovine infertility and abortion. This pathogen has been isolated from the placenta of aborting sheep, stomach contents of aborted fetuses and from blood, and also intestinal contents of infected ewes and cattle. The abortifacient species C. fetus was subsequently subdivided into two subspecies which are differentiated according to their tolerance to 5% glycine. C. fetus subsp fetus is transmitted orally, induces abortion in sheep, and rarely produces septicemia in humans; whereas C. fetus subsp venerealis is exclusively a venereal pathogen of animals. C. fetus subsp fetus replicates at 42° C. and grows in the presence of glycine, whereas the subspecies venerealis replicates at 37° C. and is intolerant of glycine [Smibert, "Genus Campylobacter Seabld and Veron 1963, 907 AL ," pp. 111-118 In N. R. Krieg and J. G. Holt (ed., Bergey's Manual of Systematic Bacteriology, Vol. I, Williams and Wilkins, Baltimore]. C. fetus shares a 16-30% DNA homology with C. hyointestinalis with which it is most closely related. C. hyointestinalis produces H 2 S in triple sugar iron in contrast to C. fetus. The two species may also be distinguished via fatty acid profiles. C. hyointestinalis was first described in association with swine proliferative ileitis and has also been reported in health cattle and as an enteric pathogen of humans.
2. Description of the Prior Art
Nucleic acid hybridization using total genomic DNA has been used in the taxonomy [Fennel et al., J. Clin Microbiol 24:146-148 (1986); Steele et al., J. Clin Microbiol 22:71-74 (1985); Totten et al., J. Infect. Dis. 151:131-139 (1985); Von Sulffen, FEMS Microbiol Lett. 42:129-133 (1987); Chevrier et al., J. Clin. Microbiol. 27:321-326 (1989)] and in the diagnosis [Tomkins et al., Diagn. Microbiol. Infect. Dis. 4:71S-78S (1988) of Campylobacter. Nucleic acid probes have been developed for the genus Campylobacter [Freier et al., Clin. Chem. 34:1176 (1988)]; C. jejuni [Picken et al., Mol. Cel Probes 1:245-259 (1987); Korolik et al., J. Gen Microbiol. 134:521-529 (1988)]; C. hyointestinalis [Gebhart, J. Clin. Microbiol. 27: 2717-2723 (1989)]; and the C. coli--C. jejuni--C. laridis complex [Shrawder et al., Clin. Chem. 34:1176 (1988)].
Although the nucleotide sequences of ribosomal RNAs (rRNA) have been conserved through evolution, mutations have occurred as species diverge [Gray et al., Nucl. Acids Res. 12:5837-5852 (1984); Lane et al., Proc. Natl. Acad. Sci. U.S.A. 82:6955-6959 (1985); Woese et al., Microbiol. Rev. 47:621-629 (1983)]. Many of these changes exist in hypervariable regions. Oligonucleotides complementary to these regions have been synthesized which disciminate very closely related species. The 5S and 16S rRNA sequences of Campylobacter species have been examined for the purpose of studying the phylogeny and diversity of the genus, and partial sequences have been reported [Lau et al., Syst. Appl. Microbiol. 9:231-238 (1987); Romaniuk et al., FEMS Microbiol. Lett. 43:331-335 (1987); Paster et al., Intl. J. Syst. Bacteriol. 38:56-62 (1988); Tompson et al., Intl. J. Syst. Bacteriol. 38:190-200 (1988)]. Though deoxyligonucleotide probes specific for 16S rRNA have been reported for the genus Campylobacter [Moureau et al., J. Clin. Microbiol. 27:1514-1517 (1989); Rashtchian et al., Current Microbiol. 14:311-317 (1987); Romaniuk et al., 1987, supra; Wesley, J. Cell. Biochem. Suppl. 14C:182 (1990)] hypervariable regions between C. fetus and C. hyointestinalis have not been previously identified.
SUMMARY OF THE INVENTION
We have nearly fully sequenced the 16S rRNA in C. fetus and in C. hyointestinalis and have identified a hypervariable region which allows the rRNA of these two species to be distinguished from one another. Based on this information, we have constructed oligodeoxynucleotide probes which are designed to specifically hybridize with DNA or rRNA target sequences associated with the hypervariable region of each of these Campylobacter species. The probes are particularly useful for accelerating the clinical identification of these pathogens from bacterial cultures.
In accordance with this discovery, it is an object of the invention to provide a rapid and effective alternative to conventional biochemical and serological methods of identifying campylobacters.
It is also an object of the invention to provide highly specific and selective oligonucleotide probes useful for clinical diagnosis of diseases induced by C. fetus and C. hyointestinalis.
It is a specific object of the invention to provide an assay for detecting bacterial agents responsible for abortion in livestock and proliferative ileitis in swine.
Other objects and advantages of this invention will become readily apparent from the ensuing description.
GLOSSARY
For purposes of this invention, the following standard abbreviations and terms used herein have been defined below. Also included are a listing of biological materials and reagents mentioned in the specification.
______________________________________ABBREVIATIONS______________________________________ATCC = American Type Culture CollectionAt.sup.32 P = .sup.32 P-labelled adenosine triphosphatebp = base pairsDNA = deoxyribonucleic acidNADC = National Animal Disease Center, Ames, IowaRFLP = restriction fragment length polymorphismRNA = ribonucleic acidrRNA = ribosomal ribonucleic acidss-rRNA = single-stranded ribosomal ribonucleic acidSDS = sodium dodecyl sulfateVPI = Virginia Polytechnic Institute______________________________________
TERMS
DNA or RNA sequence: a linear series of nucleotides connected one to the other by phosphodiester bonds between the 3' and 5' carbons of adjacent pentoses.
hybridization: the pairing together or annealing of complementary single-stranded regions of nucleic acids to form double-stranded molecules.
hypervariable region: region within highly conserved 16S rRNA to which nucleotide changes occur most frequently.
nucleotide: a monomeric unit of DNA or RNA consisting of a sugar moiety (pentose), a phosphate, and a nitrogenous heterocyclic base. The base is linked to the sugar moiety via the glycosidic carbon (1' carbon of the pentose) and that combination of base and sugar is a nucleoside. The base characterizes the nucleotide. The four DNA bases are adenine ("A"), guanine ("G"), cytosine ("C") and thymine ("T"). The four RNA bases are A, G, C and uracil ("U").
oligonucleotide: a linear series of 2-100 deoxyribonucleotides or ribonucleotides connected one to the other by phosphodiester bonds between the 3' and 5' carbons of adjacent pentoses.
oligonucleotide probe: a single-stranded piece of DNA or RNA that can be used to detect, by hybridization or complementary base-pairing, a target nucleic acid sequence which is homologous or complementary.
sequence: two or more DNA or RNA nucleotides in a given order.
stringency: refers to the conditions under which hybridization takes place. At high stringency only exact matches of DNA and RNA will hybridize stably. Under low stringency, nonhomologous sequences may hybridize.
DETAILED DESCRIPTION OF THE INVENTION
In preparation for developing oligonucleotide probes of the invention, we determined nearly the full nucleotide sequences of the 16S rRNA molecule of C. fetus subsp fetus (ATCC 27274), C. fetus subsp venerealis (ATCC 19438) and C. hyointestinalis (NADC 2006 and ATCC 35217). Upon comparison of these sequences, regions of the C. fetus species 16S rRNA molecule that differed from analogous regions of the C. hyointestinalis 16S rRNA were identified. One such region, hereafter referred to as the hypervariable region, was selected. This region is represented by the ss-rRNA sequences of the aforementioned deposit strains shown in Table III and in the appended Sequence Listing as SEQ ID NOS. 1-4. In Table III, nucleotide mismatches amongst the strains are underlined.
A strategy for constructing a probe within the scope of the invention is initiated by predetermining the probe's length. It is envisioned that probes useful herein would range in size from about 10 to 50 bases, with the preferred size being about 15 to 30 bases. A sequence of the predetermined length, occurring within the 16S rRNA and including at least one of the base mismatches in the hypervariable region is then selected. In order to avoid the need for highly stringent conditions during hybridization, the selected sequence preferably includes at least two base mismatches. Optimally, the probe would include all eight of the recognized mismatches in the hypervariable region. The nucleotide sequence complementary to the selected rRNA sequence is thereafter determined, and the oligodeoxyribonucleotide probe is synthesized as the inverse of the complementary sequence. In this way, the probe is in correct orientation for binding to native DNA or rRNA in samples to be assayed.
Given below in the Sequence Listing as SEQ ID NO. 5 is the base sequence corresponding to the inverse of the complement of the C. fetus subsp venerealis rRNA or C. hyointestinalis extending 50 bases upstream and 40 bases downstream from the hypervariable region. In SEQ ID NO. 5, the IUPAC code N, representing any nucleotide, has been used whenever a mismatch between the sequences originating from C. fetus or C. hyointestinalis occurred at a given position or when the nucleotide at a given position was undetermined for both species The sequences of probes encompassed by the invention can be ascertained directly from SEQ ID NO. 5 in conjunction with SEQ ID NOS. 1-4. Examples of such probes are represented as SEQ ID NOS. 6-8, discussed further below.
Under appropriately stringent conditions, a probe of the invention will bind only to DNA or rRNA of the Campylobacter species it was designed to detect. This specificity makes these probes useful for the unequivocal detection of C. fetus or C. hyointestinalis in complex samples such as fecal material.
The derivation of probes as outlines above has several advantages over cloned genomic DNA probes. When the target of the probe is rRNA, increased sensitivity is obtained because the rRNA is present in up to 10,000 copies per cell as opposed to only 1-10 gene copies per cell. Also short oligonucleotide probes can be used with substantially reduce the hybridization time. This results in a highly sensitive and specific test that can be completed in 5 days or less.
These probes are useful in a variety of hybridization formats. The approach which is most readily applied to a laboratory setting is the colony blot, in which the probe is reacted with bacterial colonies. The slot blot technique uses either bacterial colonies which are subsequently lysed, or else chromosomal DNA which may be harvested with commercially available DNA extraction kits. The Southern blot hybridization protocol would be useful for deducing taxonomic relationships.
In addition, the probes of the invention can be used to differentiate between Campylobacter species based on RFLP analysis. DNA isolated from bacteria are digested with restriction endonucleases, the fragments are separated by electrophoresis through an agarose gel, transferred to a solid support, and hybridized with the oligonucleotide probe. When probed in this way, the Campylobacter species can be differentiated based on the positions of the DNA bands that hybridize with the probe. This application is epidemiologically useful for following the transmission of a particular organism.
To enable detection, the probes may be bound to a radioactive, enzymatic, or organic label by any conventional procedure in the art. For instance, by leaving the 5'--OH end nonphosphorylated during construction, the probes are readily end-labelled using T4 polynucleotide kinase and γ AT 32 P as described in Example 2.
The following examples are intended only to further illustrate the invention and are not intended to limit the scope of the invention which is defined by the claims.
EXAMPLE 1
Selection of Bacterial Strains and Growth Conditions
Bacterial strains were obtained from the American Type Culture collection (ATCC), National Animal Disease Center (NADC), and Virginia Polytechnic Institute (VPI) collections. The following ATCC reference strains of Campylobacter were evaluated: C. cinaedi ATCC 35683, C. coli ATCC 33559, C. concisus ATCC 33237, C. cryaerophila ATCC 43158, C. faecalis ATCC 33709, C. fenneliae ATCC 35684, C. fetus subsp fetus ATCC 27374, C. fetus subsp venerealis ATCC 19438, C. hyointesitinalis ATCC 35217, C. laridis ATCC 35221, C. jejuni ATCC 33560, C. mucosalis ATCC 43264, C. nitrofigilis ATCC 33309, C. sputorum subsp. bubulus ATCC 33562, and C. sputorum subsp sputorum ATCC 35980. The C. upsaliensis strain (D1914) was obtained from the Center for Disease Control, Atlanta, Ga.
Field isolates of C. fetus (n=53) and C. hyointestinalis (n=55) examined in this study are shown in Tables I and II, respectively. Isolates were characterized as C. fetus based on characteristic morphology, motility, site of isolation from the host, growth at 42° C., and failure to generate H 2 S. Isolates of C. hyointestinalis were confirmed as such by H 2 S production, tolerance of glycine, sensitivity to nalidixic acid and cephalothin and fatty acid profiles. In addition, serologic cross-reactivity with C. fetus was evaluated in a microtiter agglutination assay [Firehammer et al., Amer. J. Vet. Res. 47:1415-1418 (1986)]. Two strains of C. jejuni (NADC 1829 and NADC 1990) were also included as negative controls.
Bacteria were grown on brain heart infusion agar (BHIA) with 10% defibrinated bovine blood and incubated microaerophilically (10% CO 2 and 90% air; 72 hr at 37° C.).
EXAMPLE 2
16S Ribosomal RNA Sequence Analysis
RNA was isolated and partially purified as described by Paster et al. [1988, supra]. Complete 16S ribosomal RNA sequences were determined for C. hyointestinalis (ATCC 35217 and NADC 2006), C. fetus subsp fetus (ATCC 27374 and VPI H641), and for C. fetus subsp venerealis (ATCC 19438). These sequences were compared with published partial sequences of Campylobacter concisus, C. fetus subsp fetus, C. jejuni, C. coli, C. laridis, C. sputorum, C. pylori, a campylobacter of ferrets, Bacterioides gracilis, B. ureolyticus, Wolinella recta, W. curva, W. succinognes, Escherichia coli, Citrobacter freundii, Proteus vulgaris, and the unpublished sequence of Flexispira rappini. The computer program of Paster et al. [1988, supra] was used for data entry, editing, sequence alignment, secondary structure comparison, homology matrix generation, and dendrogram construction for 16S rRNA data. Nucleic acid sequences which were selected for probes were identified by alignment of 16S rRNA sequence data, identification of common bases and selection of regions where mismatches occurred. Commercially prepared oligonucleotides (Synthecell, Gaithersburg, Md.) were end-labelled with 32 P γ ATP by the T4 polynucleotide kinase reaction as described [Richardson, Proc. Nucl. Acid Res. 2:815 (1971)].
A total of 1413 bases were sequenced for 16S ribosomal RNA of C. fetus and C. hyointestinalis. Alignment of nucleic acids indicated that a single base mismatch (position 811) differentiated C. fetus subsp fetus from the subspecies venerealis. In contrast, a 28 oligonucleotide difference distinguished C. fetus from C. hyointestinalis. Based on sequence data, it was demonstrated that C. fetus subsp fetus shared a 99.8% to 100% sequence homology with the subspecies venerealis and a 98% sequence identity with C. hyointestinalis.
A region of 8 mismatches (from position 1017 to 1046) was identified. The rRNA sequence data for this hypervariable region for each of C. fetus subsp venerealis (ATCC 19438), C. fetus subsp fetus (ATCC 27374), C. hyointestinalis (NADC 2006), and C. hyointestinalis (ATCC 35217) are given in Table III and also in the Sequence Listing as SEQ ID NOS. 1-4, respectively. Two C. fetus-specific probes, a 17-oligodeoxynucleotide probe (5'CTC-AAC-TTT-CTA-GCA-AG 3'; SEQ ID NO. 6) and a 29-oligodeoxynucleotide probe (5'CTC-AAC-TTT-CTA-GCA-AGC-TAG-CAC-TCT-CT-3'; SEQ ID NO. 7) were synthesized from the hypervariable region. These probes do not encompass the single base mismatch which exists between C. fetus subsp fetus and C. fetus subsp venerealis. Also a 29-oligodeoxynucleotide probe (5'-CAC-TAA-TTT-CIT-GTA-AAC-AAG-CAC-TAT-CT-3'; SEQ ID NO. 8) specific for C. hyointestinalis was synthesized.
EXAMPLE 3
To determine the specificity for the appropriate microbe, the three probes prepared in Example 2 were tested in a colony blot hybridization format against reference strains of 16 Campylobacter species and subspecies as follows.
Colony Blot Hybridization
A nylon membrane ("GeneScreen," NEN Research Products, Dupont deNemours and Company, Inc., Boston, Miss.) was gently pressed over bacterial colonies (3-4 days old) grown on BHIA containing 10% defibrinated bovine blood. After a minimum of 1 hr the membrane was denatured (0.5M NaOH, 1.5M NaCl), neutralized (1M tris, 3M NaCl, pH 5.5) and UV crosslinked to covalently bind the DNA to the membrane filters. Hybridization was carried out at (37° C. for 18 hr) in 6X SSC (SSC is 0.15M NaCl, 0.015M Na citrate, pH 7.0), 5X Denhardt's solution (0.1% Ficoll, 0.1% polyvinylpyrrolidone, 0.1% bovine serum albumin), 0.5% SDS, and 100 μg/ml of sonicated denatured calf thymus DNA. The hybridization solution contained 10 6 cpm of the appropriate end-labelled 32 P oligonucleotide probe. After incubation, filters were washed once briefly in 2X SSC-0.1% SDS at room temperature, followed by two stringency washes. For C. fetus (17-mer) stringency washes were completed in saline sodium citrate (1X SSC, 37° C., 1 hr) whereas the 29-mer specific for C. fetus required higher stringency conditions (47° C. in 0.1X SSC). For C. hyointestinalis the stringency washes were performed in 6X SSC (50° C., for 1 hr). Dried filters were exposed to Kodak "X-Omat" film with two intensifying screens (-80° C., 1 day).
As shown in Table IV, the two C. fetus specific oligonucleotides hybridized only with the reference strains of C. fetus subsp fetus (ATCC 19438) and C. fetus subsp venerealis (ATCC 27374). No reaction was seen with any of the other reference strains of Campylobacter, including the phylogenetically closely related C. hyointestinalis. The C. hyointestinalis specific probe hybridized only with the colony blots of the C. hyointestinalis reference strain (ATCC 35217). No cross reaction was observed with the closely related C. fetus strains (ATCC 19438 and ATCC 27374).
EXAMPLE 4
Specificity of each of the C. fetus probes was evaluated further in a slot blot format against genomic DNA of field strains as follows.
Slot Blot Hybridization
For slot blot hybridization, high molecular weight genomic DNA was extracted from bacterial cells as described by Wesley et al. [Amer. J. Vet. Res. 50:807-813 (1989)]. A series of preliminary experiments was carried out to determine the appropriate hybridization and washing conditions to maximize the signal to background ratio. Typically, 2 μg/well of Campylobacter genomic DNA was applied to a "GeneScreen" nylon membrane (NEN Research Products, Dupont deNemours and Company, Inc., Boston, Mass.) in a slot-blot apparatus (Biorad, Richmond, Calif.). The DNA was denatured, neutralized, and UV crosslinked as described above for colony blot hybridization. Prehybridization was carried out for 3 hr at 37° C. in 6X SSC. 5X Denhardt's solution, 0.5% SDS, and 100 μg/ml of sonicated denatured calf-thymus DNA. Hybridization and stringency washes were conducted as described above for colony blot hybridization. Radiolabelled probes which hybridized to target nucleic acids were visualized by autoradiography with Kodak "X-Omat" film and DuPont intensifying screens (=80° C. 1 day).
The C. fetus-specific probes hybridized equally well with genomic DNA of 49 of 53 field strains of C. fetus of bovine, human, or ovine origin. In a typical hybridization, the C. fetus-specific oligonucleotides hybridized equally well with isolates of the subspecies fetus (ATCC 27374, NADC 1992) and venerealis (ATCC 19438, NADC isolates 1986, 1987, 1988, 1989, 1991). No hybridization occurred with genomic DNA isolated from either C. hyointestinalis (ATCC 35217) or from C. jejuni (NADC 1990). The field strains which did not hybridize were identified as follows. No hybridization occurred with two bovine isolates (NADC 5-DLF and NADC 27-J46), which, after Hha I digestion, exhibited a restriction enzyme pattern atypical of C. fetus and were subsequently identified as C. sputorum bubulus (data not shown). A bovine isolate (NADC 2460), which failed to react with the C. fetus probe did, however, hybridize with the oligonucleotide for C. hyointestinalis and was subsequently identified biochemically as such. An ovine isolate (NADC 2462) did not react with the C. fetus probe and was reidentified as a C. jejuni strain, which was inadvertently included in these studies.
The C. hyointestinalis-specific probe was appraised using genomic DNA of 55 field isolates of C. hyointestinalis. A typical hybridization result indicated that this probe reacted with the prototype reference strain and 14 of 18 field strains, but not with C. fetus subsp fetus (ATCC 27374), subsp venerealis (ATCC 19438), or C. jejuni. Three porcine field isolates (1585-G5, 1585-G7, and 1585-G8), which were initially identified as C. hyointestinalis based on anatomical site of recovery and weak H 2 S production, did not react with the probe under stringency conditions (6X SSC, 50° C.), used in these studies. However, relaxing the stringency conditions (4X SSC, 45° C.), resulted in a weak signal. Restriction enzyme analysis has shown these to be clones of a single strain. Isolate NADC 1705, which did not react with the C. hyointestinalis probe, was subsequently identified as C. fetus. In further assays, other isolates which did not hybridize with the C. hyointestinalis probe were identified as follows. NADC isolates 1589.2, 1705, and 2029 failed to hybridize with the oligonucleotide for C. hyointestinalis, but did react with the C. fetus specific probe and were subsequently verified as such biochemically. The human strains NADC isolate 1997, which was initially described as an atypical Campylobacter-like organism (CLO), and isolate NADC 2020 failed to react with probes for either C. hyointestinalis or for C. fetus. Isolate NADC 2020 was subsequently identified biochemically as C. jejuni; isolate NADC 1997 was not identified further.
EXAMPLE 5
The three probes described in Example 2 were evaluated in Southern blot hybridization of genomic DNA extracted from field isolates and cleaved with the restriction endonuclease Bg1 II. This assay was performed as follows.
Southern Blot Hybridization
Genomic DNA was digested with Bg1 II and restriction fragments size separated in 0.6% agarose gels (60V, 18 hr), blotted onto "GeneScreen" nylon membranes using the method of Southern (1975), and UV crosslinked as described by Church et al. [Proc. Natl. Acad. Sci. U.S.A. 81:1991-1995 (1984)]. To detect the presence of 16S rRNA genes, nylon filters were prehybridized (3 hr) and then hybridized (18 hr, 37° C.) with 5×10 6 cpm of the appropriate 32 p end-labelled oligonucleotide probe as described above. Membranes were washed once in 2X SSC, 0.1% SDS at room temperature. For C. fetus (17-mer) two stringency washes were completed in saline sodium citrate (1X SSC, 37° C., 1 hr)whereas the 29-mer required stringency washes at 47° C., in 0.1X SSC. Stringency washes for the C. hyointestinalis oligonucleotide were performed in 4X SSC (45° C., 1 hr). Dried filters were exposed to Kodak "X-Omat" film with two intensifying screens (-80° C., 2-7 days).
Nucleic acid sequences homologous with the oligonucleotide probes specific for the C. fetus 16S rRNA genes were localized within no more than three restriction fragments (9.0, 7.7, 7.0 kb). Hybridization occurred with two common restriction fragments (9.0 7.7) whereas reactivity with a third smaller restriction fragment (7.0 kb) was occasionally noted. Southern blot hybridization of C. hyointestinalis strains digested with the endonuclease Bg1 II and probed with the C. hyointestinalis specific oligonucleotide indicated that sequences encoding 16S rRNA genes were localized within no fewer than three restriction fragments: 10.1, 8.2, and 7.2 kb.
It is understood that the foregoing detailed description is given merely by way of illustration and that modification and variations may be made therein without departing from the spirit and scope of the invention.
TABLE I______________________________________Strains of Campylobacter fetusSource No. of Strains NADC strain identification______________________________________Human 9 2591, 2592, 2954, 2595, 2596, 2597, 2598, 2599, 2600Bovine 42 5-DLF.sup.a, 6-RCM, 7-9C30, 9-DLF, 10-71, 11-46, 13-G26, 14-K287, 15-K6, 18-F91, 19-L53, 21-A11, 21-H23, 21-G36, 21-G83, 22, 25-G28, 27-J46.sup.a, 44-77, 1289, 1826, 1827, 1828, 1830, 1831, 1832, 1833, 1986, 1987, 1988, 1989, 1991, 1992, 2456, 2457, 2458, 2459, 2460.sup.b, 2461, 2646, 2705, 2716Ovine 2 2462.sup.c,2642______________________________________ .sup.a Isolates 5DLF and 27J46 failed to hybridize with the C. fetus prob and were subsequently reidentified as C. sputorum subsp bubulus. .sup.b Isolate 2460 failed to hybridize with the C. fetus probe but did react with the probe for C. hyointestinalis. .sup.c Isolate reidentified as C. jejuni.
TABLE II______________________________________Strains of C. HyointestinalisSource No. of Strains NADC strain identification______________________________________Porcine 21 1585-G4, 1585-G5, 1585-G6, 1585-G7, 1585-G8, 1585-G9, 1705.sup.a, 1819, 1821, 1825, 1916, 1917, 1919, 1920, 2000, 2001, 2002, 2027, 2028, 2034, 2641Human 21 1996, 1997.sup.b, 1998, 2006, 2007, 2008, 2009, 2018, 2019, 2020.sup.b,2021, 2022, 2023, 2024, 2025, 2026, 2037, 2261, 2262, 2263, 2264Bovine 13 1492, 1493, 1587, 1589.2.sup.a, 1592, 1593, 2029.sup.a, 2031, 2032, 2033, 2035, 2036, 2038______________________________________ .sup.a NADC isolates 1589.2, 1705, and 2029 hybridized with the probe specific for C. fetus and failed to react with the C. hyointestinalis-specific oligomer. .sup.b NADC isolates 1997, 2020 failed to react with the probe for either C. fetus or C. hyointestinalis. Isolate NADC 2020 was identified as C. jejuni; isolate NADC 1997 was not identified further.
TABLE III__________________________________________________________________________16S rRNA from Campylobacter Species__________________________________________________________________________C. fetus subsp venerealis AGA .sub.-- GAGUGCU .sub.-- AG .sub.-- CUU .sub.-- GC .sub.-- UAG AAA .sub.-- GU .sub.-- UG .sub.-- AGA(ATCC 19438)C. fetus subsp fetus AGA .sub.-- GAGUGCU NG .sub.-- CUU .sub.-- GC .sub.-- UAG AAA .sub.-- GU .sub.-- UG .sub.-- AGA(ATCC 27374)C. hyointestinalis AGA .sub.-- UNGUNCU NG .sub.-- UUUNCNAG AAA .sub.-- UUNG .sub.-- UGA(NADC 2006)C. hyointesinalis AGA .sub.-- UNGUNCU UG .sub.-- UUU .sub.-- AC .sub.-- AAA .sub.-- UU .sub.-- AG .sub.-- UGA(ATCC 35217)POSITION 5' 1017 1046 3'__________________________________________________________________________
TABLE IV______________________________________Colony Blot Hybridization C. fetus C. hyointestinalisSpecies (17-mer, 29-mer) (29-mer)______________________________________C. cineadi ATCC 35683 - -C. coli ATCC 33559 - -C. concisus ATCC 33237 - -C. cryaerophila - -ATCC 43158C. faecalis ATCC 33709 - -C. fenneliae ATCC 35684 - -C. fetus subsp + -fetus ATCC 27374C. fetus subsp + -venerealis ATCC 19438C. hyointestinalis - +ATCC 35217C. jejuni ATCC 33560 - -C. laridis ATCC 35221 - -C. mucosalis ATCC 43264 - -C. nitrofigilis ATCC 33309 - -C. sputorum subsp - -bubulus ATCC 33562C. sputorum subsp - -sputorum ATCC 35980C. upsaliensis D1914 - -______________________________________
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 8(2) INFORMATION FOR SEQ ID NO:1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 120 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: rRNA(iii) HYPOTHETICAL: NO(iv) ANTI-SENSE: NO(vi) ORIGINAL SOURCE:(A) ORGANISM: Campylobacter fetus(B) STRAIN: fetus(C) INDIVIDUAL ISOLATE: ATCC 27374(ix) FEATURE:(A) NAME/KEY: miscdifference(B) LOCATION: replace(51..80, "")(D) OTHER INFORMATION: /note="bases 51-80 constitute ahypervariable region corresponding to bases1017-1046 of the 16S rRNA"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:ACGCGAAGAACCUUACCUNGGCUUNAUAUCCAACUNAUCUCUUAGAGAUNAGAGAGUGCU60NGCUUGCUAGAAAGUUGAGACAGGUGCUGCACGGCUGUCGUCAGCUCGUGUCGUGAGAUG120(2) INFORMATION FOR SEQ ID NO:2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 120 base pairs (B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: rRNA(vi) ORIGINAL SOURCE:(A) ORGANISM: Campylobacter fetus(B) STRAIN: venerealis(C) INDIVIDUAL ISOLATE: ATCC 19438(ix) FEATURE:(A) NAME/KEY: miscdifference(B) LOCATION: replace(51..80, "")(D) OTHER INFORMATION: /note="bases 51-80 constitute ahypervariable region corresponding to bases1017-1046 of the 16S rRNA"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:ACGCGAAGAACCUUACCUGGGCUUGAUAUCCAACUNAUCUCUUAGAGAUAAGAGAGUGCU60AGCUUGCUAGAAAGUUGAGACAGGUGCUGCNCGGCUGUCGUCAGCUCGUG UCGUGAGAUG120(2) INFORMATION FOR SEQ ID NO:3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 120 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: rRNA(vi) ORIGINAL SOURCE:(A) ORGANISM: Campylobacter hyointestinalis(C) INDIVIDUAL ISOLATE: NADC 2006(ix) FEATURE: (A) NAME/KEY: miscdifference(B) LOCATION: replace(51..80, "")(D) OTHER INFORMATION: /note="bases 51-80 constitute ahypervariable region corresponding to bases1017-1046 of the 16S rRNA"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:ACGCGAAGAACCUUACCUNGGNUUNAUAUCCUNAUNACAUCUUAGAGAUNAGAUNGUNCU60NGUUUNCN AGAAAUUNGUGACAGGUGCUGCACGGCUGUCGUCAGCUCGUGUCGUGAGAUG120(2) INFORMATION FOR SEQ ID NO:4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 120 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: rRNA(vi) ORIGINAL SOURCE:( A) ORGANISM: Campylobacter hyointestinalis(C) INDIVIDUAL ISOLATE: ATCC 35217(ix) FEATURE:(A) NAME/KEY: miscdifference(B) LOCATION: replace(51..80, "")(D) OTHER INFORMATION: /note="bases 51-80 constitute ahypervariable region corresponding to bases1017-1046 of the 16S rRNA "(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:ACNNGNAGAACCUUACCUNGGCUUNAUAUCC UNAUNACAUCUUAGAGAUAAGAUNGUNCU60UGUUUACAAGAAAUUAGUGANAGGUGCUGCNCGGCUGUCGUCAGCUCGUGUCGUGAGAUG120(2) INFORMATION FOR SEQ ID NO:5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 120 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single (D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to rRNA(vi) ORIGINAL SOURCE:(A) ORGANISM: Campylobacter(ix) FEATURE:(A) NAME/KEY: miscdifference(B) LOCATION: replace(41..70, "")(D) OTHER INFORMATION: /note="bases 41-70 arecomplementary to bases 51-80, resp. in SEQ ID NOS.1-4; bases 43, 45, 47, 53, 55, 58, 60, and 67 are(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:CATCTCACGACACGAGCTGACGACAGCCGNGGAGCACCTNTCNCNANTTTCTNGNAANCN60AGNACNNTCTNATCTCTAAGANNTNANNNGGATATNAANCCNAGGTAAGGTTCTNCNNGT120(2) INFORMATION FOR SEQ ID NO:6:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 17 base pairs (B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to rRNA(ix) FEATURE:(A) NAME/KEY: miscfeature(B) LOCATION: 1..17(D) OTHER INFORMATION: /product="probe"/note="corresponds to bases 42-58 of SEQ ID NO 5"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:CTCAACTTTCTAGCAAG 17(2) INFORMATION FOR SEQ ID NO:7:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 29 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to rRNA(ix) FEATURE:(A) NAME/KEY: miscfeature (B) LOCATION: 1..29(D) OTHER INFORMATION: /product="probe"/note="corresponds to bases 42-70 of SEQ ID NO.5"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:CTCAACTTTCTAGCAAGCTAGCACTCTCT29(2) INFORMATION FOR SEQ ID NO:8:(i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 29 base pairs(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D) TOPOLOGY: linear(ii) MOLECULE TYPE: cDNA to rRNA(ix) FEATURE:(A) NAME/KEY: miscfeature(B) LOCATION: 1..29(D) OTHER INFORMATION: /product="probe"/note="corresponds to bases 42-70 of SEQ ID NO. 5"(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:CACTAATTTCTTGTAAACAAGCACTATCT29
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Single-stranded DNA probes complementary to a hypervariable region of Campylobacter 16S rRNA are useful in distinguishing species of this pathogen from one another. The probes find practical application in diagnosing human and animal diseases caused by this organism from clinical samples, such as fecal material. They are also useful in differentiating Campylobacter species based on RFLP analyses.
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BACKGROUND OF THE INVENTION
1) Field of the Invention
The field of this invention relates to electrolysis and more particularly to an electrolysis machine that provides for quick removal of hair.
2) Description of the Prior Art
Removal of unwanted hair on male and female humans has long been known. Removal of unwanted hair is usually accomplished by means of electrolysis. The prime objective of electrolysis is to permanently remove the hair after a single application. This is normally accomplished by destroying the hair follicle from which the hair grows. This destruction of the hair follicle is to be accomplished with a minimum amount of tissue destruction and also with a minimum amount of pain during application of the technique. Electrolysis is normally applied by means of an electrologist.
For a great many years, electrolysis used only direct current. The direct current tends to flow more quickly to areas where it is moist, namely the lower portion of the hair follicle.
This results in the producing of a chemical reaction, the main product of which is sodium hydroxide or lye. This sodium hydroxide is caustic and literally eats away at the hair.
Direct current electrolysis produces a low rate of regrowth of the hair which is quite advantageous. However, direct current has certain disadvantages in that it takes a substantial period of time (one to three minutes) for each hair follicle. Therefore, considering the wages of an electrologist, direct current electrolysis is quite expensive. Also, direct current electrolysis is somewhat painful to the patient.
In recent years, a new electrolysis technique, called "thermolysis" became prevalent. Thermolysis is used with a probe in the same manner as the direct current electrolysis uses a probe. However, with thermolysis, instead of direct current, a high frequency sinusoidal voltage is injected into the follicle. The radio frequency tends to physically cook the follicle thereby desiccating such.
Thermolysis has the primary advantage in that it is exceedingly fast and can be even faster than a tenth of a second for high intensity bursts of radio frequency energy. Thermolysis also has the advantage that it is simple to train an operator to understand the technique. Most often, thermolysis takes three to five seconds, which is an incredible increase over the one to three minutes, which is necessary with direct current electrolysis.
Thermolysis also has the additional advantage in that the heating pattern begins at the tip of the probe and spreads with time. This is called the "point affect" and causes the follicle destruction to begin at the very bottom, which is a desirable location to achieve complete follicle destruction. The disadvantage of thermolysis is that the heating pattern is narrow. It has been generally found that thermolysis has a low reliability factor when used on heavier curly hair. This is due to the fact that the heavy hair follicles are too wide for the heating pattern. In relation to curly hair, the follicle itself will curl away from the probe and thereby leave hair follicle areas which have not been destroyed. Any portion of the hair follicle that has not been destroyed will be capable of regrowing.
Within the last few years, a new technique came to pass which has been called the "blend technique." This blend technique combines a direct current technique with the radio frequency technique. The radio frequency technique causes heat in the follicle which increases the rate of chemical action for the direct current. The heat also tends to open the tissue allowing the lye to penetrate the tissue much more quickly. The result is reliability and low regrowth rates of the direct current technique has been obtained with a substantially shorter period of time.
Normal treatment time for the blend technique is between twenty and fifty seconds. This is considerably longer than the thermolysis technique by itself, but also substantially shorter than direct current electrolysis by itself. For discussion of the blend technique, reference is to be had to U.S. Pat. No. 4,598,709, entitled ELECTROLYSIS MACHINE, which has been issued to a Margaret M. Smith who is one of the inventors of the present application.
One of the disadvantages of the prior art electrolysis machines is that they use only a single probe. Inherently, there is a certain time that is required in order to effect destruction of the hair follicle. If only a single probe is used, then only a single hair follicle is being destroyed within that given period of time. If the electrolysis machine includes a plurality of probes, then the electrologist can use a plurality of probes within that same period of time thereby effecting removal of a plurality of hairs rather than a single hair. Therefore the use of a multi-probe machine is definitely more cost effective. Multi-probe electrolysis machines have generally been known in the prior art. However, these machines have only utilized direct current. It has not been known to utilize a multi-probe machine that uses both direct current and radio frequency.
Previous to the present invention, it has only been known to construct an electrolysis machine as a single unit which is locatable on a supporting surface such as a table or desk. The electrologist is constantly setting dials on the machine and referring to the meter or meters on the machine to insure that the correct voltage and current is being transmitted to the patient. It is desirable to have the machine maneuvered to be located directly in front of the electrologist during usage thereby making the machine readily observable as the electrologist works on the patient.
SUMMARY OF THE INVENTION
An electrolysis machine that is constructed of two separate units comprising a main unit and an arm unit. The main unit is to be positioned in a fixed location on a desk or table. The arm unit is to be mounted on an extendable adjustable arm which is to permit maneuverability of the arm unit to any desired position directly adjacent the electrologist and the patient. The arm unit has mounted thereon a plurality of probes with generally six in number being preferred. The circuitry within the electrolysis machine utilizes both direct current and radio frequency. The direct current is to be adjustable to different levels between zero and one milliamp. Radio frequency can be preset to a given level such as twenty-five volts, or can be adjustable to different levels. The electrologist is able to select only the direct current or can select the direct current combined with the radio frequency. Once a probe establishes contact with the patient, there is a short time period, such as a couple of seconds, to insure that the probe is then correctly positioned in conjunction with the hair follicle. The selected current is then transmitted to the probe for a preselected period of time which will generally be between twenty and fifty seconds. During the transmission of the electrical energy to this probe, the electrologist is able to install other probes to effect removal of other hairs. When the first installed probe is deactivated, the electrologist can then remove that probe and then utilize it in conjunction with another hair follicle. Once the electrical circuit is established with the patient, the current transmitted to the patient is permitted to rise slowly over a two second time period to its preset level thereby minimizing the creation of any pain in using of the electrolysis machine of the present invention. The electrolysis machine can also be used as a skin conditioning apparatus since the circuitry includes an anaphoresis circuit and a cataphoresis circuit. When utilizing the electrolysis machine as a skin conditioning apparatus, probes are not used but instead a separate applying tool is connected directly to the main unit of the electrolysis machine.
The primary objective of the present invention is to construct an electrolysis machine which can be maneuvered to different positions so as to be readily accessible to an electrologist during usage with patient.
Another objective of the present invention is to construct an electrolysis machine which utilizes a plurality of probes which can be installed at the same time so as to effect removal of a plurality of hairs within the shortest period of time.
Another objective of the present invention is to construct an electrolysis machine which produces the level of current to the probe only upon the proper electrical connection being achieved by the probe.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention depicting a typical installation of the machine;
FIG. 2 is a front elevational view, enlarged in relation to FIG. 1, of the arm unit of the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 3 is a side elevational view of the arm unit of the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention taken along line 3--3 of FIG. 2;
FIG. 4 is an enlarged view of the main unit of the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 5 is an electrical schematic of the power supply circuitry utilized in conjunction with the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 6 is an electrical schematic of the electrical grounding of the chassis of the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 7A and FIG. 7B constitute an electrical schematic of the control circuitry utilized in conjunction with the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 8 is an electrical schematic of a further portion of the control circuitry utilized in conjunction with the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 9 is an electrical schematic for the direct current portion of the circuitry utilized in conjunction with each probe of the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 10A is an electrical schematic for the radio frequency portion of the circuitry utilized in conjunction with probes 1, 2 and 3 mounted within the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 10B is an electrical schematic for the radio frequency portion of the circuitry utilized in conjunction with probes 4, 5 and 6 mounted within the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 11 is an electrical schematic of a portion of the direct current circuitry that can be utilized to adjust the value of direct current that is transmitted to the patient;
FIG. 12 is an electrical schematic of a further portion of the control circuitry utilized in conjunction with the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention;
FIG. 13 is an electrical schematic of a further portion of the direct current control circuitry utilized within the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention; and
FIG. 14 is an electrical schematic of a further portion of the radio frequency circuitry that is utilized in conjunction with the MULTI-PROBE BLEND ELECTROLYSIS MACHINE of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring particularly to the drawings, there is shown in FIG. 1 a MULTI-PROBE BLEND ELECTROLYSIS MACHINE 12 of this invention. The MULTI-PROBE BLEND ELECTROLYSIS MACHINE 12 is composed of a main unit 184 and an arm unit 188. The main unit 184 is mounted within a rigid wall chassis 190 which is basically in the shape of a rectangular box. The arm unit 188 also is enclosed within a chassis 192 which is in the shape of a rectangular box. The appropriate electrical connection provided by electrical wires 194 are to connect to the main unit 184. The main unit 184 is to be connected to a source of electrical power which is not shown. The electrical wires 194 are mounted within and extend through arm members 196 and 198. Arm member 196 is pivotly connected to arm member 198 by means of a pivot joint 252. The arm member 198 is pivotly connected by means of a pivot joint 288 to a base mount 296. The base mount 296 is fixedly mounted onto a supportive surface such as a table 298. The main unit 184 is also shown mounted on the table 298.
The front panel of the chassis 190 of the main unit 184 has mounted therein jacks 327, 381 and 383. The jack 327 is to connect with an electrical wire (not shown). This wire will terminate in a grasping end which is to be electrically conductive. When the probe wires 152, 154, 156, 158, 160 and 162 are used to connect with the patient, that patient will also grasp the grasping end of the wire which connects to the jack 327. The jacks 381 and 383 are used solely for the purpose of conditioning of the skin. This conditioning is to be in the form of an electrically stimulating applicator (not shown) which is to be connected to the jack 381. An electrical wire (not shown), similar to the wire which connects to jack 327, is to be mounted in conjunction with the jack 383 and is to be held by the patient. The holding of the wire that connects to jack 383 will complete the circuit through the patient for the electrical stimulation. This electrical stimulation can be either in the form of a positive flow of current which is called cataphoresis or negative flow of current which is called anaphoresis. Selecting of anaphoresis or cataphoresis is strictly at the option of the electrologist and is selected by the electrologist depressing button 164 which connects to switch 402. Activation or turning on of the main unit 184 is accomplished by the electrologist depressing button 324 which closes switch 10.
Mounted on the chassis 192 of the arm unit 188 are a pair of handles 440 and 442. The handles 440 and 442 are to facilitate manual movement of the arm unit 188 to various different locations in close proximity to the main unit 184 but spaced therefrom. The pivot joints 252 and 288 of the arm members 196 and 198 are constructed so that when the arm unit 188 is released, it will remain in the released position and not move therefrom. The arm unit 188 is constructed to be relatively light in weight, generally no more than a few pounds in weight.
The front panel of the chassis 192 includes a DC meter panel 444. Within that DC meter panel 444 is the DC meter 462. This will inform the electrologist the amount of direct current that is being transmitted to the patient. The setting of the amount of the direct current between zero and one milliamp is to be selected by turning of the knob 446 which controls the direct current setting potentiometer 342. The amount of time that the current is to be applied to the patient is also to be selected in seconds by turning of the knob 448. Knob 448 operates the timing potentiometer 272. The operator also has the option of selecting only the direct current itself or direct current combined with radio frequency. In order to make this selection, the operator depresses button 450 which controls a mode switch 92. In one position of mode switch 92, the operator has selected direct current (DC) only and in the other position the operator has selected radio frequency (RF) combined with direct current (blend). When blend is selected, the operator can select the RF intensity by adjusting knob 91.
It is to be noted that mounted on the chassis 192 is a needle cord indicator box 468. Mounted within this needle cord indicator box 468 are the light emitting diodes 208, 210, 212, 214, 216 and 218. The number 1 is shown associated with light emitting diode 208, number 2 being associated with light emitting diode 210, number 3 being associated with light emitting diode 212, number 4 being associated with light emitting diode 214, number 5 being associated with light emitting diode 216 and number 6 being associated with light emitting diode 218. Aligning with the number 1 and light emitting diode 208 is probe wire 152. In a similar manner, probe wires 154, 156, 158, 160 and 162 align respectively with light emitting diodes 210, 212, 214, 216 and 218. Each of the probe wires 152, 154, 156, 158, 160 and 162 terminate in a needle (not shown) mounted within a tip 470. It is to be understood that the needle is to be inserted within the follicle of the hair. The probe wires 152, 154, 156, 158, 160 and 162 rest on a roller 480. The roller 480 is mounted on a bracket 562. The bracket 562 is mounted by means of screws 564 and 566 to the chassis 192. The roller 480 provides a low frictional surface for sliding of each of the probe wires 152, 154, 156, 158, 160 and 162 in an inward and outward direction relative to the arm unit 192.
Each of the probe wires 152, 154, 156, 158, 160 and 162 are mounted within a grommet 568 with it being understood that there is a separate grommet 568 for each of the probe wires 152, 154, 156, 158, 160 and 162. It is a function of each grommet 568 to provide a slight frictional resistance to its respective probe wires 152, 154, 156, 158, 160 and 162. The grommets 568 are mounted within a bracket 570 which is fixedly mounted onto the chassis 192. The inner end of each of the probe wires 152, 154, 156, 158, 160 and 162 are mounted by a probe connector 572 to the chassis 192.
It is to be noted that the probe wires 152, 154, 156, 158, 160 and 162 and the tips 470 as well as the needles (not shown) are referred to as probes within this patent application. Mounted within the chassis 192 are a series of ventilation holes 574 through which air is to be conducted in order to dissipate heat from the interior of the chassis 192. The chassis 192 of the arm unit 188 will also include ventilation holes.
Referring specifically to FIG. 5, when the power switch 10 is turned on, alternating (AC) current flows through the connector 12 and through lines 15 and 17 to the power supply 14. Line 15 includes a fuse 29. Chassis ground line 13 also connects between connector 12 and power supply 14. The power supply 14 then supplies -15 volts direct current (VDC) through lines 31, 33 and 35 to fans 20 and 22. Fan 20 is mounted within the chassis of the main unit and functions to dissipate heat produced by the electronics. Fan 22 is mounted in the arm unit. Fan 22 is electrically connected to lines 19 and 21. Lines 19, 21 and 25 are to supply power (±15 volts) and electrical ground to the circuitry wherever this voltage is required. Line 19 is +15 volts, line 25 is -15 volts and line 21 is ground. Lines 19, 21 and 25 are also used to transmit power (±15 volts) to the DC PCB shown in FIGS. 9 and 13. From power supply 14 is a +65 VDC output line 37. Capacitor 516 connects line 37 to RF ground 39, capacitor 516 provides noise bypassing for the +65 VDC. RF ground is shown different than the common analog ground which is not specifically numbered throughout the circuits of the figures.
Plus and minus (±) 15 VDC is supplied to the control PCB shown in FIGS. 7 and 8. Capacitors 28, 30, 32, 34 and 36 provide noise bypassing for the ±15 VDC. Five volt regulator 38 supplies 5 volt DC power to all the integrated circuits of the control PCB of FIGS. 7 and 8 except chips 40, 42, 44 and 236. Diode 46 provides over voltage protection for 5 volt regulator 38. Capacitors 48 and 50 provide noise bypassing for 5 volt regulator 38.
Between the chassis and the control PCB there is mounted resistor 52 which provides signal ground-to-chassis ground isolation shown in FIG. 6. Capacitor 54 provides signal ground noise bypassing between analog ground 53 and chassis ground 56. Mounting screw 58 mounts to chassis 190. Resistor 60 provides a voltage to turn on the light emitting diode (LED) 64 mounted in conjunction with the power switch 10.
The microcontroller integrated circuit 66 controls the total operation of the apparatus of this invention. A desirable microcontroller is Part No. P1C16C5X manufactured by Microchip Technology, Inc. Microcontroller 66 receives and sends data, address (ADO to AD7) and control signals. Microcontroller 66 operates from a 4 megahertz (MHz) resonator 68 which operates between capacitors 16 and 18. Capacitor 70 is a 5 VDC bypass capacitor for microcontroller 66. Five VDC pull up resistor arrays 72 and 74 are operatively connected to microcontroller 66. Chip 76 is a supervisory chip that supervises microcontroller 66 by monitoring the power supply 14 and providing system resets through resistor 78. Capacitor 80 is a 5 VDC bypass capacitor for the supervisory chip 76. Resistor 82 is a 5 VDC pull up resistor and capacitor 84 is a noise bypass capacitor. A reset switch 86 operates through resistor 88 to provide a way to do a master reset of the whole system of this invention putting the system at the start point. Lines 24 and 26, which connect to resistor array 74, connect microcontroller 66 to mode switch 92 which informs microcontroller 66 if the system is in a single or dual current operation mode. The single mode would be DC only and the dual mode would be radio frequency RF and DC. Line 26 supplies a signal received from chip 180.
Chip 94 is an octal D-type flip-flop that receives address signals (ADO-AD7) from microcontroller 66 and sends out data signals (ODO-OD7). A desirable octal D-type flip-flop is manufactured by National Semiconductor, Part No. 54AC/74AC574. The capacitor 96 is a 5 VDC bypass capacitor for chip 94. The control signal from microcontroller 66 is also transmitted through line 90 to chip 94.
Chip 98 is a programmable logic array that receives address signals (ADO-AD7) and control signals from microcontroller 66. The control signal through line 62 includes buffer 100. A desirable logic array would be Part No. 22CV10A, manufactured by ICT, Inc. Chip 98 sends out chip select, latch, control and IO (in/out) write signals in lines 102, 104, 106, 108, 110, 112, 114, 116, 118 and 120. Line 102 connects to chip 312. Line 104 connects to chip 310. Lines 106 and 108 connect to chip 146. Lines 110 and 112 connect to chip 170. Line 114 connects to chip 172. Lines 116 and 118 connect to chip 180. Line 120 connects to chip 232. The capacitor 122 is a 5 VDC bypass capacitor for chip 98.
Chip 124 shown in FIG. 8 is an oscillator/divider that provides a 5 hertz (Hz) frequency operating system. Capacitors 126 and 128, resistor 130 and 6.55 megahertz (MHz) resonator 132 provide an operating frequency for chip 124. Resistors 134, 136 and 138 are 5 VDC pull up resistors. Resistor 140 is a 5 VDC isolation resistor. Capacitor 142 is a 5 VDC bypass capacitor for resistor 140. Capacitor 144 is an isolated 5 VDC bypass capacitor for chip 124.
Chip 146 is a programmable logic array that receives address signals (ADO-AD4) from microcontroller 66 and control signals from programmable logic array 98 through lines 106 and 108. Chip 146 also receives data signals (ODO-OD5) from octal D-type flip flop 94. Chip 146 sends out DC chip select and 10 V reference control signals in lines 152, 154, 156, 158, 160, 162, 164 and 166. Line 152 connects to chip 404 of FIG. 9. Each of the lines 154, 156, 158, 160 and 162 connect respectively in an identical manner to a chip (not shown) that is identical to chip 404. Capacitor 168 is a 5 VDC bypass capacitor for chip 146.
Chip 170 is a programmable logic array that receives address signals (ODO-OD6) from octal D-type flip flop 94, control signals from programmable logic array 98 through lines 110 and 112, and address signals (ADO-AD4) from microcontroller 66. Chip 170 sends out RF disable signals that are buffered by chip 172 which is an octal non-inverting buffer. Capacitor 176 is a 5 VDC bypass capacitor for chip 170. Capacitor 178 is the same for chip 172. The RF disable signal in line 174 from chip 172 is transmitted to feedback amplifier 500 for probe number one. The output signals in lines 171, 173, 175, 177 and 179 are each to be transmitted to a separate RF circuit (not shown) each of which is basically identical to the RF circuit shown in FIG. 10. Chip 172 produces a write signal in line 181 that is transmitted to chip 404 as well as the other not shown five in number of similar circuits. Line 181 is also transmitted to chip 354.
Chip 180 is a programmable logic array that receives data signals (ODO-OD7) from chip 94 as well as the control signals from chips 98 and 100, and a 5 Hz signal in line 183 from chip 124. Capacitor 182 is a 5 VDC bypass capacitor for chip 180. Chip 180 sends out a buffered 5 Hz signal in line 26 and a series of LED signals in lines 186. The LED signals in lines 186 are transmitted to chip 200 which is a 5 volt collector driver. From chip 200 there are six outputs each of which connect to a single LED 208, 210, 212, 214, 216 and 218 which are connected to a 5 VDC pull up resistor array 222. The LED signal in line 224 is transmitted to LED 220. LED 220 indicates to the user that the circuit is either in the cataphoresis mode or the anaphoresis mode. Resistor 230 is a pull up resistor for LED 220.
Chip 232 is an analog-to-digital converter. Chip 232 receives control, clock, 5 volt reference and timer set signals from line 120 of chip 98 and from line 234 from microcontroller 66. Chip 232 sends out a digital voltage to microcontroller 66 in line 228. Capacitors 242 and 244 are 5 VDC bypass capacitors for chip 232. Resistor 246 and capacitor 248 comprise a filtering circuit for the timer pot signal of timer potentiometer 272 in line 250 from chip 232.
Chips 236, 40, 42 and 44 are each operational amplifiers that supply a buffered 0.36 volts, 5 and 10 volt reference voltages. Resistor 238 and diode 240 provide a 5 VDC reference voltage signal to chip 236. Chip 236 provides a 5 VDC buffered reference voltage to chips 40, 42, 44 and through resistor 184 and filtering capacitor 188 to chip 232. Resistor 254 and capacitor 256 comprise a filtering circuit for chip 44. Resistors 258 and 260 in connection with chip 44 provide a buffered 10 VDC reference signal in line 202 through resistor 262 which is supplied to DC potentiometer 342 in FIG. 11. Resistor 262 is a short circuit protection and noise reduction resistor. Resistors 264 and 266 along with transistor 268 are used to turn off the 10 VDC signal. Resistor 264 is mounted in line 166 which is an output of chip 146. Chip 42 provides a buffered 5 volt reference signal that goes through resistor 270 to the timer potentiometer 272. Resistor 270 is a short circuit protection and noise reduction resistor. Resistors 274 and 276 plus chip 40 and the 866 ohm resistor 278 provide a buffered 0.36 volt reference signal that goes through the filtering network of resistor 280 and capacitor 282 to chips 284 and 286. Chips 284 and 286 are quad comparators that receive a 0.36reference voltage and DC analog signals. The DC analog signals are sent through a resistor array divider circuit to chips 284 and 286. The resistor array divider circuit is formed by resistor arrays 290 and 292. Capacitors 294 are bypass capacitors. Chips 284 and 286 send out zero or 5 volt logic signals which are transmitted to 5volt pull up resistor array 308. The outputs from chip 284 coupled with the resistor array 308 are transmitted to chip 310 of an octal inverting buffer. In the same way, the outputs from chip 286 that have been coupled with resistor array 308 are transmitted to chip 312 which is also part of the octal inverting buffer. The octal inverting buffer, composed of chips 310 and 312, receives the logic signals from chips 284 and 286 and sends such to the microcontroller 66. Capacitor 314 is a 5 VDC bypass capacitor for the octal inverting buffer composed of chips 310 and 312.
Referring specifically to FIG. 11, chip 340 comprises a dual operational amplifier that receives DC voltage from the DC set potentiometer 342. Capacitor 344 is a filtering capacitor. Resistors 346, 348 and 350 provide a buffered negative DC voltage. The output of chip 340 in line 330 is transmitted to chip 404 for probe one and also for the identical circuits (not shown) for probes two through six. The output in line 330 is also supplied to chip 354 as well as control signals MDO, MD1 and MD2 from chip 356.
Chip 354 of FIG. 13 is a digital attenuator that receives control signals (MDO, MD1 and MD2) from chip 356. Chip 356 is an octal non-inverting buffer. Part No. 54AC/74AC244, manufactured by National Semiconductor, would be satisfactory. Capacitor 357 is a noise bypassing capacitor for chip 356. Chip 354 sends out a negative DC voltage in line 328 that digitally ramps from 0 to 100 percent in two seconds (20 percent, 50 percent, 80 percent, 100 percent in half-second intervals) to amplifier 360. Capacitor 514 helps slow the ramping and eliminate the sudden heat sensation that is felt by the user. Capacitors 331 and 333 are noise bypassing capacitors for chip 354. Amplifier 360 is one-half of a dual operational amplifier which includes amplifier 362. Amplifier 360 receives a negative DC voltage from chip 354 and buffers it before it is transmitted through resistor 364 to amplifier 362. Amplifier 362, resistor 366, transistors 368 and 370 create a constant direct current source signal that goes to resistor array 290 through line 374 (FIG. 7). Line 374 also connects with a 12 VDC relay 376. Line 374 connects to both lines 380 and 382 which are outputs from the relay 376. Line 380 connects with relay switch 384 with line 382 connecting with relay switch 386. Capacitors 388 and 390 are filtering capacitors. Resistor 392 provides a voltage to the coil 394 of the relay 376. Resistor 396 provides a voltage source to the inductor 398 and capacitor 400 and to switches 384 and 386. Inductor 398 and capacitor 400 are connected to the probe ground line 326 which connects to jack 327 for the probes one through six. Line 380 outputs to jack 381. Line 382 outputs to jack 383. A signal from switch 402 causes the relay 376 to change the position of switches 384 and 386. Switch 402 is to either select cataphoresis or anaphoresis.
Chip 404 is a digital attenuator that receives control signals (MDO, MD1 and MD2) from chip 356 of FIG. 12. Also, a negative DC set voltage is transmitted to chip 404 from line 330 which is the output of chip 340. It is to be understood that the circuits (not shown) for probes two through six, which are essentially identical to FIG. 9, are also to receive control signals MDO, MD1 and MD2 as well as a negative DC set voltage from line 330. Chip 404 sends out a negative DC voltage that digitally ramps from 0-100 percent in two seconds (20 percent, 50 percent, eighty percent in half-second intervals) to chip 406. Capacitors 408 and 410 are noise bypassing capacitors for chip 404. Capacitor 512 helps slow the ramping and eliminate the sudden heat sensation that is felt by the user.
Chip 406 is a dual operational amplifier in conjunction with chip 412. Chip 406 receives a negative DC voltage from chip 404 and buffers this signal through resistor 414 to chip 412. Chip 412, resistor 413 and transistors 416 and 418 create a constant current source signal within line 420 that is transmitted to resistor array 290. The direct current output of chip 412 is also transmitted through resistor 422 in line 421 to the circuit of FIG. 10. Resistor 422 is a short circuit protection and noise reduction resistor. Capacitor 424 is a filtering capacitor. It is to be understood that there are a total of six in number of circuits that are shown in FIG. 9. There is to be a circuit shown in FIG. 9 for each probe one through six. The output in line 420 is transmitted to the circuit for probe one (FIG. 9). The output of a similar circuit is transmitted to the circuit by probe two similar to FIG. 10 and so forth up to probe six. The output signals of each of these circuits of probe two through six are transmitted respectively through lines 430, 432, 434, 436 and 438 to resistor array 290.
Plus and minus 15 volts DC from lines 31, 33 and 35 and +65 VDC from line 37 are supplied to the RF circuit shown in FIG. 10. Chip 456 in FIG. 11 is a dual operational amplifier that receives a DC voltage from the DC set potentiometer 342 through resistor 458. Capacitor 460 is a filter capacitor. Chip 456 sends out a buffered DC voltage through line 452 to the DC meter 462 through the trim potentiometer 464 and resistor 466.
Chip 558 is a dual operational amplifier. One half of chip 558 is a buffer for the DC voltage from the divider circuit of resistors 551 and 553 and trim potentiometer 552. Trim potentiometer 552 is used to set the high end (40 VP-P) of the RF output. The other half of chip 556 is a buffer for the DC voltage from the divider circuit of resistors 554 and 557 and trim potentiometer 556. Trim potentiometer 556 is used to set the low end (30 VP-P) of the RF output. Resistors 478 and 480 provide noise reduction to the RF potentiometer 484. The RF potentiometer 484 is used to adjust the RF output at the patient from 30 VP-P to 40VP-P.
Chip 472 in FIG. 14 is a wideband, variable gain amplifier that receives a frequency from the 13.56 MHz crystal 474 and resistor 476. A typical wideband, variable gain amplifier would be part no. EL4551C manufactured by ELANTEC. Capacitors 468 and 470 are bypass capacitors. Resistors 490 and 492, diode 494 and capacitor 496 form a feedback circuit to chip 472 for balancing the RF output signal. The RF output signal goes to two separate resistor divider circuits. The signal from RF potentiometer 484 goes through the noise filtering circuit of resistor 482 and capacitor 518.
The RF output from chip 472 goes to two gain circuits. Resistors 498 and 528 form one RF gain circuit. Resistors 522 and 524 form the other gain circuit. Capacitor 526 is an AC coupling capacitor that goes to probes 1, 2 and 3. Capacitor 522 is an AC coupling capacitor that goes to the probes 4, 5 and 6.
Chip 500 is connected to probe number 1. Separate circuits similar to FIG. 10A will be used for probe number 2 and probe number 3. Chip 500 is 110 MHz current feedback amplifier with disable that receives an RF disable signal in line 174. Part No. EL2155C of ELANTEC is a satisfactory part for this purpose. Chip 500 also receives the output signal of line 506 from capacitor 526. It is to be understood that each of the circuits similar to FIG. 10A for probes two and three will also receive the signal of line 506. Resistors 508 and 510 cause chip 500 to amplify the radio frequency signal by a factor of two. Capacitor 520 is an AC coupling capacitor.
Chip 538 is a triple 80 MHz CRT driver that receives the amplified RF signal from capacitor 520 through the gain resistor 521. For chip 538 part No. LM2427T manufactured by National Semiconductor would be a satisfactory part for this purpose. Chip 538 is also grounded by RF ground 539. Probe 1 is also grounded by RF ground 541. Resistor 531 cause chip 538 to amplify the RF signal by a factor of -13. The output of chip 538 goes through the impedance resistor 532. Capacitor 540 is an AC coupling capacitor that allows the RF current source signal from resistor 532 to be transmitted to probe 1. It is to be kept in mind that there are six in number of different probes. The constant DC source signal in line 544 is conducted through the AC filtering circuit composed of inductor 546 and capacitors 548 and 550 to probe 1.
Referring now to Figure 10B, there is shown a circuit for probe 4 with similar separate circuits to be used for probes 5 and 6. Chip 562 is connected to probe number 4. Chip 562 is a 110 MHz current feedback amplifier with disable that receives an RF disable signal from line 175. Chip 562 also receives the output signal of line 533 from capacitor 530. It is to be understood that each of the circuits similar to Figure 10B for probes 5 and 6 will also receive the signal of line 533. Resistors 560 and 561 cause chip 562 to amplify the radio frequency signal by a factor of two. Capacitor 563 is an AC coupling capacitor.
Chip 565 is a triple 80 MHz CRT driver that receives the amplified RF signal from capacitor 563 through the gain resistor 564. Resistor 564 causes chip 565 to amplify the RF signal by a factor of -13. Chip 565 is also grounded by RF ground 572. Probe 4 is also grounded by RF ground 573. The output of chip 565 goes through the impedance resistor 566. Capacitor 567 is an AC coupling capacitor that allows the RF current source signal from resistor 566 to be transmitted to probe 4. The constant DC source signal in line 544 is conducted through the AC filtering circuit composed of inductor 569 and capacitors 570 and 571 to probe 4.
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An electrolysis machine which uses a plurality of probes each of which is to be insertable in conjunction with a hair follicle to effect removing of a hair. The probes are mounted on an arm unit which is adjustably movable to a multitude of different positions relative to a base unit which is fixedly located on a supporting surface. An electrolysis machine produces both direct current and a radio frequency with the user being able to select just the direct current or the direct current combined with the radio frequency in the performing of the destruction of the hair. The current emitted to effect the destruction of the hair is slowly raised (over a two second time period) to a level that is preset by the operator.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 10/263,329, filed Oct. 2, 2002.
TECHNICAL FIELD
This invention concerns selective destruction of rapidly dividing cells, and more particularly, to an apparatus for selectively destroying dividing cells by applying an electric field having certain prescribed characteristics.
BACKGROUND
All living organisms proliferate by cell division, including cell cultures, microorganisms (such as bacteria, mycoplasma, yeast, protozoa, and other single-celled organisms), fungi, algae, plant cells, etc. Dividing cells of organisms can be destroyed, or their proliferation controlled, by methods that are based on the sensitivity of the dividing cells of these organisms to certain agents. For example, certain antibiotics stop the multiplication process of bacteria.
The process of eukaryotic cell division is called “mitosis”, which involves nice distinct phases (see Darnell et al., Molecular Cell Biology, New York: Scientific American Books, 1986, p. 149). During interphase, the cell replicates chromosomal DNA, which begins condensing in early prophase. At this point, centrioles (each cell contains 2) begin moving towards opposite poles of the cell. In middle prophase, each chromosome is composed of duplicate chromatids. Microtubular spindles radiate from regions adjacent to the centrioles, which are closer to their poles. By late prophase, the centrioles have reached the poles, and some spindle fibers extend to the center of the cell, while others extend from the poles to the chromatids. The cells then move into metaphase, when the chromosomes move toward the equator of the cell and align in the equatorial plane. Next is early anaphase, during which time daughter chromatids separate from each other at the equator by moving along the spindle fibers toward a centromere at opposite poles. The cell begins to elongate along the axis of the pole; the pole-to-pole spindles also elongate. Late anaphase occurs when the daughter chromosomes (as they are not called) each reach their respective opposite poles. At this point, cytokinesis begins as the cleavage furrow begins to form at the equator of the cell. In other words, late anaphase is the point at which pinching the cell membrane begins. During telophase, cytokinesis is nearly complete and spindles disappear. Only a relatively narrow membrane connection joins the two cytoplasms. Finally, the membranes separate fully, cytokinesis is complete and the cell returns to interphase.
In meiosis, the cell undergoes a second division, involving separation of sister chromosomes to opposite poles of the cell along spindle fibers, followed by formation of a cleavage furrow and cell division. However, this division is not preceded by chromosome replication, yielding a haploid germ cell.
Bacteria also divide by chromosome replication, followed by cell separation. However, since the daughter chromosomes separate by attachment to membrane components; there is no visible apparatus that contributes to cell division as in eukaryotic cells.
It is well known that tumors, particularly malignant or cancerous tumors, grow uncontrollably compared to normal tissue. Such expedited growth enables tumors to occupy an ever-increasing space and to damage or destroy tissue adjacent thereto. Furthermore, certain cancers are characterized by an ability to transmit cancerous “seeds”, including single cells or small cell clusters (metastases), to new locations where the metastatic cancer cells grow into additional tumors.
The rapid growth of tumors, in general, and malignant tumors in particular, as described above, is the result of relatively frequent cell division or multiplication of these cells compared to normal tissue cells. The distinguishably frequent cell division of cancer cells is the basis for the effectiveness of existing cancer treatments, e.g., irradiation therapy and the use of various chemo-therapeutic agents. Such treatments are based on the fact that cells undergoing division are more sensitive to radiation and chemo-therapeutic agents than non-dividing cells. Because tumors cells divide much more frequently than normal cells, it is possible, to a certain extent, to selectively damage or destroy tumor cells by radiation therapy and/or chemotherapy. The actual sensitivity of cells to radiation, therapeutic agents, etc., is also dependent on specific characteristics of different types of normal or malignant cell types. Thus, unfortunately, the sensitivity of tumor cells is not sufficiently higher than that many types of normal tissues. This diminishes the ability to distinguish between tumor cells and normal cells, and therefore, existing cancer treatments typically cause significant damage to normal tissues, thus limiting the therapeutic effectiveness of such treatments. Furthermore, the inevitable damage to other tissue renders treatments very traumatic to the patients and, often, patients are unable to recover from a seemingly successful treatment. Also, certain types of tumors are not sensitive at all to existing methods of treatment.
There are also other methods for destroying cells that do not rely on radiation therapy or chemotherapy alone. For example, ultrasonic and electrical methods for destroying tumor cells can be used in addition to or instead of conventional treatments. Electric fields and currents have been used for medical purposes for many years. The most common is the generation of electric currents in a human or animal body by application of an electric field by means of a pair of conductive electrodes between which a potential difference is maintained. These electric currents are used either to exert their specific effects, i.e., to stimulate excitable tissue, or to generate heat by flowing in the body since it acts as a resistor. Examples of the first type of application include the following: cardiac defibrillators, peripheral nerve and muscle stimulators, brain stimulators, etc. Currents are used for heating, for example, in devices for tumor ablation, ablation of malfunctioning cardiac or brain tissue, cauterization, relaxation of muscle rheumatic pain and other pain, etc.
Another use of electric fields for medical purposes involves the utilization of high frequency oscillating fields transmitted from a source that emits an electric wave, such as an RF wave or a microwave source that is directed at the part of the body that is of interest (i.e., target). In these instances, there is no electric energy conduction between the source and the body; but rather, the energy is transmitted to the body by radiation or induction. More specifically, the electric energy generated by the source reaches the vicinity of the body via a conductor and is transmitted from it through air or some other electric insulating material to the human body.
In a conventional electrical method, electrical current is delivered to a region of the target tissue using electrodes that are placed in contact with the body of the patient. The applied electrical current destroys substantially all cells in the vicinity of the target tissue. Thus, this type of electrical method does not discriminate between different types of cells within the target tissue and results in the destruction of both tumor cells and normal cells.
Electric fields that can be used in medical applications can thus be separated generally into two different modes. In the first mode, the electric fields are applied to the body or tissues by means of conducting electrodes. These electric fields can be separated into two types, namely (1) steady fields or fields that change at relatively slow rates, and alternating fields of low frequencies that induce corresponding electric currents in the body or tissues, and (2) high frequency alternating fields (above 1 MHz) applied to the body by means of the conducting electrodes. In the second mode, the electric fields are high frequency alternating fields applied to the body by means of insulated electrodes.
The first type of electric field is used, for example, to stimulate nerves and muscles, pace the heart, etc. In fact, such fields are used in nature to propagate signals in nerve and muscle fibers, central nervous system (CNS), heart, etc. The recording of such natural fields is the basis for the ECG, EEG, EMG, ERG, etc. The field strength in these applications, assuming a medium of homogenous electric properties, is simply the voltage applied to the stimulating/recording electrodes divided by the distance between them. These currents can be calculated by Ohm's law and can have dangerous stimulatory effects on the heart and CNS and can result in potentially harmful ion concentration changes. Also, if the currents are strong enough, they can cause excessive heating in the tissues. This heating can be calculated by the power dissipated in the tissue (the product of the voltage and the current).
When such electric fields and currents are alternating, their stimulatory power, on nerve, muscle, etc., is an inverse function of the frequency. At frequencies above 1-10 kHz, the stimulation power of the fields approaches zero. This limitation is due to the fact that excitation induced by electric stimulation is normally mediated by membrane potential changes, the rate of which is limited by the RC properties (time constants on the order of 1 ms) of the membrane.
Regardless of the frequency, when such current inducing fields are applied, they are associated with harmful side effects caused by currents. For example, one negative effect is the changes in ionic concentration in the various “compartments” within the system, and the harmful products of the electrolysis taking place at the electrodes, or the medium in which the tissues are imbedded. The changes in ion concentrations occur whenever the system includes two or more compartments between which the organism maintains ion concentration differences. For example, for most tissues, [Ca ++ ] in the extracellular fluid is about 2×10 −3 M, while in the cytoplasm of typical cells its concentration can be as low as 10 −7 M. A current induced in such a system by a pair of electrodes, flows in part from the extracellular fluid into the cells and out again into the extracellular medium. About 2% of the current flowing into the cells is carried by the Ca ++ ions. In contrast, because the concentration of intracellular Ca ++ is much smaller, only a negligible fraction of the currents that exits the cells is carried by these ions. Thus, Ca ++ ions accumulate in the cells such that their concentrations in the cells increases, while the concentration in the extracellular compartment may decrease. These effects are observed for both DC and alternating currents (AC). The rate of accumulation of the ions depends on the current intensity ion mobilities, membrane ion conductance, etc. An increase in [Ca ++ ] is harmful to most cells and if sufficiently high will lead to the destruction of the cells. Similar considerations apply to other ions. In view of the above observations, long term current application to living organisms or tissues can result in significant damage. Another major problem that is associated with such electric fields, is due to the electrolysis process that takes place at the electrode surfaces. Here charges are transferred between the metal (electrons) and the electrolytic solution (ions) such that charged active radicals are formed. These can cause significant damage to organic molecules, especially macromolecules and thus damage the living cells and tissues.
In contrast, when high frequency electric fields, above 1 MHz and usually in practice in the range of GHz, are induced in tissues usually by means of insulated electrodes or transmission of EM waves, the situation is quite different. These type of fields generate only capacitive or displacement currents, rather than the conventional charge conducting currents. Under the effect of this type of field, living tissues behave mostly according to their dielectric properties rather than their electric conductive properties. Therefore, the dominant field effect is that due to dielectric losses and heating. Thus, it is widely accepted that in practice, the meaningful effects of such fields on living organisms, are only those due to their heating effects, i.e., due to dielectric losses.
In U.S. Pat. No. 6,043,066 ('066) to Mangano, a method and device are presented which enable discrete objects having a conducting inner core, surrounded by a dielectric membrane to be selectively inactivated by electric fields via irreversible breakdown of their dielectric membrane. One potential application for this is in the selection and purging of certain biological cells in a suspension. According to the '066 patent, an electric field is applied for targeting selected cells to cause breakdown of the dielectric membranes of these tumor cells, while purportedly not adversely affecting other desired subpopulations of cells. The cells are selected on the basis of intrinsic or induced differences in a characteristic electroporation threshold. The differences in this threshold can depend upon a number of parameters, including the difference in cell size.
The method of the '066 patent is therefore based on the assumption that the electroporation threshold of tumor cells is sufficiently distinguishable from that of normal cells because of differences in cell size and differences in the dielectric properties of the cell membranes. Based upon this assumption, the larger size of many types of tumor cells makes these cells more susceptible to electroporation and thus, it may be possible to selectively damage only the larger tumor cell membranes by applying an appropriate electric field. One disadvantage of this method is that the ability to discriminate is highly dependent upon cell type, for example, the size difference between normal cells and tumor cells is significant only in certain types of cells. Another drawback of this method is that the voltages which are applied can damage some of the normal cells and may not damage all of the tumor cells because the differences in size and membrane dielectric properties are largely statistical and the actual cell geometries and dielectric properties can vary significantly.
What is needed in the art and has heretofore not been available is an apparatus for killing dividing cells, wherein the apparatus better discriminates between dividing cells, including single-celled organisms, and non-dividing cells and is capable of selectively destroying the dividing cells or organisms with substantially no affect on the non-dividing cells or organisms.
SUMMARY
An apparatus for use in a number of different applications for selectively destroying cells undergoing growth and division is provided. This includes, cell, particularly tumor cells, in living tissue and single-celled organisms. The apparatus can be incorporated into a number of different configurations (e.g., as a skin patch or embedded internally within the body) to eliminate or control the growth of such living tissue or organisms.
A major use of the present apparatus is in the treatment of tumors by selective destruction of tumor cells with substantially no affect on normal tissue cells, and thus, the exemplary apparatus is described below in the context of selective destruction of tumor cells. It should be appreciated however, that for purpose of the following description, the term “cell” may also refer to a single-celled organism (eubacteria, bacteria, yeast, protozoa), multi-celled organisms (fungi, algae, mold), and plants as or parts thereof that are not normally classified as “cells”. The exemplary apparatus enables selective destruction of cells undergoing division in a way that is more effective and more accurate (e.g., more adaptable to be aimed at specific targets) than existing methods. Further, the present apparatus causes minimal damage, if any, to normal tissue and, thus, reduces or eliminates many side-effects associated with existing selective destruction methods, such as radiation therapy and chemotherapy. The selective destruction of dividing cells using the present apparatus does not depend on the sensitivity of the cells to chemical agents or radiation. Instead, the selective destruction of dividing cells is based on distinguishable geometrical and structural characteristics of cells undergoing division, in comparison to non-dividing cells, regardless of the cell geometry of the type of cells being treated.
According to one exemplary embodiment, cell geometry-dependent selective destruction of living tissue is performed by inducing a non-homogenous electric field in the cells using an electronic apparatus.
It has been observed by the present inventor that, while different cells in their non-dividing state may have different shapes, e.g., spherical, ellipsoidal, cylindrical, “pancake-like”, etc., the division process of practically all cells is characterized by development of a “cleavage furrow” in late anaphase and telophase. This cleavage furrow is a slow constriction of the cell membrane (between the two sets of daughter chromosomes) which appears microscopically as a growing cleft (e.g., a groove or notch) that gradually separates the cell into two new cells. During the division process, there is a transient period (telophase) during which the cell structure is basically that of two sub-cells interconnected by a narrow “bridge” formed of the cell material. The division process is completed when the “bridge” between the two sub-cells is broken. The selective destruction of tumor cells using the present electronic apparatus utilizes this unique geometrical feature of dividing cells.
When a cell or a group of cells are under natural conditions or environment, i.e., part of a living tissue, they are disposed surrounded by a conductive environment consisting mostly of an electrolytic inter-cellular fluid and other cells that are composed mostly of an electrolytic intra-cellular liquid. When an electric field is induced in the living tissue, by applying an electric potential across the tissue, an electric field is formed in the tissue and the specific distribution and configuration of the electric field lines defines the paths of electric currents in the tissue, if currents are in fact induced in the tissue. The distribution and configuration of the electric field is dependent on various parameters of the tissue, including the geometry and the electric properties of the different tissue components, and the relative conductivities, capacities and dielectric constants (that may be frequency dependent) of the tissue components.
The electric current flow pattern for cells undergoing division is very different and unique as compared to non-dividing cells. Such cells including first and second sub-cells, namely an “original” cell and a newly formed cell, that are connected by a cytoplasm “bridge” or “neck”. The currents penetrate the first sub-cell through part of the membrane (“the current source pole”); however, they do not exit the first sub-cell through a portion of its membrane closer to the opposite pole (“the current sink pole”). Instead, the lines of current flow converge at the neck or cytoplasm bridge, whereby the density of the current flow lines is greatly increased. A corresponding, “mirror image”, process that takes place in the second sub-cell, whereby the current flow lines diverge to a lower density configuration as they depart from the bridge, and finally exit the second sub-cell from a part of its membrane closes to the current sink.
When a polar or a polarizable object is placed in a non-uniform converging or diverging field, electric forces act on it and pull it towards the higher density electric field lines. In the case of dividing cell, electric forces are exerted in the direction of the cytoplasm bridge between the two cells. Since all intercellular organelles are polarizable, and most macromolecules are polar (have a dipole moment) they are all force towards the bridge between the two cells. The field polarity is irrelevant to the direction of the force and, therefore, an alternating electric having specific properties can be used to produce substantially the same effect. It will also be appreciated that the concentrated electric field present in or near the bridge or neck portion in itself exerts strong forces on charges and natural dipoles and can lead to the disruption of structures associated with these members.
The movement of the cellular organelles towards the bridge disrupts the cell structure and results in increased pressure in the vicinity of the connecting bridge membrane. This pressure of the organelles on the bridge membrane is expected to break the bridge membrane and, thus, it is expected that the dividing cell will “explode” in response to this pressure. The ability to break the membrane and disrupt other cell structures can be enhanced by applying a pulsating alternating electric field that has a frequency from about 50 kHz to about 500 kHz. When this type of electric field is applied to the tissue, the forces exerted on the intercellular organelles have a “hammering” effect, whereby force pulses (or beats) are applied to the organelles numerous times per second, enhancing the movement of organelles of different sizes and masses towards the bridge (or neck) portion from both of the sub-cells, thereby increasing the probability of breaking the cell membrane at the bridge portion. The forces exerted on the intracellular organelles also affect the organelles themselves and may collapse or break the organelles.
According to one exemplary embodiment, the apparatus for applying the electric field is an electronic apparatus that generates the desired electric signals in the shape of waveforms or trains of pulses. The electronic apparatus includes a generator that generates an alternating voltage waveform at frequencies in the range from about 50 kHz to about 500 kHz. The generator is operatively connected to conductive leads which are connected at their other ends to insulated conductors/electrodes (also referred to as isolects) that are activated by the generated waveforms. The insulated electrodes consist of a conductor in contact with a dielectric (insulating layer) that is in contact with the conductive tissue, thus forming a capacitor. The electric fields that are generated by the present apparatus can be applied in several different modes depending upon the precise treatment application.
In one exemplary embodiment, the electric fields are applied by external insulated electrodes which are constructed so that the applied electric fields can be of a local type or of a widely distributed type. This embodiment is designed to treat skin tumors and lesions that are close to the skin surface. According to this embodiment, the insulated electrodes can be incorporated into a skin patch that is applied to a skin surface. The skin patch can be a self-adhesive flexible patch and can include one or more pairs of the insulated electrodes.
According to another embodiment, the apparatus is used in an internal type application in that the insulated electrodes are in the form of plates, wires, etc., that are inserted subcutaneously or deeper within the body so as to generate an electric field having the above desired properties at a target area (e.g., a tumor).
Thus, the present apparatus utilizes electric fields that fall into a special intermediate category relative to previous high and low frequency applications in that the present electric fields are bio-effective fields that have no meaningful stimulatory effects and no thermal effects. Advantageously, when non-dividing cells are subjected to these electric fields, there is no effect on the cells; however, the situation is much different when dividing cells are subjected to the present electric fields. Thus, the present electronic apparatus and the generated electric fields target dividing cells, such as tumors or the like, and do not target non-dividing cells that is found around in healthy tissue surrounding the target area. Furthermore, since the present apparatus utilizes insulated electrodes, the above mentioned negative effects, obtained when conductive electrodes are used, i.e., ion concentration changes in the cells and the formation of harmful agents by electrolysis, do not occur with the present apparatus. This is because, in general, no actual transfer of charges takes place between the electrodes and the medium, and there is no charge flow in the medium where the currents are capacitive.
It should be appreciated that the present electronic apparatus can also be used in applications other than treatment of tumors in the living body. In fact, the selective destruction utilizing the present apparatus can be used in conjunction with any organism that proliferates division and multiplication, for example, tissue cultures, microorganisms, such as bacteria, mycoplasma, protozoa, fungi, algae, plant cells, etc. Such organisms divide by the formation of a groove or cleft as described above. As the groove or cleft deepens, a narrow bridge is formed between the two parts of the organism, similar to the bridge formed between the sub-cells of dividing animal cells. Since such organisms are covered by a membrane having a relatively low electric conductivity, similar to an animal cell membrane described above, the electric field lines in a dividing organism converge at the bridge connecting the two parts of the dividing organism. The converging field lines result in electric forces that displace polarizable elements within the dividing organism.
The above, and other objects, features and advantages of the present apparatus will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIGS. 1A-1E are simplified, schematic, cross-sectional, illustrations of various stages of a cell division process;
FIGS. 2A and 2B are schematic illustrations of a non-dividing cell being subjected to an electric field;
FIGS. 3A , 3 B and 3 C are schematic illustrations of a dividing cell being subjected to an electric field according to one exemplary embodiment, resulting in destruction of the cell ( FIG. 3C ) in accordance with one exemplary embodiment;
FIG. 4 is a schematic illustration of a dividing cell at one stage being subject to an electric field;
FIG. 5 is a schematic diagram of an apparatus for applying an electric according to one exemplary embodiment for selectively destroying cells;
FIG. 6 is a simplified schematic diagram of an equivalent electric circuit of insulated electrodes of the apparatus of FIG. 5 ;
FIG. 7 is a schematic illustration of a skin patch incorporating the apparatus of FIG. 5 and for placement on a skin surface for treating a tumor or the like;
FIG. 8 is a schematic illustration of the insulated electrodes implanted within the body for treating a tumor or the like;
FIG. 9 is a schematic illustration of the insulated electrodes implanted within the body for treating a tumor or the like;
FIGS. 10A-10D are schematic illustrations of various constructions of the insulated electrodes of the apparatus of FIG. 5 ;
FIG. 11 is a schematic illustration of two insulated electrodes being arranged about a human torso for treatment of a tumor container within the body, e.g., a tumor associated with lung cancer;
FIGS. 12A-12C are schematic illustrations of various insulated electrodes with and without protective members formed as a part of the construction thereof; and
FIG. 13 is a schematic illustration of insulated electrodes that are arranged for focusing the electric field at a desired target while leaving other areas in low field density (i.e., protected areas).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is made to FIGS. 1A-1E which schematically illustrate various stages of a cell division process. FIG. 1A illustrates a cell 10 at its normal geometry, which can be generally spherical (as illustrated in the drawings), ellipsoidal, cylindrical, “pancake-like” or any other cell geometry, as is known in the art. FIGS. 1B-1D illustrate cell 10 during different stages of its division process, which results in the formation of two new cells 18 and 20 , shown in FIG. 1E .
As shown in FIGS. 1B-1D , the division process of cell 10 is characterized by a slowly growing cleft 12 which gradually separates cell 10 into two units, namely sub-cells 14 and 16 , which eventually evolve into new cells 18 and 20 ( FIG. 1E ). A shown specifically in FIG. 1D , the division process is characterized by a transient period during which the structure of cell 10 is basically that of the two sub-cells 14 and 16 interconnected by a narrow “bridge” 22 containing cell material (cytoplasm surrounded by cell membrane).
Reference is now made to FIGS. 2A and 2B , which schematically illustrate non-dividing cell 10 being subjected to an electric field produced by applying an alternating electric potential, at a relatively low frequency and at a relatively high frequency, respectively. Cell 10 includes intracellular organelles, e.g., a nucleus 30 . Alternating electric potential is applied across electrodes 28 and 32 that can be attached externally to a patient at a predetermined region, e.g., in the vicinity of the tumor being treated. When cell 10 is under natural conditions, i.e., part of a living tissue, it is disposed in a conductive environment (hereinafter referred to as a “volume conductor”) consisting mostly of electrolytic inter-cellular liquid. When an electric potential is applied across electrodes 28 and 32 , some of the field lines of the resultant electric field (or the current induced in the tissue in response to the electric field) penetrate the cell 10 , while the rest of the field lines (or induced current) flow in the surrounding medium. The specific distribution of the electric field lines, which is substantially consistent with the direction of current flow in this instance, depends on the geometry and the electric properties of the system components, e.g., the relative conductivities and dielectric constants of the system components, that can be frequency dependent. For low frequencies, e.g., frequencies lower than 10 kHz, the conductance properties of the components completely dominate the current flow and the field distribution, and the field distribution is generally as depicted in FIG. 2A . At higher frequencies, e.g., at frequencies of between 10 kHz and 1 MHz, the dielectric properties of the components becomes more significant and eventually dominate the field distribution, resulting in field distribution lines as depicted generally in FIG. 2B .
For constant (i.e., DC) electric fields or relatively low frequency alternating electric fields, for example, frequencies under 10 kHz, the dielectric properties of the various components are not significant in determining and computing the field distribution. Therefore, as a first approximation, with regard to the electric field distribution, the system can be reasonably represented by the relative impedances of its various components. Using this approximation, the intercellular (i.e., extracellular) fluid and the intracellular fluid each has a relatively low impedance, while the cell membrane 11 has a relatively high impedance. Thus, under low frequency conditions, only a fraction of the electric field lines (or currents induced by the electric field) penetrate membrane 11 of the cell 10 . At relatively high frequencies (e.g., 10 kHz-1 MHz), in contrast, the impedance of membrane 11 relative to the intercellular and intracellular fluids decreases, and thus, the fraction of currents penetrating the cells increases significantly. It should be noted that at very high frequencies, i.e., above 1 MHz, the membrane capacitance can short the membrane resistance and, therefore, the total membrane resistance can become negligible.
In any of the embodiments described above, the electric field lines (or induced currents) penetrate cell 10 from a portion of the membrane 11 closest to one of the electrodes generating the current, e.g., closest to positive electrode 28 (also referred to herein as “source”). The current flow pattern across cell 10 is generally uniform because, under the above approximation, the field induced inside the cell is substantially homogeneous. The currents exit cell 10 through a portion of membrane 11 closest to the opposite electrode, e.g., negative electrode 32 (also referred to herein as “sink”).
The distinction between field lines and current flow can depend on a number of factors, for example, on the frequency of the applied electric potential and on whether electrodes 28 and 32 are electrically insulated. For insulated electrodes applying a DC or low frequency alternating voltage, there is practically no current flow along the lines of the electric field. At higher frequencies, the displacement currents are induced in the tissue due to charging and discharging of the electrode insulation and the cell membranes (which act as capacitors to a certain extent), and such currents follow the lines of the electric field. Fields generated by non-insulated electrodes, in contrast, always generate some form of current flow, specifically, DC or low frequency alternating fields generate conductive current flow along the field lines, and high frequency alternating fields generate both conduction and displacement currents along the field lines. It should be appreciated, however, that movement of polarizable intracellular organelles according to the present invention (as described below) is not dependent on actual flow of current and, therefore, both insulated and non-insulated electrodes can be used efficiently. Several advantages of insulated electrodes are that they have lower power consumption and cause less heating of the treated regions.
According to one exemplary embodiment of the present invention, the electric fields that are used are alternating fields having frequencies that are in the range from about 50 kHz to about 500 kHz, and preferably from about 100 kHz to about 300 kHz. For ease of discussion, these type of electric fields are also referred to below as “TC fields”, which is an abbreviation of “Tumor Curing electric fields”, since these electric fields fall into an intermediate category (between high and low frequency ranges) that have bio-effective field properties while having no meaningful stimulatory and thermal effects. These frequencies are sufficiently low so that the system behavior is determined by the system's Ohmic (conductive) properties but sufficiently high enough not to have any stimulation effect on excitable tissues. Such a system consists of two types of elements, namely, the intercellular, or extracellular fluid, or medium and the individual cells. The intercellular fluid is mostly an electrolyte with a specific resistance of about 40-100 Ohm*cm. As mentioned above, the cells are characterized by three elements, namely (1) a thin, highly electric resistive membrane that coats the cell; (2) internal cytoplasm that is mostly an electrolyte that contains numerous macromolecules and micro-organelles, including the nucleus; and (3) membranes, similar in their electric properties to the cell membrane, cover the micro-organelles.
When this type of system is subjected to the present TC fields (e.g., alternating electric fields in the frequency range of 100 kHz-300 kHz) most of the lines of the electric field and currents tend away from the cells because of the high resistive cell membrane and therefore the lines remain in the extracellular conductive medium. In the above recited frequency range, the actual fraction of electric field or currents that penetrates the cells is a strong function of the frequency.
FIG. 3 schematically depicts the resulting field distribution in the system. As illustrated, the lines of force, which also depict the lines of potential current flow across the cell volume mostly in parallel with the undistorted lines of force (the main direction of the electric field). In other words, the field inside the cells is mostly homogeneous. In practice, the fraction of the field or current that penetrates the cells is determined by the cell membrane impedance value relative to that of the extracellular fluid. Since the equivalent electric circuit of the cell membrane is that of a resistor and capacitor in parallel, the impedance is a function of the frequency. The higher the frequency, the lower the impedance, the larger the fraction of penetrating current and the smaller the field distortion.
As previously mentioned, when cells are subjected to relatively weak electric fields and currents that alternate at high frequencies, such as the present TC fields having a frequency in the range of 50 kHz-500 kHz, they have no effect on the non-dividing cells. While the present TC fields have no detectable effect on such systems, the situation becomes different in the presence of dividing cells.
Reference is now made to FIGS. 3A-3C which schematically illustrate the electric current flow pattern in cell 10 during its division process, under the influence of alternating fields (TC fields) in the frequency range from about 100 kHz to about 300 kHz in accordance with one exemplary embodiment. The field lines or induced currents penetrate cell 10 through a part of the membrane of sub-cell 16 closer to electrode 28 . However, they do not exit through the cytoplasm bridge 22 that connects sub-cell 16 with the newly formed yet still attached sub-cell 14 , or through a part of the membrane in the vicinity of the bridge 22 . Instead, the electric field or current flow lines—that are relatively widely separated in sub-cell 16 —converge as they approach bridge 22 (also referred to as “neck” 22 ) and, thus, the current/field line density within neck 22 is increased dramatically. A “mirror image” process takes place in sub-cell 14 , whereby the converging field lines in bridge 22 diverge as they approach the exit region of sub-cell 14 .
It should be appreciated by persons skilled in the art that homogeneous electric fields do not exert a force on electrically neutral objects, i.e., objects having substantially zero net charge, although such objects can become polarized. However, under a non-uniform, converging electric field, as shown in FIGS. 3A-3C , electric forces are exerted on polarized objects, moving them in the direction of the higher density electric field lines. It will be appreciated that the concentrated electric field that is present in the neck or bridge area in itself exerts strong forces on charges and natural dipoles and can disrupt structures that are associated therewith.
In the configuration of FIGS. 3A and 3B , the direction of movement of polarized objects is towards the higher density electric field lines, i.e., towards the cytoplasm bridge 22 between sub-cells 14 and 16 . It is known in the art that all intracellular organelles, for example, nuclei 24 and 26 of sub-cells 14 and 16 , respectively, are polarizable and, thus, such intracellular organelles are electrically forced in the direction of the bridge 22 . Since the movement is always from lower density currents to the higher density currents, regardless of the field polarity, the forces applied by the alternating electric field to organelles, such as nuclei 24 and 26 , are always in the direction of bridge 22 . A comprehensive description of such forces and the resulting movement of macromolecules of intracellular organelles, a phenomenon referred to as “dielectrophoresis” is described extensively in literature, e.g., in C. L. Asbury & G. van den Engh, Biophys. J. 74, 1024-1030, 1998, the disclosure of which is hereby incorporated by reference in its entirety.
The movement of the organelles 24 and 26 towards the bridge 22 disrupts the structure of the dividing cell and, eventually, the pressure of the converging organelles on bridge membrane 22 results in the breakage of cell membrane 11 at the vicinity of the bridge 22 , as shown schematically in FIG. 3C . The ability to break membrane 11 at bridge 22 and to otherwise disrupt the cell structure and organization can be enhanced by applying a pulsating AC electric field, rather than a steady AC field. When a pulsating field is applied, the forces acting on organelles 24 and 26 have a “hammering” effect, whereby pulsed forces beat on the intracellular organelles towards the neck 22 from both sub-cells 14 and 16 , thereby increasing the probability of breaking cell membrane 11 in the vicinity of neck 22 .
A very important element, which is very susceptible to the special fields that develop within the dividing cells is the microtubule spindle that plays a major role in the division process. In FIG. 4 , a dividing cell 10 is illustrated, at an earlier stage as compared to FIGS. 3A and 3B , under the influence of external TC fields (e.g., alternating fields in the frequency range of about 100 kHz to about 300 kHz), generally indicated as lines 100 , with a corresponding spindle mechanism generally indicated at 120 . The lines 120 are microtubules that are known to have a very strong dipole moment. This strong polarization makes the tubules susceptible to electric fields. Their positive charges are located at the two centrioles while two sets of negative poles are at the center of the dividing cell and the other pair is at the points of attachment of the microtubules to the cell membrane, generally indicated at 130 . This structure forms sets of double dipoles and therefore they are susceptible to fields of different directions. It will be understood that the effect of the TC fields on the dipoles does not depend on the formation of the bridge (neck) and thus, the dipoles are influenced by the TC fields prior to the formation of the bridge (neck).
Since the present apparatus (as will be described in greater detail below) utilizes insulated electrodes, the above-mentioned negative effects obtained when conductive electrodes are used, i.e., ion concentration changes in the cells and the formation of harmful agents by electrolysis, do not occur when the present apparatus is used. This is because, in general, no actual transfer of charges takes place between the electrodes and the medium and there is no charge flow in the medium where the currents are capacitive, i.e., are expressed only as rotation of charges, etc.
Turning now to FIG. 5 , the TC fields described above that have been found to advantageously destroy tumor cells are generated by an electronic apparatus 200 . FIG. 5 is a simple schematic diagram of the electronic apparatus 200 illustrating the major components thereof The electronic apparatus 200 generates the desired electric signals (TC signals) in the shape of waveforms or trains of pulses. The apparatus 200 includes a generator 210 and a pair of conductive leads 220 that are attached at one end thereof to the generator 210 . The opposite ends of the leads 220 are connected to insulated conductors 230 that are activated by the electric signals (e.g., waveforms). The insulated conductors 230 are also referred to hereinafter as isolects 230 . Optionally and according to another exemplary embodiment, the apparatus 200 includes a temperature sensor 240 and a control box 250 which are both added to control the amplitude of the electric field generated so as not to generate excessive heating in the area that is treated.
The generator 210 generates an alternating voltage waveform at frequencies in the range from about 50 kHz to about 500 kHz (preferably from about 100 kHz to about 300 kHz) (i.e., the TC fields). The required voltages are such that the electric field intensity in the tissue to be treated is in the range of about 0.1 V/cm to about 10 V/cm. To achieve this field, the actual potential difference between the two conductors in the isolects 230 is determined by the relative impedances of the system components, as described below.
When the control box 250 is included, it controls the output of the generator 210 so that it will remain constant at the value preset by the user or the control box 250 sets the output at the maximal value that does not cause excessive heating, or the control box 250 issues a warning or the like when the temperature (sensed by temperature sensor 240 ) exceeds a preset limit.
The leads 220 are standard isolated conductors with a flexible metal shield, preferably grounded so that it prevents the spread of the electric field generated by the leads 220 . The isolects 230 have specific shapes and positioning so as to generate an electric field of the desired configuration, direction and intensity at the target volume and only there so as to focus the treatment.
The specifications of the apparatus 200 as a whole and its individual components are largely influenced by the fact that at the frequency of the present TC fields (50 kHz-500 kHz), living systems behave according to their “Ohmic”, rather than their dielectric properties. The only elements in the apparatus 200 that behave differently are the insulators of the isolects 230 (see FIGS. 7-9 ). The isolects 200 consist of a conductor in contact with a dielectric that is in contact with the conductive tissue thus forming a capacitor.
The details of the construction of the isolects 230 is based on their electric behavior that can be understood from their simplified electric circuit when in contact with tissue as generally illustrated in FIG. 6 . In the illustrated arrangement, the electric field distribution between the different components is determined by their relative electric impedance, i.e., the fraction of the field on each component is given by the value of its impedance divided by the total circuit impedance. For example, the potential drop on element ?V A =A/(A+B+C+D+E). Thus, for DC or low frequency AC, practically all the potential drop is on the capacitor (that acts as an insulator). For relatively very high frequencies, the capacitor practically is a short and therefore, practically all the field is distributed in the tissues. At the frequencies of the present TC fields (e.g., 50 kHz to 500 kHz), which are intermediate frequencies, the impedance of the capacitance of the capacitors is dominant and determines the field distribution. Therefore, in order to increase the effective voltage drop across the tissues (field intensity), the impedance of the capacitors is to be decreased (i.e., increase their capacitance). This can be achieved by increasing the effective area of the “plates” of the capacitor, decrease the thickness of the dielectric or use a dielectric with high dielectric constant. There a number of different materials that are suitable for use in the intended application and have high dielectric constants. For example, some materials include: lithium niobate (LiNbO 3 ), which is a ferroelectric crystal and has a number of applications in optical, pyroelectric and piezoelectric devices; yttrium iron garnet (YIG) is a ferromagnetic crystal and magneto-optical devices, e.g., optical isolator can be realized from this material; barium titanate (BaTiO 3 ) is a ferromagnetic crystal with a large electro-optic effect; potassium tantalate (KTaO 3 ) which is a dielectric crystal (ferroelectric at low temperature) and has very low microwave loss and tunability of dielectric constant at low temperature; and lithium tantalate (LiTaO 3 ) which is a ferroelectric crystal with similar properties as lithium niobate and has utility in electro-optical, pyroelectric and piezoelectric devices. It will be understood that the aforementioned exemplary materials can be used in combination with the present device where it is desired to use a material having a high dielectric constant.
In order to optimize the field distribution, the isolects 230 are configured differently depending upon the application in which the isolects 230 are to be used. There are two principle modes for applying the present electric fields (TC fields). First, the TC fields can be applied by external isolects and second, the TC fields can be applied by internal isolects.
Electric fields (TC fields) that are applied by external isolects can be of a local type or widely distributed type. The first type includes, for example, the treatment of skin tumors and treatment of lesions close to the skin surface. FIG. 7 illustrates an exemplary embodiment where the isolects 230 are incorporated in a skin patch 300 . The skin patch 300 can be a self-adhesive flexible patch with one or more pairs of isolects 230 . The patch 300 includes internal insulation 310 (formed of a dielectric material) and the external insulation 260 and is applied to skin surface 301 that contains a tumor 303 either on the skin surface 301 or slightly below the skin surface 301 . Tissue is generally indicated at 305 . To prevent the potential drop across the internal insulation 310 to dominate the system, the internal insulation 310 must have a relatively high capacity. This can be achieved by a large surface area; however, this may not be desired as it will result in the spread of the field over a large area (e.g., an area larger than required to treat the tumor). Alternatively, the internal insulation 310 can be made very thin and/or the internal insulation 310 can be of a high dielectric constant. As the skin resistance between the electrodes (labeled as A and E in FIG. 6 ) is normally significantly higher than that of the tissue (labeled as C in FIG. 6 ) underneath it (1-10 kO vs. 0.1-1 kO), most of the potential drop beyond the isolects occurs there. To accommodate for these impedances (Z), the characteristics of the internal insulation 310 (labeled as B and D in FIG. 6 ) should be such that they have impedance preferably under 100 kO at the frequencies of the present TC fields (e.g., 50 kHz to 500 kHz). For example, if it is desired for the impedance to be about 10K Ohms, such that over 1% of the applied voltage falls on the tissues, for isolects with a surface area of 10 mm 2 , at frequencies of 200 kHz, the capacity should be on the order of 10 −10 F, which means that using standard insulations with a dielectric constant of 2-3, the thickness of the insulating layer 310 should be about 50-100 microns. An internal field 10 times stronger would be obtained with insulators with a dielectric constant of about 20-50.
Since the insulating layer can be very vulnerable, etc., the insulation can be replaced by very high dielectric constant insulating materials, such as titanium dioxide (e.g., rutil), the dielectric constant can reach values of about 200. One must also consider another factor that effects the effective capacity of the isolects 230 , namely the presence of air between the isolects 230 and the skin. Such presence, which is not easy to prevent, introduces a layer of an insulator with a dielectric constant of 1.0, a factor that significantly lowers the effective capacity of the isolects 230 and neutralizes the advantages of the titanium dioxide (rutil), etc. To overcome this problem, the isolects 230 can be shaped so as to conform with the body structure and/or (2) an intervening filler 270 (as illustrated in FIG. 1C ), such as a gel, that has high conductance and a dielectric constant, can be added to the structure. The shaping can be pre-structured (see FIG. 10A ) or the system can be made sufficiently flexible so that shaping of the isolects 230 is readily achievable. The gel can be contained in place by having an elevated rim as depicted in FIG. 10C . The gel can be made of gelatins, agar, etc., and can have salts dissolved in it to increase its conductivity. FIGS. 10A-10C illustrate various exemplary configurations for the isolects 230 . The exact thickness of the gel is not important so long as it is of sufficient thickness that the gel layer does not dry out during the treatment. In one exemplary embodiment, the thickness of the gel is about 0.5 mm to about 2 mm.
In order to achieve the desirable features of the isolects 230 , the dielectric coating of each should be very thin, for example from between 1-50 microns. Since the coating is so thin, the isolects 230 can easily be damaged mechanically. This problem can be overcome by adding a protective feature to the isolect's structure so as to provide desired protection from such damage. For example, the isolect 230 can be coated, for example, with a relatively loose net 340 that prevents access to the surface but has only a minor effect on the effective surface area of the isolect 230 (i.e., the capacity of the isolects 230 (cross section presented in FIG. 12B ). The loose net 340 does not effect the capacity and ensures good contact with the skin, etc. The loose net 340 can be formed of a number of different materials; however, in one exemplary embodiment, the net 340 is formed of nylon, polyester, cotton, etc. Alternatively, a very thin conductive coating 350 can be applied to the dielectric portion (insulating layer) of the isolect 230 . One exemplary conductive coating is formed of a metal and more particularly of gold. The thickness of the coating 350 depends upon the particular application and also on the type of material used to form the coating 350 ; however, when gold is used, the coating has a thickness from about 0.1 micron to about 0.1 mm. Furthermore, the rim illustrated in FIG. 10 can also provide some mechanical protection.
However, the capacity is not the only factor to be considered. The following two factors also influence how the isolects 230 are constructed. The dielectric strength of the internal insulating layer 310 and the dielectric losses that occur when it is subjected to the TC field, i.e., the amount of heat generated. The dielectric strength of the internal insulation 310 determines at what field intensity the insulation will be “shorted” and cease to act as an intact insulation. Typically, insulators, such as plastics, have dielectric strength values of about 100V per micron or more. As a high dielectric constant reduces the field within the internal insulator 310 , a combination of a high dielectric constant and a high dielectric strength gives a significant advantage. This can be achieved by using a single material that has the desired properties or it can be achieved by a double layer with the correct parameters and thickness. In addition, to further decreasing the possibility that the insulating layer 310 will fail, all sharp edges of the insulating layer 310 should be eliminated as by rounding the corners, etc., as illustrated in FIG. 10D using conventional techniques.
FIGS. 8 and 9 illustrate a second type of treatment using the isolects 230 , namely electric field generation by internal isolects 230 . A body to which the isolects 230 are implanted is generally indicated at 311 and includes a skin surface 313 and a tumor 315 . In this embodiment, the isolects 230 can have the shape of plates, wires or other shapes that can be inserted subcutaneously or a deeper location within the body 311 so as to generate an appropriate field at the target area (tumor 315 ).
It will also be appreciated that the mode of isolects application is not restricted to the above descriptions. In the case of tumors in internal organs, for example, liver, lung, etc., the distance between each member of the pair of isolects 230 can be large. The pairs can even by positioned opposite sides of a torso 410 , as illustrated in FIG. 11 . The arrangement of the isolects 230 in FIG. 11 is particularly useful for treating a tumor 415 associated with lung cancer. In this embodiment, the electric fields (TC fields) spread in a wide fraction of the body.
In order to avoid overheating of the treated tissues, a selection of materials and field parameters is needed. The isolects insulating material should have minimal dielectric losses at the frequency ranges to be used during the treatment process. This factor can be taken into consideration when choosing the particular frequencies for the treatment. The direct heating of the tissues will most likely be dominated by the heating due to current flow (given by the I*R product).
The effectiveness of the treatment can be enhanced by an arrangement of isolects 230 that focuses the field at the desired target while leaving other sensitive areas in low field density (i.e., protected areas). The proper placement of the isolects 230 over the body can be maintained using any number of different techniques, including using a suitable piece of clothing that keeps the isolects at the appropriate positions. FIG. 13 illustrates such an arrangement in which an area labeled as “P” represents a protected area. The lines of field force do not penetrate this protected area and the field there is much smaller than near the isolects 230 where target areas can be located and treated well. In contrast, the field intensity near the four poles is very high.
The following Example serves to illustrate an exemplary application of the present apparatus and application of TC fields; however, this Example is not limiting and does not limit the scope of the present invention in any way.
EXAMPLE
To demonstrate the effectiveness of electric fields having the above described properties (e.g., frequencies between 50 kHz and 500 kHz) in destroying tumor cells, the electric fields were applied to treat mice with malignant melanoma tumors. Two pairs of isolects 230 were positioned over a corresponding pair of malignant melanomas. Only one pair was connected to the generator 210 and 200 kHz alternating electric fields (TC fields) were applied to the tumor for a period of 6 days. One melanoma tumor was not treated so as to permit a comparison between the treated tumor and the non-treated tumor. After treatment for 6 days, the pigmented melanoma tumor remained clearly visible in the non-treated side of the mouse, while, in contrast, no tumor is seen on the treated side of the mouse. The only areas that were visible discernable on the skin were the marks that represented the points of insertion of the isolects 230 . The fact that the tumor was eliminated at the treated side was further demonstrated by cutting and inversing the skin so that its inside face was exposed. Such a procedure indicated that the tumor has been substantially, if not completely, eliminated on the treated side of the mouse. The success of the treatment was also further verified by pathhistological examination.
The present inventor has thus uncovered that electric fields having particular properties can be used to destroy dividing cells or tumors when the electric fields are applied to using an electronic device. More specifically, these electric fields fall into a special intermediate category, namely bio-effective fields that have no meaningful stimulatory and no thermal effects, and therefore overcome the disadvantages that were associated with the application of conventional electric fields to a body. It will also be appreciated that the present apparatus can further include a device for rotating the TC field relative to the living tissue. For example and according to one embodiment, the alternating electric potential applies to the tissue being treated is rotated relative to the tissue using conventional devices, such as a mechanical device that upon activation, rotates various components of the present system.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the invention.
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Dividing cells within living tissue that contain polarizable intracellular members can be destroyed using at least two insulated electrodes and an electric field source that applies an alternating electric potential across the conductors within the insulated electrodes. The electric field is transformed into a non-homogenous electric field that produces an increased density electric field in a region of the dividing cells. The non-homogenous electric field is of sufficient intensity to cause the intracellular members to be drawn to that region, which causes a pressure increase that results in a structural breakdown of the dividing cells.
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BACKGROUND
The present invention relates to thermosensitive, thermo-reversible pharmaceutical compositions. In particular, the present invention relates to sustained release, gelable (thermosensitive) botulinum toxin pharmaceutical compositions formulated with a poloxamer.
A pharmaceutical composition is a formulation which contains at least one active ingredient (such as a botulinum toxin) as well as, for example, one or more excipients, buffers, carriers, stabilizers, preservatives and/or bulking agents, and is suitable for administration to a patient to achieve a desired diagnostic result or therapeutic effect. The pharmaceutical compositions disclosed herein have diagnostic, therapeutic, cosmetic and/or research utility.
For storage stability and convenience of handling, a pharmaceutical composition can be formulated as a lyophilized (i.e. freeze dried) or vacuum dried powder which can be reconstituted with a suitable fluid, such as saline or water, prior to administration to a patient. Alternately, the pharmaceutical composition can be formulated as a ready to use aqueous solution or suspension. A pharmaceutical composition can contain a proteinaceous active ingredient. Unfortunately, a protein active ingredient can be very difficult to stabilize (i.e. maintained in a state where loss of biological activity is minimized), resulting therefore in a loss of protein and/or loss of protein activity during the formulation, reconstitution (if required) and during the period of storage prior to use of a protein containing pharmaceutical composition. Stability problems can occur because of protein denaturation, degradation, dimerization, and/or polymerization. Various excipients, such as albumin and gelatin have been used with differing degrees of success to try and stabilize a protein active ingredient present in a pharmaceutical composition. Additionally, cryoprotectants such as alcohols have been used to reduce protein denaturation under the freezing conditions of lyophilization.
Thermosensitive pharmaceutical compositions, which form in-situ gels, are known. See e.g. U.S. Pat. No. 5,278,201. Poloxamers are nontoxic block copolymers of poly(ethylene oxide), poly(propylene oxide) and poly(ethylene oxide) (PEO-PPO-PEO). Certain poloxamers exhibit reversible thermal gelation. Thus a solution of a protein and a poloxamer prepared at low temperatures and injected will form a gel as it warms to body temperature. Subsequently the protein is slowly released from the gel. A gelable, thermo-reversible formulation comprising poloxamer 407 at a 22 wt % concentration has been prepared with the model protein drugs α-chymotrypsin and lactate dehydrogenase. Stratton L., et al., Drug delivery matrix containing native protein precipitates suspended in a poloxamer gel , J Pharm Sci 86(9); 1006-1010, September 1996. Formulations of certain adhesive proteins and poloxamer 127 have been made. Huang K., et al., Synthesis and characterization of self assembling block copolymers containing adhesive moieties , Polymer Preprints 2001, 42(2), 147-148. Additionally, poloxamer 188 and poloxamer 407 have been used an excipients in protein drug pharmaceutical compositions. Jeong B., et al., Thermosensitive sol - gel reversible hydrogels , Adv Drug Del Rev, 54(1); 37-51, Jan. 17, 2002. Published patent application WO 2007/041664 discloses use a pharmaceutical composition comprising a botulinum toxin and a poloxamer 188.
Botulinum toxins have been used for various therapeutic and cosmetic purposes including treating cervical dystonia, blepharospasm, strabismus, spasticity, headache, hyperhidrosis, overactive bladder, rhinitis, bruxism, enlarged prostate, achalasia, anismus, sphincter of Oddi malfunction, acne, tremors, juvenile cerebral palsy, and facial wrinkles.
Commercially available botulinum toxin containing pharmaceutical compositions include BOTOX® (Botulinum toxin type A neurotoxin complex with human serum albumin and sodium chloride) available from Allergan, Inc., of Irvine, Calif. in 100 unit vials as a lyophilized powder to be reconstituted with 0.9% sodium chloride before use), DYSPORT® (Clostridium botulinum type A toxin haemagglutinin complex with human serum albumin and lactose in the formulation), available from Ipsen Limited, Berkshire, U.K. as a powder to be reconstituted with 0.9% sodium chloride before use), and MYOBLOC™ (an injectable solution comprising botulinum toxin type B, human serum albumin, sodium succinate, and sodium chloride at about pH 5.6, available from Solstice Neurosciences, Inc., South San Francisco, Calif.).
Botulinum toxin is a large protein for incorporation into a pharmaceutical formulation (the molecular weight of the botulinum toxin type A complex is 900 kD) and is inherently fragile and labile. The size of the toxin complex makes it much more friable and labile than smaller, less complex proteins, thereby compounding the formulation and handling difficulties if botulinum toxin stability is to be maintained. Hence, a botulinum toxin stabilizer must be able to interact with the toxin in a manner which does not denature, fragment or otherwise detoxify the toxin molecule or cause disassociation of the non-toxin proteins present in the toxin complex.
As the most lethal known biological product, exceptional safety, precision, and accuracy are called for at all steps of the formulation of a botulinum toxin containing pharmaceutical composition. Thus, a botulinum toxin stabilizer should not itself be toxic or difficult to handle so as to not exacerbate the already extremely stringent botulinum toxin containing pharmaceutical composition formulation requirements.
Since botulinum toxin was the first microbial toxin to be approved (by the U.S. Food and Drug Administration in 1989) for injection for the treatment of human disease, specific protocols had to be developed and approved for the culturing, bulk production, formulation into a pharmaceutical and use of botulinum toxin. Important considerations are toxin purity and dose for injection. The production by culturing and the purification must be carried out so that the toxin is not exposed to any substance that might contaminate the final product in even trace amounts and cause undue reactions in the patient. These restrictions require culturing in simplified medium without the use of animal meat products and purification by procedures not involving synthetic solvents or resins. Preparation of toxin using enzymes, various exchangers, such as those present in chromatography columns and synthetic solvents, can introduce contaminants and are therefore excluded from preferred formulation steps. Furthermore, botulinum toxin type A is readily denatured at temperatures above 40 degrees Centigrade, loses toxicity when bubbles form at the air/liquid interface and denatures in the presence of nitrogen or carbon dioxide.
Particular difficulties exist to stabilize botulinum toxin type A, because type A consists of a toxin molecule of about 150 kD in noncovalent association with nontoxin proteins weighing about 750 kD. The nontoxin proteins are believed to preserve or help stabilize the secondary and tertiary structures upon which toxicity is dependant. Procedures or protocols applicable to the stabilization of nonproteins or to relatively smaller proteins are not applicable to the problems inherent with stabilization of the botulinum toxin complexes, such as the 900 kD botulinum toxin type A complex. Thus while from pH 3.5 to 6.8 the type A toxin and non toxin proteins are bound together noncovalently, under slightly alkaline conditions (pH >7.1) the very labile about 150 kD neurotoxic component of a botulinum toxin is released from the botulinum toxin complex. XEOMIN® is the trade name for a neurotoxic component botulinum toxin type A pharmaceutical composition available from Merz Pharmaceuticals (Frankfurt, Germany).
In some instances botulinum toxins, when used as therapeutic drugs, are known to migrate from the site of injection at various rates and distances, sometimes resulting in loss of effect at the desired muscle.
Solid botulinum toxin implants are known. See e.g., U.S. Pat. Nos. 6,306,423; 6,312,708, for a discussion of exemplary solid implants and applications. Additionally formulation of a botulinum toxin in a viscous carrier such as a hyaluronic acid is known; U.S. application Ser. Nos. 11/954,629, and 11/954,602, filed Dec. 12, 2007.
What is needed is a biocompatible, gelable (thermoplastic) pharmaceutical composition comprising a stabilized botulinum toxin so that the composition can be administered as a liquid yet forms a sustained release gel upon administration; thereby localizing the effect and controlling release of the toxin to enhance the effect per dose.
SUMMARY
The present invention fulfills this need and provides a gelable, thermoreversible, thermoplastic botulinum toxin pharmaceutical composition that can be administered as a liquid and form a gel from which the botulinum toxin exhibits a sustained release upon administration of the pharmaceutical composition. Additionally, the present invention provides the additional advantage in that the compound which provides the thermo-reversible characteristic to the composition can also stabilize the botulinum toxin present in the pharmaceutical composition.
In one embodiment the present invention provides a thermoplastic thermoreversible, botulinum toxin pharmaceutical composition formulated with a poloxamer. Importantly, besides providing the thermoreversible, thermoplastic characteristics of the pharmaceutical composition the poloxamer can also act to stabilize the botulinum toxin.
DEFINITIONS
As used herein the words or terms set forth below have the following meaning.
“About” means that the item, parameter or term so qualified encompasses a range of plus or minus ten percent above and below the value of the stated item, parameter or term.
“Administration”, or “to administer” means the step of giving (i.e. administering) a pharmaceutical composition to a subject. The pharmaceutical compositions disclosed herein are “locally administered” by e.g. intramuscular (i.m.), intradermal, subcutaneous administration, intrathecal administration, intraperitoneal (i.p.) administration, topical (transdermal) and implantation (i.e. of a slow-release device) routes of administration.
“Botulinum toxin” means: (1) a neurotoxin produced by Clostridium botulinum, as well as a botulinum toxin (or the light chain or the heavy chain thereof) made recombinantly by a non-Clostridial species; (2) the botulinum toxin serotypes A, B, C, D, E, F and G; (3) a botulinum toxin complex (i.e. the 300, 600 and 900 kDa complexes) as well as the neurotoxic component of a purified botulinum toxin (i.e. about 150 kDa), or; (4) a modified botulinum toxin, a pegylated (with a PEG), chimeric, recombinant, hybrid, wild-type botulinum toxins, botulinum toxin constructs, endopeptidases, chemically-modified botulinum toxins (pegylated botulinum toxin), and retargeted botulinum toxin, which retains the intracellular ability to inhibit acetylcholine release from a cell.
“Entirely free” (i.e. “consisting of” terminology) means that within the detection range of the instrument or process being used, the substance cannot be detected or its presence cannot be confirmed.
“Essentially free” (or “consisting essentially of”) means that only trace amounts of the substance can be detected.
“Modified botulinum toxin” means a botulinum toxin that has had at least one of its amino acids deleted, modified, or replaced, as compared to a native botulinum toxin. Additionally, the modified botulinum toxin can be a recombinantly produced neurotoxin, or a derivative or fragment of a recombinantly made neurotoxin. A modified botulinum toxin retains at least one biological activity of the native botulinum toxin, such as, the ability to bind to a botulinum toxin receptor, or the ability to inhibit neurotransmitter release from a neuron. One example of a modified botulinum toxin is a botulinum toxin that has a light chain from one botulinum toxin serotype (such as serotype A), and a heavy chain from a different botulinum toxin serotype (such as serotype B). Another example of a modified botulinum toxin is a botulinum toxin coupled to a neurotransmitter, such as substance P.
“Pharmaceutical composition” means a formulation in which an active ingredient can be a Clostridial neurotoxin, such as a botulinum toxin. The word “formulation” means that there is at least one additional ingredient in the pharmaceutical composition besides a Clostridial neurotoxin active ingredient. A pharmaceutical composition is therefore a formulation which is suitable for diagnostic, therapeutic or cosmetic use (i.e. by intramuscular or subcutaneous injection or by insertion of a depot or implant or topical application) to a subject, such as a human patient. The pharmaceutical composition can be in a lyophilized or vacuum dried condition; a solution formed after reconstitution of the lyophilized or vacuum dried pharmaceutical composition with saline or water, or; as a solution which does not require reconstitution. As stated, a pharmaceutical composition can be liquid or solid, for example vacuum-dried. The constituent ingredients of a pharmaceutical composition can be included in a single composition (that is all the constituent ingredients, except for any required reconstitution fluid, are present at the time of initial compounding of the pharmaceutical composition) or as a two-component system, for example a vacuum-dried composition reconstituted with a diluent such as saline which diluent contains an ingredient not present in the initial compounding of the pharmaceutical composition. A two-component system provides the benefit of allowing incorporation of ingredients which are not sufficiently compatible for long-term shelf storage with the first component of the two component system. For example, the reconstitution vehicle or diluent may include a preservative which provides sufficient protection against microbial growth for the use period, for example one-week of refrigerated storage, but is not present during the two-year freezer storage period during which time it might degrade the toxin. Other ingredients, which may not be compatible with a Clostridial toxin or other ingredients for long periods of time, may be incorporated in this manner; that is, added in a second vehicle (i.e. in the reconstitution fluid) at the approximate time of use.
“Sustained release” means that the therapeutic agent (i.e. a botulinum toxin) contained by a pharmaceutical composition (such as a pharmaceutical composition comprising a poloxamer) is released from the pharmaceutical composition over a period of time between about 5 days and about 1 year.
“Stabilizer” (or “primary stabilizer”) is a compound that assists to preserve or maintain the biological structure (i.e. the three dimensional conformation) and/or biological activity of a protein (such as a botulinum toxin). More than one stabilizer can be included in a pharmaceutical composition. Examples of stabilizers are surfactants, polymers, polyols, a poloxamer, albumin, gelatin, trehalose, proteins, sugars, polyvinylpyrrolidone, N-acetyl-tryptophan (“NAT”)), caprylate (i.e. sodium caprylate), a polysorbate (i.e. P80), amino acids, and divalent metal cations such as zinc. A pharmaceutical composition can also include a preservative such as a benzyl alcohol, cresols, benzoic acid, phenol, parabens and sorbic acid.
“Stabilizing”, “stabilizes”, or “stabilization” mean that an active pharmaceutical ingredient (“API”) retains at least 20% and up to 100% of its biological activity (which can be assessed as potency or as toxicity by an in vivo LD 50 or ED 50 measure) in the presence of a compound which is stabilizing, stabilizes or which provides stabilization to the API. For example, upon (1) preparation of serial dilutions from a bulk or stock solution, or (2) upon reconstitution with saline or water of a lyophilized, or vacuum dried botulinum toxin containing pharmaceutical composition which has been stored at or below about −2 degrees C. for between six months and four years, or (3) for an aqueous solution botulinum toxin containing pharmaceutical composition which has been stored at between about 2 degrees and about 8 degrees C. for from six months to four years, the botulinum toxin present in the reconstituted or aqueous solution pharmaceutical composition has (in the presence of a compound which is stabilizing, stabilizes or which provides stabilization to the API) greater than about 20% and up to about 100% of the potency or toxicity that the biologically active botulinum toxin had prior to being incorporated into the pharmaceutical composition.
“Substantially free” means present at a level of less than one percent by weight of the pharmaceutical composition.
“Therapeutic agent” means an active pharmaceutical ingredient (API) which can have therapeutic, cosmetic, and/or research use or benefit when administered to a patient. The therapeutic agent can be for example a steroid, antibiotic, or protein.
“Thermoplastic” is synonymous with “thermosensitive” and means a compound or composition which is a liquid or a low viscosity solution (i.e. viscosity less that 500 cps at 25° C. at a shear rate of about 0.1/second) at a low temperature (between about 0° C. to about 10° C.), but which is a higher viscosity ((i.e. viscosity less that 10,000 cps at 25° C. at a shear rate of about 0.1/second) gel at a higher temperature (between about 30° C. to about 40° C. such as at about 37° C.)
In particular embodiments, a thermoplastic, thermoreversible, pharmaceutical composition is disclosed comprising a biologically active botulinum toxin, and a thermoplastic poloxamer, where the poloxamer stabilizes the botulinum toxin so that the botulinum toxin retains biological activity upon release of the botulinum toxin from the pharmaceutical composition in vivo. The botulinum toxin is selected from the group consisting of the botulinum toxins types A, B, C 1 , D, E, F and G and is preferably a botulinum toxin type A, known for its long lasting effect. An exemplary thermo-reversible poloxamer is a poloxamer 407, an example of which can be obtained from the BASF Corporation, Parsippany, N.J., under the name F-127.
In some embodiments, the poloxamer can be present at a concentration of from about 15 wt % to about 25 wt % of the pharmaceutical composition.
In one specific embodiment, the thermoreversible, thermoplastic, pharmaceutical composition comprises a biologically active botulinum toxin type A and a thermoplastic poloxamer 407 present at a concentration of about 15 wt % to about 25 wt % of the pharmaceutical composition, which stabilizes the botulinum toxin so that the botulinum toxin retains biological activity upon release of the botulinum toxin from the pharmaceutical composition in vivo.
A method for treating a medical or cosmetic condition is also disclosed herein, the method comprising the step of administering to a patient a thermoplastic, thermo-reversible pharmaceutical composition comprising a biologically active botulinum toxin and a thermoplastic, thermoreversible, poloxamer such that the poloxamer stabilizes the botulinum toxin so that the botulinum toxin retains biological activity upon release of the botulinum toxin from the pharmaceutical composition in vivo and the pharmaceutical composition is administered as a liquid and becomes a gel after the administration, to provide therapeutic amounts of the botulinum toxin released from the composition in vivo for at least 1 week after the administration. The thermoreversible, thermoplastic is a poloxamer 407 and is present at a concentration of about 15 wt % to about 25 wt % of the pharmaceutical composition. In some methods, a step of placing a cooling or heating element (such as, for example, a hot or cold pad, bottle, packet of ice or warm water and the like) is placed over an area of administration, before or after the administration step, in order to warm or cool the area to decrease or increase the viscosity of the administered thermoplastic, thermoreversible, pharmaceutical composition in situ and after its administration to the patient.
Exemplary medical conditions that can be so treated include glabellar lines, crows feet, marionette lines, nasolabial lines, horizontal lines of the forehead or any combination thereof. Additional exemplary medical or cosmetic conditions include treating at least one of overactive bladder, hyperhidrosis, benign prostatic hyperplasia and a dystonia, where the botulinum toxin is selected from the group consisting of the botulinum toxins types A, B, C 1 , D, E, F and G. As above, the preferred botulinum toxin is botulinum toxin type A.
In particular embodiments, the botulinum toxin type A is present in the thermoreversible, thermoplastic, pharmaceutical composition in an amount from about 5 units to about 2750 units. The total amount (units) of a botulinum toxin to be administered to a patient is determined by the attending medical professional.
Also herein disclosed is a process for making a thermoreversible, thermoplastic, gelable, pharmaceutical composition, comprising the steps of dissolving a thermoplastic poloxamer in a solvent at a temperature below about 37 degrees Centigrade, adding and mixing a botulinum toxin to the thermoplastic poloxamer in the solvent to thoroughly disperse the botulinum toxin therein. The poloxamer can be present in particular embodiments at a concentration from about 15 wt % to about 25 wt % of the pharmaceutical composition, thereby making the thermoplastic, gelable, pharmaceutical composition.
In a particular process for making the thermoreversible, thermoplastic, gelable pharmaceutical composition, a botulinum toxin type A or B is utilized. An exemplary amount added can be from about 1 to about 2000 units of the botulinum toxin type A or from about 50 to about 25,000 units of a botulinum toxin type B, to be administered to a patient in need thereof. The process can also include adding an additive, for preservative or stabilizing purposes, for example, to form the final thermoplastic, gelable, pharmaceutical composition. In specific examples, the solvent utilized in the method of making the thermoplastic, gelable, pharmaceutical composition is water or a saline solution and the process of making the thermoplastic, gelable, pharmaceutical composition is carried out within a cold room having an temperature of below about 37 degrees Centigrade, or between about 0 to about 8 degrees Centigrade, for example.
Also disclosed are methods for treating a medical or cosmetic condition, that comprise the steps of administering to a patient a thermoreversible, thermoplastic, pharmaceutical composition that includes a biologically active botulinum toxin and a thermoreversible, thermoplastic poloxamer, wherein the poloxamer stabilizes the botulinum toxin and is a gel at room temperature (e.g. the temperature of an enclosed space at which human beings are usually accustomed, e.g. from about 17° C. to about 25° C. Before administration, the pharmaceutical composition is cooled below the room temperature to reduce its viscosity (liquefy) the pharmaceutical composition and is thereafter drawn into a syringe and injected into the patient, where the thermoplastic pharmaceutical composition gels to deliver therapeutic amounts of the botulinum toxin are released from the composition in vivo for at least 1 week after administration. In particular embodiments, the thermoplastic poloxamer is a poloxamer 407 and is present at a concentration of about 15 wt % to about 25 wt % of the pharmaceutical composition.
The thermoplastic, pharmaceutical composition is thermo-reversible, that is, its viscosity can be increased and/or decreased based on temperature, and is reversible. For example, the thermoreversible, thermoplastic poloxamer such as poloxamer 407 at about 20% wt (and hence the thermoplastic, pharmaceutical composition) can have a first viscosity at a first temperature (e.g. from about 0 centipoise (cP) at about 0 to about 16 degrees Centigrade), have its temperature raised to increase its viscosity to a second viscosity that is higher relative to the first viscosity (e.g. from about 50 cP to about 6000 cP at about 18 to about 22 degrees Centigrade), and then is reversible, e.g. lowering its temperature, decreasing its viscosity relative to the second viscosity, for example. A change in weight % of poloxamer 407 in a composition will alter its viscosity/temperature profile.
Each and every feature described herein, and each and every combination of two or more of such features, is included within the scope of the present invention, provided that the features included in such a combination are not mutually inconsistent.
DESCRIPTION
I have discovered new thermo-reversible depot pharmaceutical compositions (formulations) for a botulinum toxin. My invention is based on the discovery that certain thermo-reversible poloxamers show remarkable compatibility with botulinum toxins. These depot systems can be thermally manipulated (pre & post injection) to control migration and distribution of the botulinum toxin. No combinations of botulinum toxins and poloxamer 407 are known.
A formulation within the scope of my invention is administered as a liquid and the polymer gels (cures) in situ at the site of local administration.
An embodiment of my invention can comprise a triblock PEO-PPO-PEO copolymer compounds, also known as pluronics or poloxamers, which at certain concentrations can form thermo-reversible gels which can be administered (as by injection) as a low viscosity liquid that rapidly increases in viscosity after injection. The resulting high viscosity matrix is adhesive, biodegradable and biocompatible and upon administration forms a depot from which the botulinum toxin can be released, thereby providing a sustained or extended release drug delivery system. In this manner a lower dose of the botulinum toxin can be used. Such a pharmaceutical composition can be administered pre-mixed or as a simple reconstitution vehicle or its several compartments combined at the time of administration, as by use of a dual chamber syringe.
I have found that botulinum neurotoxins are very stable in poloxamers, such as poloxamer 407, for example. This is surprising because of the complex structural nature of these toxins. For example, three separate protein domains (binding, translocation, enzymatic) must be conserved in order to maintain biological activity of the naked 150 kD toxin. Surfactants are chaotropic and therefore generally disrupt protein conformations. It is therefore surprising to find compatibility between these molecules and surfactants. The 900 kD toxins are protein complexes with neurotoxin associated proteins (NAPs), which stabilize the 150 kD portion. Surfactants would be expected to disrupt the protein complex, thereby destabilizing the complex and/or denaturing the 150 kD toxin portion.
The thermo-reversible poloxamer used in the present invention can apparently impart stability to a neurotoxin active ingredient, such as a botulinum toxin, present in the pharmaceutical composition by: (1) reducing adhesion (commonly referred to as “stickiness”) of the botulinum toxin to surfaces, including the surfaces of laboratory glassware, vessels, the vial in which the pharmaceutical composition is reconstituted and the inside surface of the syringe used to inject the pharmaceutical composition. Adhesion of the botulinum toxin to surfaces can lead to loss of botulinum toxin and to denaturation of retained botulinum toxin, both of which reduce the toxicity of the botulinum toxin present in the pharmaceutical composition; (2) reducing the denaturation of the botulinum toxin and/or dissociation of the botulinum toxin from other non-toxin proteins present in the botulinum toxin complex, which denaturation and/or dissociation activities can occur because of the low dilution of the botulinum toxin present in the pharmaceutical composition (i.e. prior to lyophilization or vacuum drying) and in the reconstituted pharmaceutical composition; (3) reducing loss of botulinum toxin (i.e. due to denaturation or dissociation from non-toxin proteins in the complex) during the considerable pH and concentration changes which take place during preparation, processing and reconstitution of the pharmaceutical composition; (4) immobilizing the toxin in a high-viscosity vehicle; and (5) protecting the toxin from deleterious effects of elevated physiologic temperature (about 37° C.) and pH by providing a beneficial micro-environment.
The five types of botulinum toxin stabilizations provided by the poloxamers disclosed herein conserve and preserve the botulinum toxin and with it native toxicity of the toxin present in the pharmaceutical composition.
My invention also encompasses addition of a preservative, either in the diluent or formulation itself, to allow extended storage. A preferred preservative is preserved saline containing benzyl alcohol.
The thermo-reversible pharmaceutical compositions of the invention can be administered using conventional modes of administration. In particular embodiments of the invention, the compositions are administered intradermally, intramuscularly or subcutaneously to the patient. In addition, the compositions of the invention may be administered with one or more analgesic or anesthetic agents.
The most effective mode of administration and dosage regimen for the compositions of this invention depends upon the type, severity, and course of the condition being treated, the patient's health and response to treatment, and the judgment of the treating physician. Accordingly, the methods and dosages of the compositions can be tailored to the individual patient.
Compositions containing other serotypes of botulinum toxin may contain different doses (unit amounts) of the botulinum toxin. For example, botulinum toxin type B can be provided in a composition at a greater dose (about 50×) than a composition containing botulinum toxin type A. In one embodiment of the invention, botulinum toxin type B may be administered in an amount between about 1 U/kg and 150 U/kg. Botulinum toxin type B may also be administered in amounts of up to 20,000 U (mouse units, as described above). In another embodiment of the invention, botulinum toxin types E or F may be administered at concentrations between about 0.1 U/kg and 150 U/kg. In addition, in compositions containing more than one type of botulinum toxin, each type of botulinum toxin can be provided in a relatively smaller dose than the dose typically used for a single botulinum toxin serotype.
EXAMPLES
The following examples set forth specific embodiments of the present invention and are not intended to limit the scope of the invention.
In the Examples below the well known mouse lethal dose 50 assay (the “MLD50 assay”) was used to determine the potency of the botulinum toxin released from the poloxamer formulations made. Depending on the circumstances, “potency” can mean the recovered potency of the botulinum toxin or the potency of the botulinum toxin prior to lyophilization. Recovered potency is synonymous with reconstitution potency, recovery potency and with potency upon reconstitution. The MLD50 assay provides a determination of the potency of a botulinum toxin in terms of its mouse 50% lethal dose or “LD50”. Thus, one unit (U) of a botulinum toxin is defined as the amount of botulinum toxin which upon intraperitoneal injection kills 50% (i.e. a LD 50 ) of a group of female Swiss Weber mice weighing 17-22 grams each at the start of the assay. The MLD50 assay is a validated method for measuring the potency of a reconstituted botulinum toxin or of a reconstituted botulinum toxin formulation. Each mouse is held in a supine position with its head tilted down and is injected intraperitoneally into the lower right abdomen at an angle of about 30 degrees using a 25 to 27 gauge ⅜″ to ⅝″ needle with one of several serial dilutions of the botulinum toxin in normal saline. The death rates over the ensuing 72 hours for each dilution are recorded. A minimum of six dilutions at 1.33 dose intervals are prepared and typically ten animals are used in each dosage group (60 mice employed therefore). Two reference standard assays are carried out concurrently (additional 60 mice employed). The dilutions are prepared so that the most concentrated dilution produces a death rate of at least 80% of the mice injected, and the least concentration dilution produces a death rate no greater than 20% of the mice injected. There must be a minimum of four dilutions that fall within the monotone decreasing range of the death rates. The monotone decreasing range commences with a death rate of no less than 80%. Within the four or more monotone decreasing rates, the two largest and the two smallest rates must be decreasing (i.e. not equivalent). The dilution at which 50% of the mice die within the three day post injection observation period is defined as a dilution which comprises one unit (1 U) of the botulinum toxin. A refined MLD50 assay has been developed which uses fewer (five instead of six) dilutions at 1.15 dose intervals and fewer mice (six instead of ten) per dilution tested.
Example 1
Botulinum Toxin-Poloxamer 407 Formulations
Experiments were carried out in which a number of botulinum toxin-poloxamer formulations were made and assessed. The botulinum toxin used in each of the formulations made was lyophilized BOTOX®. The amount of the botulinum toxin used in each of the formulations made in 100 units of botulinum toxin type A (BOTOX®).
The poloxamer used in this example was poloxamer 407 obtained from BASF (Lutrol F-127). In each formulation, the poloxamer 407 was used in an amount that constituted 20 weight percent (wt %) of the final formulation. Poloxamer 407 is supplied as dry powder and is a hydrophilic non-ionic surfactant and a triblock copolymer consisting of two hydrophilic blocks (polyethylene glycol) separated by a hydrophobic block (poly-propylene glycol). The lengths of the two PEG blocks is about 101 repeating units, while the length of the propylene glycol block is about 56 repeating units. Solutions of Poloxamer 407, at appropriate concentrations, are liquid under refrigeration, but gel at room temperature and above (e.g., is a gel at about 37° C.). Poloxamer 407 can therefore be reconstituted or stored as a low-viscosity liquid for easy passage through a needle but then gels into a depot after injection into a mammal as it is subjected to increasing temperature. Poloxamer 407 was chosen for the formulations made in this example because of these desirable physical properties combined with unusual toxin compatibility.
Each formulation was made by a process which combines the solids (recall that the Poloxamer 407 is supplied as dry powder) in large centrifuge tubes with water or saline (inside a cold room at about 2 to about 8 degrees Centigrade) and is mixed with a magnetic stir bar, until fully dissolved.
The solutions are stored at from about 4 to about 15 degrees Centigrade until injected/used. The solutions were then used to reconstitute a botulinum toxin type A (BOTOX®) in vials containing 100 units (U), by introducing the cold solution into the vials with a syringe.
Samples were then heated to 37° C. until gelled to simulate injection into a warm body.
Significantly I determined that the thermo-reversible formulations can be made with from 15-25 wt % poloxamer 407 (available from BASF as Lutrol F-127) without significant attenuation of the desired formulation characteristics of (1) thermoplasticity, and (2) sustained release of biologically active botulinum toxin from the formulations made.
As set forth below, 26 different thermo-reversible poloxamer formulations were made. Each of the 26 formulation made included 20 wt % poloxamer 407 and 100 units of botulinum toxin type A (BOTOX®):
1. 20% Poloxamer 407 in SWFI (sterile water for injection) 2. 20% Poloxamer 407 in 0.9% sodium chloride 3. 20% Poloxamer 407 in preserved (benzyl alcohol) 0.9% sodium chloride 4. 20% Poloxamer 407 with 5% Poloxamer 188 5. 20% Poloxamer 407 with 3% Tween 6. 20% Poloxamer 407 with 5% sucrose 7. 20% Poloxamer 407 with 5% dextran 8. 20% Poloxamer 407 in 10 mM histidine pH 7 9. 20% Poloxamer 407 in 20 mM citrate buffer pH 6 10. 20% Poloxamer 407 in phosphate buffered saline pH 7 11. 20% Poloxamer 407 with 20% propylene glycol 12. 20% Poloxamer 407 with 10% polyethylene glycol 13. 20% Poloxamer 407 with 20 mM Tris buffer pH 7 14. 20% Poloxamer 407 with 3% isopropyl myristate 15. 20% Poloxamer 407 with 5% povidone 16. 20% Poloxamer 407 with 3% lactose 17. 20% Poloxamer 407 with 3% trehalose 18. 20% Poloxamer 407 with 0.5% human serum albumin 19. 20% Poloxamer 407 with 0.5% human serum albumin 900 ug NaCl 20. 20% Poloxamer 407 with 0.5% recombinant human serum albumin 21. 20% Poloxamer 407 with 0.5% gelatin 22. 20% Poloxamer 407 with 0.5% recombinant gelatin 23. 20% Poloxamer 407 with 0.5% hyaluronic acid 24. 20% Poloxamer 407 with 0.5% collagen 25. 20% Poloxamer 407 with 2% hydroxypropyl methylcellulose 26. 20% Poloxamer 407 with 2% lecithin
To determine that active botulinum toxin was released from each of the 26 thermo-reversible poloxamer formulations, light chain activity was measured using a fluorescent SNAP-25 substrate coupled with HPLC. Samples incubated with the substrate produce a cleavage product that is separated by RP-HPLC and detected via fluorescence. The amount of cleavage product is proportional to enzymatic activity.
Poloxamer 407 can be further manipulated pre and/or post-injection by applying heat or cold-packs to desired areas (injected and/or non-injected) achieve the desired effect. Additional ingredients can be added to the formulation to modify the attributes (causing increases/decreases in gelling temperatures, for example). Ingredients to alter osmolarity and pH (buffers) can be added. Administration can be topical rather than injectable; for example, in a transdermal delivery scheme, the formulation can contain permeation enhancers, and may be combined with a device such as a patch having additional permeation attributes, such as abrasives or microneedles, for example. Preservatives can also be included in the formulation. Colorants, such as pharmaceutically acceptable dyes, can be included to better visualize the material before and after application.
Example 2
Use of a Poloxamer-Botulinum Toxin Pharmaceutical Composition
A 48 year old male is diagnosed with a spastic muscle condition, such as cervical dystonia. Between about 50 to about 500 units of botulinum toxin type A (such as BOTOX®) combined with formulation 2 (20% Poloxamer 407 in 0.9% sodium chloride) in Example 1, and is administered by intramuscular injection. The formulation releases therapeutic amounts of the botulinum toxin over a 1 month period. Within 1-7 days the symptoms of the spastic muscle condition are alleviated and alleviation of the symptoms persists for at least about 6 months.
Example 3
Use of a Poloxamer-Botulinum Toxin Pharmaceutical Composition
A 22 year old female sees her physician to report and treat her uncontrollable and excessive armpit, sweating or as its known in the medical arts, axillary sweating. After gravimetric measurement of her sweat production, she is diagnosed as suffering from hyperhidrosis.
About 100 units of botulinum toxin type A (such as BOTOX®) is combined with formulation 12 (20% Poloxamer 407 with 10% polyethylene glycol) in Example 1, and is administered by intradermal injection into the axillary hyperhidrotic area (as determined by Minor's starch-iodine test). After injection, an ice pack is placed over the injected area, cooling the area and making the injected thermo-reversible poloxamer-botulinum toxin pharmaceutical composition less viscous, allowing the attending physician to massage the injected area, allowing a more even spread of the injected composition. Within 7 days, the excessive axial sweating is reduced and alleviation is observed for about 8 months.
Example 4
Use of a Poloxamer-Botulinum Toxin Pharmaceutical Composition
A 38 year old woman reports to her dermatologist that she can no longer withstand the sight of her glabellar lines (dynamic wrinkles between the brows caused by the contraction of corrugator and/or procerus muscles) and that they have become a source of great consternation. The dermatologist determines to treat her with a poloxamer-botulinum toxin pharmaceutical composition.
About 500 units of a botulinum toxin type B is combined with formulation 25 (20% Poloxamer 407 with 2% hydroxypropyl methylcellulose) in Example 1, and is administered by intramuscular injection directly into the corrugator and procerus muscles. Areas outside the desired treatment area are pre-heated (utilizing a heating pad to gradually warm the areas not injected, for example, from about 37 to about 43 degrees Centigrade, to elevate the temperature relative to the areas of injection) to prevent drug migration into those regions. Within about 7 days, the patient reports that the glabellar lines have been reduced and the skin between her brows is smoother. The alleviation of the wrinkles lasts for about 4 months.
Similarly, a botulinum toxin type A (BOTOX®) at about 2 units per 0.1 mL of added formulation can be injected at each of about 5 injection sites in corrugator and procerus muscles for a total dose of about 10 units per 0.5 mL of thermo-reversible poloxamer-botulinum toxin pharmaceutical composition. As an additional step, after or before injection into the muscles, a hot pad can be placed over the injection site to warm the area. Thus, if a hot pad is so placed, the injected poloxamer-botulinum toxin pharmaceutical composition can gel faster than if injected at just body temperature. The pad can be between about 37 degrees and about 43 degrees Centigrade, for example. The pad can be placed onto the area injected or to be injected and warmed up to between about 37 degrees and about 43 degrees Centigrade, for example.
Example 5
Use of a Poloxamer-Botulinum Toxin Pharmaceutical Composition
A 78 year old man is brought to his urologist, complaining of an inability to withhold his urine for any significant amount of time. The urologist determines that the patient is incontinent and has an overactive bladder (OAB) and that his detrusor muscle should be injected with a poloxamer-botulinum toxin pharmaceutical composition.
About 250 units of a botulinum toxin type A (BOTOX) is combined with formulation 2 (20% Poloxamer 407 in 0.9% sodium chloride) of Example 1 (about 250 units of toxin in about 10 mL of formulation 2). Utilizing a flexible cytoscope and standard bladder wall injection equipment (local anesthetic, lubricants, etc. . . . ), the urologist proceeds to inject the patient's bladder wall at 10 sites (25 units/site) along the lateral walls, sparing the trigone and dome. Within about 7 days, the patient reports that he is able to hold his urine for many hours at a time, and that his voiding volume per visit to the urinal has more than doubled. The patient reports relief from his incontinence for approximately 7 months.
A bladder wall can also be injected with any one of the formulations (1-26) in Example 1 containing other botulinum toxin types, such as from about 50 to about 15,000 units of a botulinum toxin type B, utilizing from about 5 mL to about 30 mL of the formulations in Example 1. The thermo-reversible poloxamer-botulinum toxin pharmaceutical composition is injected into the bladder wall in about 5 to about 50 injection sites, as determined by an attending physician, and can include or exclude the trigone, if desired.
Example 6
Use of a Poloxamer-Botulinum Toxin Pharmaceutical Composition
A 67 year old man suffers from chronic urinary retention due to enlargement of his prostate. Upon presentation to his physician it is determined that the patient undergo administration of poloxamer-botulinum toxin pharmaceutical composition to the prostate in order to alleviate his urinary retention and treat the benign prostatic hyperplasia. About 200 units of botulinum toxin type A (BOTOX) is combined with 4 mL of formulation 2 (20% Poloxamer 407 in 0.9% sodium chloride) in Example 1 for transperineal injection into the bilateral lobes of the prostate (100 units per lobe).
After about 7 days, the patient reports an improvement in voiding of urine. His physician notes that after this treatment the patient has a decrease in post voiding residual volume and bladder pressure. These beneficial effects last for about 6 months and the physician notes that the patient's prostate has decreased in size and reports no adverse effects. A botulinum toxin type B (such as MYOBLOC) can also be utilized, for example, from about 250 units to about 1000 units per injection site.
A pharmaceutical composition according to the invention disclosed herein has many advantages, including the following:
1. the pharmaceutical composition can be prepared free of any blood product, such as albumin and therefore free of any blood product infectious element such as a prion.
2. the pharmaceutical composition has stability and high % recovery of toxin potency comparable to or superior to that achieved with currently available pharmaceutical compositions.
3. reduced toxicity, as assessed by either intramuscular or intravenous administration.
4. reduced antigenicity.
Various publications, patents and/or references have been cited herein, the contents of which are herein incorporated by reference in their entireties.
Although the present invention has been described in detail with regard to certain preferred methods, other embodiments, versions, and modifications within the scope of the present invention are possible. For example, a wide variety of stabilizing polysaccharides and amino acids are within the scope of the present invention.
Accordingly, the spirit and scope of the following claims should not be limited to the descriptions of the preferred embodiments set forth above.
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A thermo-reversible thermoplastic pharmaceutical composition, comprising a botulinum toxin and a biocompatible poloxamer which provides thermoreversibility to the composition and additionally stabilizes the botulinum toxin, is described. The pharmaceutical composition can be administered to a patient as a liquid, and gels after administration into a sustained release drug delivery system from which the biologically active botulinum toxin is released over a multi-day period thereby localizing the drug as a depot and controlling release to enhance the therapeutic effect per dose.
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This application claims benefit of provisional application Ser. No. 60/024,503 filed Aug. 23, 1996.
FIELD OF THE INVENTION
This invention relates to the isolation and purification of taxanes from naturally occurring, Taxus species, and more particularly, to an improved method for isolating taxanes by using a preparative scale technique amenable to commercial production.
BACKGROUND OF THE INVENTION
For hundreds of years most drugs were highly impure mixtures of composition derived primarily from plant or animal origin. As recently as the 1920's most active ingredients were used in only partially purified forms. Since then, vastly improved tools and methods for the purification of chemical compounds have been developed enabling identification of compounds that produce beneficial effects. This field science has become known generally as Natural Products Chemistry.
The foundation of Natural Products Chemistry rests on extraction, isolation and purification strategies. As is well appreciated in the art, different isolation procedures oftentimes yield a different profile of chemical compounds. Seemingly minor changes to an isolation procedure such as changing a solvent, the ratio of solvent or even the type of filter paper can result in large changes in the type, amount and purity of chemical compounds obtained. One procure designed to yield large quantities of a crystalline compound, might inadvertently eliminate or inactivate an even more valuable compound in the first extraction step.
A family of compounds isolated from the very slow growing yew (genus Taxus, family Taxaceae), have gained notoriety since the discovery that Taxol was found to be an effective cancer chemotherapeutic agent and was approved by the FDA for treatment of ovarian carcinoma. Since the recognition of Taxol's anticancer activities, research efforts to isolate other compounds from trees of the Genus Taxus have intensified to find improved methods of purification, and synthetic procedures.
Today, the taxane family of terpenes are considered as an exceptionally promising group of cancer chemotherapeutic agents. At least 60 different compounds have been reported in the literature posessing a taxane nucleus (4,8,12,15,15-pentamethyltricyclo[9.3.1.0 3 .8 ] pentadecane). ##STR1##
Many taxane derivatives, including taxol, taxotere, and cephalomannine are highly cytotoxic and have been shown to be effective against leukemia, advanced breast and ovarian cancers in clinical trials (W. P. MacGuire et al., Annals of Internal Medicine, vol 111, pg. 273, 1989). They have also exhibited promising activity against a number of other tumor types in preliminary investigations. Taxanes are believed to exert their antiproliferative effect on taxane sensitive cells by inducing tubulin polymerization, thereby forming extremely stable and nonfunctional microtubules (Eric K. Roxinsky et al., Journal of the National Cancer Institute, Vol. 82:1247-1259, 1990).
A major problem with all of the clinical studies is the limited availability of taxanes. For example, the only available natural source for taxol to date are several species of a slow growing Yew (genus Taxus), wherein Taxol is only found in very low concentrations (less than 400 parts per million) in the bark of these trees. Furthermore the extraction is difficult, the process is expensive and the yield of taxol is low (Huang et al., J. Nat. Prod. 49 665 1986 reported a yield of 0.01% taxol from Taxus brevifolia bark).
The number of patents describing the isolation and purification of taxol and taxanes from Taxus bark is increasing.
The procedures currently known for isolating taxol are very difficult and low-yielding. For example, a yield of 0.01% was reported from a large scale isolation starting with at least 806 lbs of Taxus brevifolio bark (Huang et al., J. Nat. Prod., 49:665, 1986). The isolation of taxol was described by other workers: Miller et al., J Org. Chem., 46:1469, 1981; McLaughlin et al., J. Nat. Prod., 44:312, 1981; Kingston et al., J. Nat. Prod., 45:466, 1982, and Senih et al., J. Nat. Prod., 47:131, 1994, U.S. Pat. No. 5,407,674 and U.S. Pat. No. 5,380,916. The reported yields of taxol from various species of yew range from 50 mg/kg to 165 mg/kg (i.e., 0.005-0.017%).
Koppaka (U.S. Pat. No. 5,380,916) describes a method for isolating taxol and its analogues from a crude extract of Taxus brevifolia and Taxus floridana, charactized by treating the crude extract by reverse phase liquid chromatography on an adsorbant, and recovering a number of compounds in pure form by elution. However, reverse phase chromatographic separation of impure taxanes from plant materials is expensive because of the cost of the column materials. Generally reverse phase separation can be used on the crude extraction from bark of some of the Taxus species because of the relatively low concentration of pigments, lipids and waxes and high concentration of taxol; however, the needles tend to contain lesser amounts of taxol and significant amounts of impurities and thus reverse phase chromatography for separation of taxanes form early stages of purification is not practical.
EsSohly et al. (see U.S. Pat. No. 5,480,639), describe methods of obtaining taxanes, comprising extracting and purifying a number of taxanes from ornamental cultivars using a series of organic and aqueous solvents and normal phase chromatography.
Methods of synthesis for the taxane ring skeleton are difficult, producing compounds deficient in pharmacological activity and are currently more expensive than isolation from the plant material. Thus, despite low yields, it is likely that the Taxus plant will remain a predominant reliable supply source for clinical quantities of taxol and its related compounds for years to come.
Although the use of taxol is successful against a number of specific tumor types, it is not universally effective. Hence, there is an urgent need for novel compounds from the taxane family which are closely related to taxol in their chemical structures but with more potent chemotherapeutic activities. New isolation procedures will lead to the purification and identification of new compounds. Moreover, a need exists to simplify the current procedures to produce taxanes and reduce the cost of such production by using simplified extraction and chromatographic techniques.
Therefore, purification techniques which provide high yields of known taxanes and new taxanes are needed to provide greater quantities of these promising therapeutic agents. The present invention provides a purification technique which accomplishes these goals.
SUMMARY OF THE INVENTION
Due to the immediate requirement for high yields of known taxanes and additional novel taxanes, the current invention is concerned with the isolation and purification of taxanes.
Accordingly, it is an object of this invention to provide a consistent method directed towards isolating compounds from plant matter derived from the Taxus genus of plants.
It is a further object of this invention to provide a method for the isolation of taxanes from plant matter that is easier than existing methods.
It is also an object of this invention to provide a method for the isolation of taxanes from plant matter that is on a preparative scale.
It is a further object of this invention to provide a method for the isolation of taxanes that uses less chromatographic columns, and in particular, less HPLC than existing methods.
These and other objectives, as well as the nature, scope and utilization of this invention, will become readily apparent to those skilled in the art from following the description, the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a separation scheme for isolating taxanes from Taxus canadensis in accordance with this invention.
DETAILED DESCRIPTION OF INVENTION
The starting material for use in this invention is vegetal material, selected from a group of plants commonly referred to as taxads. The most suitable plants of this group are the species Taxus. Amongst the Taxus species, Taxus canadensis A the preferred source for use in the isolation and purification of the novel taxane claimed in this invention. Taxus canadensis is a small ramping bush abundant in Quebec, Canada which seems to differ from other yews in the content of its taxanes. 9-dihydro-13-acetylbaccatin III is found in concentrations 3-7 times greater than taxol (Zamir L. O. et al. Tetahedron Letters 33 5173 1992).
The method disclosed is effective when using the roots or bark of the Taxus bushes but, as previously discussed, we consider it prudent to use a source that is rapidly regenerated (such as the leaves i.e. needles) and therefore in abundant supply.
The present invention describes a method for the isolation of taxanes from Taxus canadensis. This method was used successfully for the isolation of taxanes present in the plant material.
One particular advantage of this technique is that 10-deacetyl-baccatin III and 9-dihydro-13-acetylbaccatin III (an abundant taxane specific to T. canadensis needles) can be isolated by simple recrystallisations and preparative reverse phase HPLC instead of many silica gel columns.
The present invention will now be illustrated, but is not limited to be limited, by the following examples.
EXAMPLE 1
Isolation of Taxanes from Taxus canadensis
The plant material was collected in Quebec. The needles were stored at 4° C. in sterilized sand and peat moss and were dried before grinding. The needles were extracted by adding methanol (0.6 L) and dichloromethane (5.4 L) to a 20 L glass container equipped with a mechanical stirrer. Stirring is adjusted to 1.0-1.5 rotations per second and the dried/ground needles of Taxus canadensis (1.5 kg) are added gradually over a period of 30 minutes. The mixture is stirred for one hour and another 0.5 kg of needles (total of 2.0 kg) is added over a period of 10 minutes. After stirring for 24 hours the mixture is filtered over a Whatman paper #1 using a buchner funnel and an erlenmeyer flask with a slight vacuum. The needles are returned to the glass container and 3.0 L of dichloromethane:methanol (9:1) are added. The mixture is stirred for 24 hours and filtered. This time the needles are washed with 1.0 L of dichloromethane:methanol (9:1). This second filtrate is added to the first.
Washing the Extract with Water: Water (0.5 L) is added to the combined filtrate and stirred vigorously for 15 minutes or later which time the aqueous phase is removed from the mixture. This washing procedure is repeated three more times. The organic phase is not immediately evaporated but is filtered directly over charcoal.
Filtration of the Extract over Charcoal: The charcoal filter is prepared as follows: Norit SA3 charcoal (0.5 kg: 100 mesh--Aldrich) is mixed with celite(0.5 kg: AC 2098T-Anachemia) and placed into a course scintered glass funnel. The charcoal-celite mixture is soaked with dichloromethane:methanol (9:1) and washed with an additional 1.0 L of that solvent. The extract is filtered on this bed of charcoal which is then washed with 1.5 L of dichloromethane:methanol (9:1). The mixture is evaporated under vacuum using a rotovap and the residue is left under high vacuum for one hour using a vacuum pump to remove all traces of methanol.
Precipitation: The residue is dissolved in 0.2 L of toluene and transferred to a 2.0 L erlenmeyer flask. The solution is magnetically stirred while petroleum ether 35"-60° (0.2 L) is added dropwise over a period of 25 minutes. To avoid the formation of large lumps of solid, it is essential to have a fast uninterrupted stirring during addition. At the end of this addition, the mixture is stirred for an additional 15 minutes and filtered in the usual manner (buchner funnel with Whatman paper). The solid is not left to dry but is rinsed with 70 mL of toluene:petroleum ether (1:1). The solid is then air dried for 15 minutes.
Isolation of A Major Taxane, 9-dihydro-13-acetylbaccatin III: The solid is transferred to a 200 mL erlenmeyer flask and dissolved in 100 mL of methanol. After one hour, crystals of 9-dihydro-13-acetlybaccatin III are observed and the mixture is left at -20° C. for 18 hours to favor crystallization. The solid is filtered in the usual manner and washed with 2×10 mL, of cold methanol. The filtrate and the washings are kept aside for the next step (Filtrate A). The solid is often contaminated with black particles of charcoal which probably passes through the scintered glass during the charcoal filtration. To eliminate these particles, dichloromethane (20 mL) is added to the solid which dissolves rapidly and the insoluble black particles are filtered. The filtrate is evaporated on a rotovap, dichloromethane (2.0 mL) is added to dissolve the residue followed by methanol (80 mL) to induce crystallization. The mixture is left at -20° C. for 18 hours and filtered. The filtrate and washings are combined with Filtrate A. The solid is washed with cold methanol (5×1 mL) and dried under vacuum for 2 hours affording 1.2 g of 9-dihydro-13-acetyl baccatin III as a white product.
Isolation of 10-deacetylbaccatin III: Filtrate A is evaporated on a rotovap and acetonitrile (25 mL) is added. 10-deacetylbaccatin III is left to crystallize at room temperature for 18 hours, filtered and washed with 10 mL of acetonitrile. The filtrate and washings are kept aside for the next step (Filtrate B). A mixture of dichloromethane:methanol (1:1, 2 mL) is added to the solid which dissolves completely and acetonitrile (80 mL) is added to induce crystallization. After 18 hours at room temperature, the solid is filtered and washed with 10 mL of acetonitrile. The filtrate and washings are combined with Filtrate B. The solid is dried under vacuum for two hours affording 0.2 g of 10-deacetylbaccatin III as a brownish, slightly impure solid.
Removal of Water Soluble and Petroleum-Ether Soluble Components: Filtrate B is evaporated and the residue (15.0 g) is dissolved in actonitrile:methanol (1:1, 12 mL) The solution is stirred while petroleum-ether (100 mL) is added over a period of 10 minutes followed by water (10 mL) over 5 minutes. More water (140 mL) is added more rapidly over 10 minutes with stirring. The mixture involving two liquid phases and an insoluble residue is left standing for 0.5 hour with occasional shaking. During that time the insoluble gum hardens. The liquid phases are decanted; water is added over the gum and decanted. Drying under vacuum afforded 12.4 grams of a brownish gum which contains taxol as the major component along with a series of minor taxanes and other products as shown by HPLC analysis.
Isolation of Taxanes with Reverse Phase HPLC: Taxanes in the brown solid are separated on a preparative HPLC using an ODS-2 reverse phase column (2.0×50 cm; Whatman) and a Waters Delta Prep 3000 instrument coupled to a model 481 variable wavelength detector at 227 nm. The products are eluted with a gradient over 140 minutes of acetonitrile:water (25:75) to 100% acetonitrile. At 55.5 min, a peak comprising 10 hydroxyacetylbaccatin VI, among other taxanes is collected.
Purification of Taxanes Through Silvated Derivatives: The collected fraction is evaporated and dissolved in dry DMF (1.0 mL). Imidazole (60 mg) is added followed by triethylsilylchloride (100 mL). The solution is stirred at room temperature for 24 hours and water (3 mL) is added followed by ethyl acetate (3.0 mL). The phases are separated and the aqueous phase is extracted with ethyl acetate (2×3 mL). The combined organic extracts are washed with water (3×3 mL) and dried over magnesium sulphate. The mixture is filtered and evaporated. The residue is chromatographed on the same preparative HPLC system eluting with a gradient over 50 minutes of acetonitrile:water (70:30) to 100% acetonitrile. Peaks are collected which consists Taxanes as their silyl derivatives. The solvent is evaporated and a solution of HCl 0.10 N in 95% ethanol is added (2.0 mL). After the solution was left standing for 48 hours it is evaporated and chromatographed on the preparative HPLC system, eluting with a gradient over 50 minutes of acetonitrile:water (25:75) to 100% acetonitrile.
Final Purification on Analytical HPLC: is performed using the analytical HPLC described above and eluting with water:acetonitrile (29:21).
It is to be understood that the examples described above are not meant to limit the scope of the present invention. It is expected that numerous variants will be obvious to the person skilled in the art to which the present invention pertains, without any departure from the spirit of the present invention. The appended claims, properly construed, form the only limitation upon the scope of the present invention.
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This invention relates to an improved method for isolating taxanes by using a preparative scale technique amenable to commercial production. This method provides high yields of known taxanes in addition to new taxanes.
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REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of my copending U.S. patent application Ser. No. 560,262, filed Mar. 19, 1975, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to improvements to production line installations for manufacturing articles in large or small series, and more particularly to the arrangement of the working stations and the devices and circuits supplying such stations and to a process for manufacturing articles on such a production line.
2. Description of the Prior Art
In large scale serial manufacture, conventional machining or assembly line installations are known which are formed by central transfer lines or conveyors on which the articles to be treated move successively in front of a series of working stations at each of which a worker performs an elementary treatment or assembly operation. The operations are performed either mechanically or manually. In the former case, their automation calls for heavy investments which are justified only by large scale serial production and obviates all versatility in their use. In the latter case, the repetitive nature of the jobs raises difficult human problems, inter alia in large scale serial manufacture at the numerous stations which have not yet been automated.
In all cases, production lines of this kind call for heavy investment in the supply means, such as the transfer conveyor systems and the means for equipping the numerous individual working stations. Moreover, manufacturing workshops having multiple and independent machines or individual working stations, such as are always used in unit or small scale serial production, require greater versatility to make such transfer systems economical, which versatility is normally accomplished only at the cost of greatly reduced productivity.
SUMMARY OF THE INVENTION
This invention combines the advantages of both manufacturing methods -- i.e., versatility and productivity -- without having the disadvantages of the conventional central transfer production lines as regards investment and working conditions.
According to the invention, the production line comprises a line of independent work handling elements which are guided, as a rule can be actuated manually, and each receive articles or assemblies of articles to be treated, the line being connected to a plurality of stations for the individual treatment of an article. Each of the stations comprise at least two short identical treatment lines supplied by parallel branches of guide rails or tracks and connected to a common evacuating or discharge conveyor line, each treatment line successively receiving a group of handling elements whose articles or groups of articles conveyed are treated simultaneously for a plurality of operations, directly on their handling elements.
The articles can be treated in a number of series of identical operations successively on each article in a treatment line, the number being limited to the number of articles in the treatment line, or simultaneously on each side of the line. Means for locking the handling elements on each treatment line can be provided to ensure that they are retained in position during the treatment of the articles.
The extra tools, materials, and parts or members which take up little space required for the treatment are advantageously disposed in a carriage movable along each treatment line. Preferably the carriage comprises a number of compartmented sectors pivoted around the vertical pivot and successively presenting themselves opposite the treatment zone, each sector containing the materials and tools needed for one or more successions of identical operations to be carried out on the treatment line. Each carriage preferably contains the materials and members required for at least one day of work.
The invention also relates to handling elements which are especially well adapted for use in a manufacturing production line according to the invention. The handling elements according to the invention each comprise means for supporting at least two articles to be treated disposed symmetrically on such elements, and an assembly having support means for two assemblies of members required for the treatment of the articles. The handling elements can advantageously pivot through 180° around their respective vertical axes, and the various operations can be performed successively on each row of articles or group of articles to be treated, from the same side of the line.
BRIEF DESCRIPTION OF THE DRAWINGS
A non-limitative embodiment of the invention, adapted to a typical case of production difficulties of the kind specified and consisting of an assembly line for engines rebuilt for standard interchange, comprising numerous types of different engines and highly irregular seasonal production requirements, will now be described with reference to the accompanying drawings, wherein:
FIG. 1 is a plan view diagrammatically illustrating an engine assembly line, the engines being assembled in groups of two rows of four engines and handled in groups of two engines by a pivoting conveying device;
FIG. 2 illustrates diagrammatically in elevation the assembly zone, with the devices for locking and pivoting of the four pivoting conveying devices on which assembly is performed, only one of such devices having the main members to be assembled, so as not to overload the drawings;
FIG. 3 is a detailed elevational view of a handling element of pivoting conveying elements; and
FIG. 4 is a fragmentary sectional view illustrating another feature of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows the production or assembly line as comprising a supply line 1 connected to a plurality of individual treatment stations, only one of which is shown diagrammatically. The individual treatment stations comprise two short treatment lines 2 connected to an evacuating line 3. Each treatment line 2 is adapted to receive a first group 4a of four handling elements 5 in the standby position, a second group 4b of four handling elements 5 in the assembly position, and a third group 4c of four handling elements 5 in the test and checking position. The handling elements 5, suitably suspended from an overhead track or guide rail, are each formed by a pivoting conveying device comprising means enabling two engines 6 (shown diagrammatically) to be assembled and supported thereon.
The assembly location for each of the treatment lines 2 -- i.e., the location opposite the group 4b of handling elements 5 -- has guide rails 7 disposed respectively outside the individual assembly station formed by the lines 2 for supporting and allowing the displacement of a moving carriage 8 comprising four compartmented sectors 9 which can receive extra parts or members which do not take up much space, such as cylinder head gaskets, distributing members, bolts, etc., and the materials and tools required for assembling the main members which are supported by the pivoting conveying devices 5 as will be gathered hereinafter.
In a preferred embodiment, the conveying devices 5 are supported for pivotal movement around their vertical axes 10 in such a manner that two operators A and B can each successively proceed to assemble the eight engines supported by the conveying devices 5 after they have been rotated through 180° around their respective axes. Moreover, the operator can displace the moving carriage 8 as he wishes so that at all times the extra members and tools required are available opposite each of the engines to be assembled. Clearly, it is also possible for two operators placed on each side of a single line 2 to assemble simultaneously two engines mounted on the same conveying device, in which case the conveying device need not be pivoted.
In the embodiment illustrated, the group assembly stations are followed by a test, checking and running in station for the assembled engines. To this end, each line 2 is adapted to receive in succession to the group 4b a third group 4c of four handling elements. In the preferred embodiment, the distance apart of the lines 2 is such as to enable a single operator C to carry out tests on 16 engines, eight of which come from each group 4b of one line 2. A test bench 8a is conveniently disposed between the two lines 2. A return conveyor path 2a is provided following the test station of each line 2 outside the lines 2 to enable an engine 6a whose tests were unsatisfactory to be touched up or repaired at an adjacent work area and returned to the line 2 upstream of the test area for retesting as necessary.
FIG. 2 shows how the four pivoting conveying devices 5 for the group of engines to be assembled are suspended from an overhead guide rail or track 11 connected to an overhead framework 12. Each conveying device 5 comprises an upper frame 13 having rollers 14 which can move on the guide rail 11. Resilient bumpers or shock absorbing means can be provided on the frames 13 which contact one another. The treatment line comprises for each of the conveying devices 5 a pneumatic locking device 15 connected to the overhead framework 12 and then adapted, as will be seen hereinafter, to lift the frame 13 to retain the conveying device 5 in position during assembly.
Each pivoting conveying device 5 comprises a vertical shaft 10 around which it can pivot, the device 5 being locked in position by a manual lever 16 cooperating with a sleeve 17 connected to the upper frame 13, the shaft 10 rotating inside the sleeve 17. Mounted on the shaft 10 are two stellate supports 18 for the casing of the engines 6 to be assembled and an assembly 19, comprising a vertical generally rectangular frame 20 having on each of its faces supporting rods 21 having fingers 22 for supporting various main components required for the assembly of the engine. The assembly 19 can also comprise supporting feet 23 or baskets 24 adapted to support particular members or parts required for the assembly.
FIG. 2 therefore shows one of the pivoting conveying devices having a supply of assembly members supported by the assembly 19, including an oil casing 25 for the engine, a pump 25a, distributor casing 26, cam shaft 27 jackets 28, rods and pistons 29, cylinder head 30, flywheel 31, crank 32 and the complete transmission and a set of bearings (not shown). These main members are advantageously so disposed that they must be removed in the order of assembly. For instance, the oil pump 25a cannot be withdrawn before the oil casing 25 which is placed in front of it on the assembly 19, the oil casing itself uncovering the rocker cover.
FIG. 3 shows in greater detail the pneumatic device for locking the pivoting conveying device in position. The device comprises two pneumatic jacks 33 whose rods 34 act on hook 35 mounted for pivotal movement around pivots 36 connected to the overhead framework 12. The latter comprises in its lower part U-shaped chocking irons 37. By acting on the jacks 33, therefore, the upper frame 13 of the pivoting conveying device can be so raised that two parallel sides of the frame 13 are inserted inside the U-irons 37, ensuring that the pivoting conveying device is retained in position.
Clearly, a jack can also be placed in each pivoting conveying device to act so as to raise it as before. In that case the pivoting conveying device can be rotated manually through 180° around its pivot 10, as described hereinbefore, to enable the engines to be assembled.
The stellate supports 18 are adapted to be rotated around their horizontal axis by means of a gear reducer 38 actuated by a shaft 39 driven by a pneumatic motor 40 to at the same time control the rotation of the supports 18 of the four pivoting conveying devices (FIG. 2). The casings of the engines 6 are thereby pivoted, thus enabling the members to be mounted on the four main faces of the casings. In this example, in which the treatment or assembly operations are essentially manual, the individual operations are completed at the assembly station by a certain number of pneumatic tools, such as wrenches, screwdrivers, etc., suspended from a monorail above the assembly zone.
In one advantageous embodiment, depicted in FIG. 4, the floor 41 of the workshop is formed, at the treatment location of the lines 2 substantially beneath the handling elements, with a gutter 42 containing metal tank 43 adapted to receive the oil, waste and all foreign bodies. A metal grating 44 covers the tank 43 at the level of the floor 41 and enables the operator to stand above the receiving tank 43. The grating 44 can move around a hinge 45 disposed on one of the sides of the gutter 42 while the receiving tank 43 can pivot through 180° around another hinge 41 placed on the opposite side of the gutter 42. The workshop can therefore be cleaned periodically, for example, once a week, the receiving tank 43 being tipped out of the gutter 42 to pour its contents onto the workshop floor 41.
Work is preferably performed by three persons at each individual treatment station, one (C) performing the tests and grinding or running-in groups of 16 engines, eight of which were assembled by that operator and eight by another. During this time, the two other operators (A) and (B) proceed successively to assemble two more groups of eight. The operator who has carried out the tests then changes with one of the assemblers, as (A) who, after testing 16 engines will change in turn with the other assembler (B). The assembly can also be performed by two, simultaneously on each side of the assembly line, two grinding-checking stations preferably being used in that case on each line.
The number of articles simultaneously treated, in this case assembled engines, must be determined according to "mental load" -- i.e., the memory and training of the operators, who are assisted in this by a suitable distribution of the members on the supporting assemblies and in the lateral distributing magazine, one member covering the accessibility of another to ensure that the former is assembled first.
The installations according to the invention are advantageous, as in the example described, in manual treatment operations, which are still the most numerous, and in which they can readily be adapted to working conditions more compatible with human nature. They are all the more applicable to most various automated or mechanical operation without involving the risk of stoppages for adjustments or damage, as in the case of the convential linear transfer production lines. An installation of this kind, which can be adapted for the most various types of manufacturing work such as, for instance, treatments, machining, assembly, demounting, etc., starting from complete, partial or zero automations, has many advantages.
The transfer operations ensuring the flow of movement of the articles to be treated are performed solely by the guided handling elements, carriages or pivoting conveying devices, which are as a rule manually operated, economically constructed in large series and can readily be adapted to the various kinds of articles to be treated. All demounting and handling of the articles on their own is therefore eliminated. The treatment operations, adaptable production rate, in dependence on the number of lines put in operation, and the stoppage of one line due to damage or absenteeism, has no effect on the other lines. Similarly, the risks of misassembly of material or human origin are divided by the number of lines in operation.
Lastely, this type of installation affords the productivity advantages of continuous transfer lines, since the assembly, demounting and resumption times are eliminated, the handling times are reduced as far as possible, and the handling means according to the invention take the place of storage means. However, the invention obviates the disadvantages of a high investment cost, lack of flexibility and undeniable monotony as regards manual operations. Nevertheless, the elementary operations are carried out in repetitve series, allowing a rapid rate of production on a limited number of members in each treatment line.
Paradoxically, therefore, in contrast with the conventional manufacturing chain installations, the result is greatly reduced investment and less space occupied on the floor, and clearly superior productivity with a reduction of rejects and improvement in quality, while at the same time the installation according to the invention can readily be adapted to fluctuations in production programs, with normal working time tables, time tables according to teams, or even flexible time tables. The invention increases the responsibility of each operator for each article assembled and tested by him, and thus gives value to his work.
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Articles are manufactured on a production line including a plurality of independent work supporting and handling elements supported for movement along a conveying line connected to a plurality of stations for the individual treatment of an article. Each station includes at least two short treatment lines supplied with the handling elements by parallel branches of the conveying line, with the branches each being connected to a common discharge conveyor line, whereby each treatment line may receive a group of handling elements with the articles conveyed thereon receiving a plurality of operations at the stations while the articles are supported on the handling elements, with the group being moved from the branch lines after treatment of the entire group is completed.
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BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to a light emitting diode (LED) unit and, more particularly, to an LED unit having a lens which can produce an effectively converged light beam.
[0003] 2. Description of Related Art
[0004] LEDs, available since the early 1960's and because of their high light-emitting efficiency, have been increasingly used in a variety of occasions, such as residential, traffic, commercial, and industrial occasions. Conventionally, light directly output from the LED does not have a desirable pattern; therefore, a light-adjusting element, such as a lens, is used with the LED to modulate the light pattern thereof. However, a typical lens generally has a limited light-converging capability; that is, the light passing through the lens cannot be effectively converged to have a small light-emergent angle. Thus, the light pattern output from the lens may have a yellow annulus or shining annulus appearing at a periphery thereof, adversely affecting illumination effect of the lens.
[0005] What is needed, therefore, is an LED unit which can overcome the limitations described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0007] FIG. 1 is an isometric view of an LED unit of the disclosure.
[0008] FIG. 2 is an inverted view of a lens of the LED unit of FIG. 1 .
[0009] FIG. 3 shows a cross-section of the LED unit of FIG. 1 , with a printed circuit board on which the LED unit is mounted.
[0010] FIG. 4 shows a curve of curvatures of a first light-emergent face of the lens of FIG. 1 at different points along a top-to-bottom direction of the lens.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0011] Referring to FIGS. 1-3 , an LED unit of the present disclosure is illustrated.
[0012] The LED unit comprises an LED 10 and a lens 20 mounted on the LED 10 . The LED 10 comprises a heat-conducting base 12 , an LED die 14 mounted on a top of the base 12 , and an encapsulant 16 covering the LED die 14 and fixed on the top of the base 12 . The base 12 of the LED 10 is soldered on a printed circuit board 100 to conduct heat generated by the LED die 14 to the printed circuit board 100 . In addition, the LED die 14 is electrically connected with the printed circuit board 100 via the base 12 . The LED die 14 may be an InGaN chip, an InGaAs chip, a GaP chip or other suitable chips which could generate visible light with a desirable color. The encapsulant 16 is made of epoxy, silicon, glass or other transparent materials which have good light-permeable and water-proof capabilities. Phosphor may be doped within the encapsulant 16 to adjust the color of the light emitted from the LED die 14 . The encapsulant 16 is shaped like a dome so as to collimate the light from the LED die 14 into a converged beam. The LED 10 has an optical axis I, around which the light emitted from the encapsulant 16 is symmetrical in a surrounding space.
[0013] The lens 20 is made of transparent materials such as PC (polycarbonate) or PMMA (polymethyl methacrylate). The lens 20 comprises an optical member 22 , two opposite substrates 24 extending downwardly from a bottom face of the optical member 22 for supporting the optical member 22 , and a flange 26 extending outwardly from a circumference of a top of the optical member 22 , for being pressed by a clip (not shown) against the printed circuit board 100 to thereby secure the lens 20 on the printed circuit board 100 . A cavity 220 is defined in an interior of the lens 20 , recessed upwardly from a bottom thereof. The cavity 220 defines an opening (not labeled) at the bottom face of the optical member 22 . When the lens 20 is assembled to the LED 10 , the LED die 14 and the encapsulant 16 are received in the cavity 220 , and the base 12 is sandwiched between the two substrates 24 . The cavity 220 has a shape like a round column. An inner face of the lens 20 facing the encapsulant 16 of the LED 10 functions as a first light-incident face 2201 of the lens 20 to receive the light emitted from the LED 10 with a small light-emergent angle (such as light A shown in FIG. 3 ). Another inner surface of the lens 20 surrounding the encapsulant 16 of the LED 10 functions as a second light-incident face 2202 of the lens 20 to receive the light emitted from the LED 10 with a large light-emergent angle (such as light B shown in FIG. 3 ). The first light-incident face 2201 is curved and slightly protrudes downwardly towards the LED 10 , and the second light-incident face 2202 is a circumferential face of a column. In the embodiment of this disclosure, the first light-incident face 2201 is a spherical surface and has a curvature of 0.04 mm −1 . The first light-incident face 2201 and the second light-incident face 2202 cooperatively form a light-incident face 200 to refract all of the light of the LED 10 into the lens 20 .
[0014] The optical member 22 has an upwardly-expanding bowl shape. An outer circumference of the optical member 22 functions as a light-reflecting face 300 of the lens 20 to totally reflect the light transferred from the second light-incident face 2202 towards the top of the lens 20 . Alternatively, the light-reflecting face 300 can be further coated with a reflective layer (such as aluminum layer or silver layer) for promoting light reflection. The flange 26 is extended along the light-reflecting face 300 . The light-reflecting face 300 is divided by the flange 26 into a first light-reflecting face 2203 and a second light-reflecting face 2204 . The first light-reflecting face 2203 is conical and expands from the bottom towards the top of the lens 20 . The second light-reflecting face 2204 is vertical.
[0015] The optical member 22 has a top face which is planar and circular. A center of the top face of the optical member 22 is concaved downwardly to form a columnar recessed portion 224 . The recessed portion 224 is rotationally symmetrical relative to the optical axis I of the LED 10 . The top face of the optical member 22 directly connects with the second light-reflecting face 2204 . A protrusion 228 is protruded upwardly from a central area of a bottom face of the recessed portion 224 . The protrusion 228 is shaped like a dome and has a continuously curved top face. The protrusion 228 is also rotationally symmetrical relative to the optical axis I of the LED 10 . The curved top face of the protrusion 228 is located just opposite to the first light-incident face 2201 . The curved top face of the protrusion 228 acts as a first light-emergent face 2205 and takes charge mainly for the light transmitted from the first light-incident face 2201 . The top face of the optical member 22 of the lens 20 acts as a second light-emergent face 2206 and takes charge mainly for the light totally reflected by the light-reflecting face 2203 . The curved top face of the protrusion 228 and the top face of the optical member 22 refract nearly all of the light from the LED 10 out of the lens 20 within a small light-emergent angle. In other words, the first light-emergent face 2205 and the second light-emergent face 2206 of the lens 20 cooperatively form a light-emergent face 400 to refract the light within the lens 20 towards a place above the lens 20 .
[0016] Referring to FIG. 4 also, a length of the first light-emergent face 2205 from a top to a bottom thereof is supposed to be 1L. The first light-emergent face 2205 has a curvature firstly increasing gradually from a top (i.e., first position) towards a bottom of the first light-emergent face 2205 of the protrusion 228 ; at a second position which is located away from the top of the first light-emergent face 2205 for about 45% of the length (0.45L), the curvature starts to decrease gradually; at a third position which is located away from the top of the first light-emergent face 2205 for about 70% of the length (0.7L), the curvature starts to increase gradually again; finally, at a fourth position which is located away from the top of the first light-emergent face 2205 for about 95% of the length (0.95L), the curvature starts to decrease gradually again, within a small range till a bottom (fifth position) of the first light-emergent face 2205 of the protrusion 228 , which is away from the top of the first light-emergent face for 100% of the length (1L). In the embodiment of this disclosure, the first light-emergent face 2205 has a curvature of 0.0083 mm −1 at the first position (the origin of the coordinate of FIG. 4 ), a first curvature of 0.182 mm −1 at the second position (0.45L), a second curvature of 0.066 mm −1 at the third position (0.7L), a third curvature of 0.1964 mm −1 at the fourth position (0.95L) and a curvature of 0.1923 mm −1 at the fifth position (1L). The abscissa of the coordinate of FIG. 4 represents the length of the first light-emergent face 2205 of the protrusion 228 measured from the top to the bottom of the first-emergent face 2205 . The ordinate thereof represents the curvatures of the first light-emergent face 2205 of the protrusion 228 along different points thereof.
[0017] Being adjusted by the first and second light-incident faces 2201 , 2202 , the first and second light-reflecting faces 2203 , 2204 , and the first and second light-emergent faces 2205 , 2206 , the light emitted from the LED 10 could be effectively converged within a small angle, thereby preventing a periphery of a light pattern output by the LED 10 via the lens 20 from being yellow or shining.
[0018] It is believed that the present disclosure and its advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the present disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments.
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An LED unit includes an LED and a lens mounted on the LED. The lens includes a light-incident face adjacent to the LED, a light-emergent face remote from the LED, and a light-reflecting face between the light-incident face and the light-emergent face. The light-incident face includes a first light-incident face faces the LED, and the light-emergent face having includes a first light-emergent face located opposite to the first light-incident face. The first light-emergent face is a continuously curved face which has a curvature, along a top-to-bottom direction of the lens, firstly increasing gradually, then decreasing gradually and then increasing gradually again.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a system in which charge air for an automotive engine is compressed and cooled by the same rotating machine.
[0003] 2. Disclosure Information
[0004] Automotive history is replete with designs for charge boosting of reciprocating combustion engines. A veritable plethora of systems have been used, including turbochargers, superchargers, and other such devices. A common problem associated with turbocharging and supercharging is the necessity of removing heat from the compressed air charge. Heat should be reduced from the charge for a couple of reasons, such as increasing density of the air charge, and helping to prevent knock. Unfortunately, the need for charge air heat extraction, which is commonly called intercooling, greatly increases the complexity of the charge air system because the charge air flowing from the turbocharger, supercharger or other device, must pass through a heat exchanger, which of course must be supplied not only with the charge air but also with a cooling fluid, whether it be ambient air or some other fluid. Accordingly, it has not generally been possible to close couple superchargers to engines very readily in any package efficient manner, given the necessity or at least the desirability, to use charge air intercooling.
[0005] A system according to the present invention solves the problems associated with prior boosting and charge air cooling systems by combining these functions into a single rotating machine. As will be explained in further detail below, the charge compression machine may comprise either a turbocharger or a supercharger, but in any event, the present machine uses refrigeration actually incorporated within the compression machine or booster to accomplish charge air cooling, thereby producing a very lightweight, compact, energy efficient, and powerful engine assist device.
SUMMARY OF THE INVENTION
[0006] An engine having a charge air conditioning system comprising a charge air booster, a refrigerant-to-air heat exchanger integral with the charge air booster, and a refrigeration system for supplying refrigerant to the refrigerant-to-air heat exchanger.
[0007] A charge air booster according to the present invention may comprise a supercharger driven by the engine directly and mechanically, or a turbocharger driven by exhaust gas from the engine, or a supercharger driven indirectly by an electric motor or hydraulically. In any event the refrigerant is preferably furnished to the heat exchanger as a liquid. The liquid may comprise either a liquid which does not change state in its course through the refrigerant-to-air heat exchanger, or a more traditional refrigerant which does change state from a liquid to a gas on its course through the refrigerant-to-air heat exchanger. In the latter case, the heat exchanger may comprise an evaporator which is mounted within the charge air booster, and with the refrigeration system providing liquid refrigerant to the evaporator, so that at least some of the refrigerant changes to a gas while the refrigerant is flowing through the evaporator so as to extract heat from air flowing through the charge booster. In the event that the booster comprises a centrifugal compressor, the evaporator may be mounted within a cover section of the compressor. As such, the evaporator may comprise an annular flow passage having an inlet for liquid refrigerant, an outlet for vaporized refrigerant, and an inner wall comprising a portion of the cover of the compressor. In the event that a liquid is used for the refrigerant, the annular flow passage feature may be retained. The flow passage will incorporate an inlet and outlet for liquid.
[0008] If a refrigeration system using a change of phase refrigerant is used as part of the current system, the refrigeration system may be used to provide refrigerant not only to the intercooler but also to an evaporator comprising a portion of a passenger cabin climate control system. In this case, the refrigerant system will of course be powered by the engine of the vehicle.
[0009] A charge air conditioning system with intercooling according to the present invention may be applied to a V-type engine. The supercharger and inner cooler may thus have outlets for providing chilled and compressed air to both banks of a V-type engine.
[0010] A method of providing compressed and thermally densified air charge to an engine includes the steps of filtering an air stream flowing into an engine, measuring the mass of air flowing into the engine, simultaneously compressing and extracting heat from the air charge, and conducting the compressed and thermally densified air to the engine.
[0011] It is an advantage of the present invention that air may both be compressed and chilled in a single machine taking up less space, weighing less and using less energy than prior art systems for compressing and intercooling charge air furnished to an engine.
[0012] It is a further advantage of the present invention that the present system will reduce costs associated with charge air compressing and intercooling.
[0013] Other advantages, as well as objects of the present invention will become apparent to the reader of this specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a schematic representation of an engine having a charge air boosting and intercooling system according to the present invention.
[0015] [0015]FIG. 2 is a partially schematic representation of a charge air boosting and intercooling device according to one aspect of the present invention.
[0016] [0016]FIG. 3 is an example of a mechanically driven device according to the present invention taken along the line A-A of FIG. 2.
[0017] [0017]FIG. 4 is an example of a turbocharger device according to the present invention taken along the line A-A of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] As shown in FIG. 1, booster 10 is applied to engine 12 . The engine receives air from air filter 14 which flows through airflow sensor 16 into booster device 10 . Air is compressed and then chilled or intercooled within booster device 10 before it flows through discharge pipe 34 and into plenum 18 and then through air distribution pipes 20 into engine 12 . The flow of the air into the engine is partially controlled by throttle 22 . Booster 10 has the capability of not only compressing, but also intercooling air furnished to engine 12 because booster 10 is furnished with refrigerant which flows through a control device 58 having gone through and being condensed by condenser 26 following compression by compressor 24 . Control device 30 controls the flow to air conditioning evaporator core 32 , which is used to provide cooling for the cabin air of the automotive vehicle.
[0019] As noted above, a system for providing refrigerant to booster 10 could also comprise a circulating liquid with condenser 26 being replaced with a tank which merely contains a liquid cooled by ambient air or other means. Such details are left to those skilled in the art and wishing to apply a system according to the present invention.
[0020] [0020]FIG. 2 illustrates a charge air booster and intercooling device according to the present invention in which air entering inlet 38 is picked up by impeller 36 and compressed and sent to outlet 40 into discharge pipe 34 . According to the present invention, while the air is being compressed, it is simultaneously chilled because refrigerant circulates into inlet 44 in through a plurality of passages or channels in the outer wall of cover 41 and having circulated through channels 42 , leaves the unit at outlet 46 .
[0021] [0021]FIG. 3 illustrates greater detail of channels 42 and 43 . It is noted that channels 42 are formed in cover section 41 , whereas channels 43 are formed in cap plate 39 . Those skilled in the art will appreciate in view of this disclosure that other types of refrigerant conducting channels and internal fin arrangements may be used with a charge air cooler and compressor according to the present invention.
[0022] The device of FIG. 3 has a pulley 48 to illustrate a belt drive from the engine's crankshaft or other rotating shaft of engine 12 . Those skilled in the art will appreciate in view of this disclosure, however, that other types of drives, such as gear drive or chain drive, hydraulic drive, electric motor drive, or other types of drives could be used with the device of FIG. 3.
[0023] [0023]FIG. 4 illustrates a device in which impeller 36 is driven by a turbo device 52 having a turbine according to conventional usage, with the turbine having exhaust inlet 54 and outlet 56 . The illustrated refrigerant channels 42 and 43 are similar to those illustrated in FIG. 3.
[0024] While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
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A charge air conditioning system, including a charge air booster, a refrigerant-to-air intercooler which is integral with the charge air booster, and a refrigeration system for supplying refrigerant to the refrigerant-to-air intercooler.
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The invention is directed to a collector having an externally disposed nonimaging reflector and more particularly is directed to a solar collector with a heat pipe positioned within an evacuated glass tube with an externally disposed nonimaging reflector.
BACKGROUND OF THE INVENTION
It was recognized more than 20 years ago, that combining selective absorbers, vacuum insulation and nonimaging concentration (using Compound Parabolic Concentrator, or “CPC”, type optics as shown in FIG. 9A-9C ) enabled stationary mid-temperature collectors to have a useful operating range approaching 300 degrees Celsius”. Following the early proof-of-concept experiments, a commercial collector was developed in the last 5-years with good performance up to 250 degrees Celsius. These configurations integrated all the optics within the vacuum envelope. For this reason we refer to them as ICPC's (integrated CPC's). Their cost of manufacture is presently too high for widespread applications. On the other hand, the advent of very low-cost evacuated tubes allows us now to consider these as candidates for low-cost mid-temperature applications. One can combine various of these features to use such low-cost tubes (intended as stand-alone low-temperature collectors for providing domestic hot water) as receivers and now combined with external nonimaging reflectors. Since these glass tubes were originally intended for low-temperature (domestic hot water) use, their use at higher temperatures raised issues such as providing for efficient heat transfer to a working fluid, and assuring against thermal-induced tube breakage.
A solar collector which is efficient at temperatures in the 125 to 150 degree Celsius above ambient range would therefore be of great utility for many high-value applications. For example, operating temperatures for solar cooling in conjunction with double-effect chillers are in this range. At the same time the collector component would need to be low-cost, have minimal operation and maintenance cost and long life. The external reflector form of a CPC has the potential for satisfying these criteria. The vacuum receiver has intrinsically long-life, being protected from the environment. The impressive commercial development of vacuum solar collectors in China over the last decade and more demonstrates that these can be manufactured and sold at low-cost. To give an example; in the year 2000 the all-glass dewar type solar tube made in China was available at an OEM cost of $3 US. Since the volume of manufacturing has been rising, prices are not increasing. It is significant to observe that a wide-angle CPC reflector will “unwrap” the cylindrical solar tube to an aperture of approximately 0.2 square meters. Therefore the vacuum component contributes $15 per square meter to the cost. The heat extraction device which may be a manifold likely adds a similar amount. The nonimaging reflector can be estimated at $20 per square meter, which is dominated by the material cost for a high quality aluminum mirror. An installed cost of approximately $100 per square meter would be a reasonable goal. The availability of an efficient mid-temperature solar collector for $100 per square meter would have a broad vista of applications.
SUMMARY OF THE INVENTION
A solar collector system is directed to a combination of a heat pipe disposed within a housing which is at least partially transparent to light with the housing preferably evacuated. The heat pipe includes a copper pipe and coupled aluminum heat transfer fins disposed about the heat pipe. The fins are molded to optimize thermal contact with the heat pipe and interior surface of the housing. The solar collector further includes a reflector assembly externally disposed to the housing to simplify construction and costs of manufacture. Preferably the reflector is a nonimaging design.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows XCPC thermal model performance and measured performance of a test panel with dewar tubes;
FIG. 2 shows instantaneous solar to thermal conversion efficiency for a heat pipe embodiment for mid temperature performance ranges;
FIG. 3 shows performance limits of a commercial VAC 2000 solar collector;
FIG. 4A shows a disassembled embodiment of a portion of a solar receiver and FIG. 4B shows a cross section of an assembled unit;
FIG. 5 shows a partially assembled collector system with the manifold and heat pipe in position;
FIG. 6 shows a first collector configuration with external reflector;
FIG. 7 shows a second collector configuration with external reflector;
FIG. 8 shows a third collector configuration with external reflector;
FIG. 9A shows a CPC shape for various incidence angles, FIG. 9B shows 0° (normal) incidence and FIG. 9C SHOWS 30° incidence;
FIG. 10A shows a plot of thermal performance of collector test number C444 with wind; FIG. 10B shows the performance without wind;
FIG. 11A shows a plot of thermal performance of collector test number C500 with wind; FIG. 11B shows the performance without wind; and
FIG. 12A shows a plot of thermal performance of collector test number C370 with wind; FIG. 12B shows the performance without wind.
DESCRIPTION OF PREFERRED EMBODIMENTS
In accordance with the invention, two types of preferred combination of solar collectors 12 (concentrators or receivers) are described, including an all glass dewar-type tube 11 and a heat-pipe 10 in a conventional evacuated tube 13 (see FIGS. 4A , 4 B and 5 ). The dewar-type 11 is very low-cost since it is made in large quantities by a large number of manufacturers and uses a very low-cost borosilicate glass tubing. Good heat transfer poses technical challenges, and our experiments with a heat transfer compound to couple the tube 11 to a manifold 20 gave encouraging results. The preliminary mid-temperature performance obtained with a test panel with dewar tubes is compared with that predicted by a simple model shown in FIG. 1 . The heat-pipe evacuated tube 13 (see FIG. 4B ), uses the same very low-cost glass tubing. The heat transfer is accomplished in an elegant way by the incorporation of the heat pipe 10 within the evacuated tube 13 which in turn is disposed in a full panel array 15 (see FIGS. 4A , 4 B and 5 ). The heat pipe 10 of FIGS. 4A and 4B includes a copper heat pipe 16 and contoured aluminum heat transfer fins 18 with the heat pipe 10 inserted into the glass tube 14 sandwiched between two aluminum fins 18 . The fins 18 are molded to maximize contact with the heat pipe 10 and the inside surface of the evacuated glass tube 14 . The heat pipe 10 transfers heat to the manifold 20 shown in FIG. 5 via heat transfer liquid inside the hollow heat pipe 10 . The hollow centre of the heat pipe 10 includes a vacuum, so that at even at temperatures of around 25-30° C. the well known heat transfer compound will vaporize. When heated the vapor rises to the tip (condenser) of the heat pipe 10 where the heat is transferred to the water flowing through the manifold 20 . The loss of heat causes the vapor to condense and flow back down the heat pipe 10 where the process is once again repeated. The preliminary mid-temperature performance obtained with the prototype heat-pipe version is shown in FIG. 2 . The performance limit of known CPC-type vacuum solar collectors (not shown) can be gauged from FIG. 3 . In this type of solar device both absorber and nonimaging concentrating optics are encased in an integral glass envelope, and this is called the integrated CPC or I CPC. Commercial collectors of this type have a higher cost than the all glass dewar type with external CPC reflectors 22 of FIGS. 6-8 . However, it does indicate a practical and realizable performance upper limit for the stationary nonimaging solar collectors 12 . One can further combine the advantages of the low-cost all-glass evacuated receiver with the heat pipe. As shown in FIGS. 4A , 4 B and 5 , the heat pipe 10 and absorber fin assembly is inserted in the double-walled evacuated tube 14 and the heat pipes 10 are inserted into the simple flow-through heat exchanger manifold 20 . There is no fluid connection which is one of the chief advantages of a heat application, but appears sufficiently robust to withstand stagnation temperatures. Various examples of performance of a conventional evacuated tube but externally disposed reflector (without the heat pipe 10 ) are shown in Examples I-III wherein collector test results are shown in FIGS. 6-8 for the collector configurations. These tests were made by Solartechnik Prüfung Forschung, located in Bern, Switzerland.
While preferred embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with one of ordinary skill in the art without departing from the invention in its broader aspects.
EXAMPLES
The following non-limiting examples describe various embodiments and associated performance test results.
Example I
Collector Test No. C444. The embodiment of FIG. 6 is described in Table 1 and was subjected to various tests as set forth in Table 2. Note there was no stagnation temperature for standard values ISO 9806-2 and EN 12975-2 are 30° C./1000 W/m 2 . The thermal performance (flowrate at test: 204 l/h) is shown in FIGS. 10A and 10B , with and without wind, respectively.
TABLE 1
Contact
Ritter Solar GmbH, D-72135 Dettenhausen
Tel. +49 (07157) 5359-0,
Fax +49 (07157) 5359-20
Distributed in*
DE
Type
ETC, cylindrical absorbers, CPC,
direct heat transfer
Assembly
Installation*
Installation on sloping roof,
Flat roof with support
Rated flowrate*
180 l/h
Absorber coating*
Al/Al N
Dimensions
2.010 m 2 , 1.988 m 2 , 2286 m 2
(absorber, aperture, gross)
Gross dimensions:
1.640 × 1.394 × 0.105
l, w, h (in m)
Weight including glazing*
35 kg
*= manufacturer information
TABLE 2
Carried
Test
out
Section
Report*
Durability test according to ISO
No
3
LTS C444
Durability test according to EN
No
3
C444LPEN
Measurement of stagnation temperature
No
3.1
Efficiency measurement acc. SPF
Yes
4.1
Efficiency measurement acc
Yes
4.1
ISO, DIN, EN
Incidence angle modifier (IAM)
Yes
4.4
Measurement of pressure drop
No
4.5
Measurement of thermal capacity
Yes
4.6
Measurement of time constant
Yes
4.6
*= contact manufacturer for details!
Tables 3A and 3B illustrate characteristic efficiency values (normal incidence, G=800 W/m 2 ) for efficiency with and without wind, respectively. Tables 4A and 4B show power output (power in watts per collector, normal incidence, beam irradiation) with and without wind, respectively.
TABLES 3A and 3B
Reference area
Absorber
Aperture
Gross
Reference area
Absorber
Aperture
Gross
η (T* m = 0.00)
0.62
0.62
0.54
η (x = 0.00)
0.62
0.62
0.54
η (T* m = 0.05)
0.56
0.57
0.49
η (x = 0.05)
0.56
0.57
0.50
η (T* m = 0.10)
0.50
0.51
0.44
η (x = 0.10)
0.50
0.51
0.44
TABLES 4A and 4B
Irradiation
400 W/m 2
700 W/m 2
1000 W/m 2
Irradiation
400 W/m 2
700 W/m 2
1000 W/m 2
t m − t e = 10K
474
846
1′218
t m − t e = 10K
475
847
1′219
t m − t e = 30K
429
801
1′173
t m − t e = 30K
431
803
1′175
t m − t e = 50K
382
754
1′126
t m − t e = 50K
385
757
1′129
Table 5 shows incidence angle modifier (IAM), Table 6 shows pressure drop in Pascals (test fluid 33.3% Ethylenglykol) and Table 7 shows thermal capacity and time constant.
TABLE 5
0°
10°
20°
30°
40°
50°
60°
70°
80°
90°
K(Θ), long
1.0
0.90
0.0
K(Θ), trans
1.0
1.01
1.0
1.01
1.01
1.05
1.16
0.0
TABLE 6
100 l/h
150 l/h
250 l/h
350 l/h
500 l/h
20° C.
60° C.
80° C.
TABLE 7
Thermal capacity (kJ/K)
Time constant (s)
16.2
202
These tests were performed by SPF, Hochschule Rapperswil (HSR) at Oberseestr. 10, CH-8640 Rapperswil.
Example II
Collector Test No. C500. (Consolar GmbH, TUBO 11 CPC) The embodiment of FIG. 7 is described in Table 8 and the tests of Table 9 were performed. There was no stagnation temperature for standard values ISO 9806-2 and EN-12975-2 were 30° C./1000 W/m 2 . The thermal performance (flowrate at test: 100 l/h) is illustrated in FIGS. 11A and 11B , with and without wind, respectively.
TABLE 8
Contact
Consolar GmbH, D-60489 Frankfurt/M.
Tel. +49 (069) 61 99 11 30,
Fax +49 (069) 61 99 11 28
Distributed in*
DE, AT, *EU*
Type
ETC, cylindrical absorbers, CPC,
direct heat transfer
Assembly
Installation*
Installation on sloping roof,
Flat roof with support
Rated flowrate*
100 l/h
Absorber coating*
Metal carbide
Dimensions
0.873 m 2 , 0.967 m 2 , 1.163 m 2
(absorber, aperture, gross)
Gross dimensions:
1.860 × 0.625 × 0.045
l, w, h (in m)
Weight including glazing*
13 kg
*= manufacturer information
TABLE 9
Carried
Test
out
Section
Report*
Durability test according to ISO
No
3
LTS C500
Durability test according to EN
No
3
C500LPEN
Measurement of stagnation temperature
No
3.1
Efficiency measurement acc. SPF
Yes
4.1
Efficiency measurement acc
Yes
4.1
ISO, DIN, EN
Incidence angle modifier (IAM)
Yes
4.4
Measurement of pressure drop
Yes
4.5
Measurement of thermal capacity
No
4.6
Measurement of time constant
No
4.6
*= contact manufacturer for details!
Tables 10A and 10B illustrate characteristic efficiency values (normal incidence, G=800 W/m 2 ) for efficiency with and without wind, respectively. Tables 11A and 11B show power output (power in watts per collector, normal incidence, beam irradiation) with and without wind, respectively.
TABLES 10A and 10B
Reference area
Absorber
Aperture
Gross
Reference area
Absorber
Aperture
Gross
η (T* m = 0.00)
0.73
0.66
0.55
η (x = 0.00)
0.73
0.66
0.55
η (T* m = 0.05)
0.66
0.59
0.49
η (x = 0.05)
0.67
0.60
0.50
η (T* m = 0.10)
0.59
0.53
0.44
η (x = 0.10)
0.61
0.55
0.46
TABLES 11A and 11B
400
700
1000
400
700
1000
Irradiation
W/m 2
W/m 2
W/m 2
Irradiation
W/m 2
W/m 2
W/m 2
t m − t e = 10K
241
431
622
t m − t e = 10K
244
434
624
t m − t e = 30K
217
407
597
t m − t e = 30K
224
414
604
t m − t e = 50K
192
383
573
t m − t e = 50K
204
394
584
Table 12 shows incidence angle modifier (IAM), and Table 13 shows pressure drop in Pascals (test fluid 33.3% Ethylenglykol).
TABLE 12
0°
10°
20°
30°
40°
50°
60°
70°
80°
90°
K(Θ), long
1.0
0.93
0.0
K(Θ), trans
1.0
1.0
1.0
0.95
0.82
0.84
0.90
1.02
1.03
0.0
TABLE 13
50 l/h
100 l/h
150 l/h
175 l/h
200 l/h
20° C.
6400
13300
21400
26000
30700
60° C.
80° C.
Example III
Collector Test No. C370. (Paradigma-Schweiz, CPC 14 Star) The embodiment of FIG. 8 is described in Table 14, and the tests of Table 15 were performed. The stagnation temperature for standard values ISO 9806-2 and EN 12975-2 were for 30° C./1000 W/m 2 , 269° C. The collector also passed a durability test. The thermal performance (flowrate at test: 179 l/h) is shown in FIGS. 12A and 12B , with and without wind, respectively.
TABLE 14
Contact
Paradigma-Schweiz, CH-6201 Sursee
Tel. +41 (041) 925 11 22,
Fax +41 (041) 925 11 21
Distributed in*
CH, DE, AT, *EU*, PL, HR
Type
Evacuated tube collector,
cylindrical absorbers, CPC,
direct heat transfer
Installation*
Installation on sloping roof,
Flat roof with support,
Facade installation
Rated flowrate*
180 l/h
Absorber coating*
Al/Al N
Dimensions
2.332 m 2 , 2.325 m 2 , 2.618 m 2
(absorber, aperture, gross)
Gross dimensions: l, w, h (in m)
1.613 × 1.623 × 0.120
Weight including glazing*
42 kg
*= manufacturer information
TABLE 15
Carried
Test
out
Section
Report*
Durability test according to ISO
Yes
3
C370QPISO
Durability test according to EN
Yes
3
C370QPEN
Measurement of stagnation temperature
Yes
3.1
C370QPEN
Efficiency measurement acc. SPF
Yes
4.1
LTS C370
Efficiency measurement acc
Yes
4.1
C370LPEN
ISO, DIN, EN
Incidence angle modifier (IAM)
Yes
4.4
Measurement of pressure drop
No
4.5
Measurement of thermal capacity
Yes
4.6
Measurement of time constant
No
4.6
*= contact manufacturer for details!
Tables 16A and 16B illustrate characteristic efficiency (normal incidence, G=800 W/m 2 ) for efficiency with and without wind, respectively. Table 17A and 17B show power output (power in watts per collector, normal incidence, beam irradiation) with and without wind, respectively.
TABLES 16A and 16B
Reference area
Absorber
Aperture
Gross
Reference area
Absorber
Aperture
Gross
η (T* m = 0.00)
0.68
0.68
0.60
η (x = 0.00)
0.68
0.68
0.60
η (T* m = 0.05)
0.59
0.60
0.53
η (x = 0.05)
0.60
0.60
0.54
η (T* m = 0.10)
0.50
0.51
0.45
η (x = 0.10)
0.52
0.52
0.46
TABLES 17A and 17B
Irradiation
400 W/m 2
700 W/m 2
1000 W/m 2
Irradiation
400 W/m 2
700 W/m 2
1000 W/m 2
t m − t e = 10K
593
1′065
1′537
t m − t e = 10K
597
1′069
1′541
t m − t e = 30K
517
989
1′461
t m − t e = 30K
528
1′000
1′472
t m − t e = 50K
437
909
1′381
t m − t e = 50K
455
928
1′400
Table 18 shows incidence angle modifier (IAM).
TABLE 18
0°
10°
20°
30°
40°
50°
60°
70°
80°
90°
K(Θ), long
1.0
0.90
0.0
K(Θ), trans
1.0
1.01
1.00
1.01
1.01
1.05
1.16
0.0
|
A solar collector with external reflector. A solar collector includes a glass housing having a heat pipe disposed within the housing and a light reflector disposed external to the housing.
| 5
|
[0001] This application claims the benefit under 35 USC §119(a)-(d) of German Application No. 20 2015 105 233.2 filed Oct. 5, 2015, the entirety of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a hinge for a movable furniture part that is fastened to a body of an item of furniture, and an item of furniture comprising such a hinge.
BACKGROUND OF THE INVENTION
[0003] A known hinge for a movable furniture part that is fastened to a body of an item of furniture comprises a hinge arm which is connected pivotably to a hinge cup via a joint mechanism. The hinge arm is fastened, for example, to a furniture body and the hinge cup is fastened to a furniture door. The joint mechanism comprises a four-bar linkage, and, during the closure of the furniture door, the four-bar linkage couples to a damping element which is formed on the hinge cup. In this way, a movement of the furniture door is damped in the process of closing the furniture door.
[0004] A disadvantage is that the damping element, in the assembled state, is arranged protruding from the surface of the furniture body on the hinge.
SUMMARY OF THE INVENTION
[0005] The object of the present invention is to improve a hinge for a movable furniture part fastened to a body of an item of furniture.
[0006] The present invention proceeds from a hinge for a movable furniture part, in particular, a door or flap, that is fastened to a body of an item of furniture. The hinge has a first attachment element, which is connected pivotably to a second attachment element via a joint mechanism, wherein the joint mechanism comprises at least one articulated lever, which is mounted pivotably on the first attachment element via a first bearing element.
[0007] When the hinge is in the assembled state on the item of furniture, the first attachment element is advantageously fastened to the movable furniture part, e.g. a door, and the second attachment element is fastened to the furniture body. A closing movement of the movable furniture part from an open position to a closed position on the furniture body thus corresponds, for example, to a closing movement of the hinge.
[0008] The essential aspect of the present invention is now considered to be that the articulated lever is arranged in a rotationally fixed manner on the first bearing element.
[0009] In this way, a pivoting movement of the articulated lever can be converted or transformed into a rotation movement of the bearing element.
[0010] Preferably, the joint mechanism comprises a first articulated lever and a second articulated lever. The joint mechanism can be configured, in particular, as a four-bar linkage.
[0011] A first articulated lever can be connected rigidly to the first bearing element. Advantageously, the first articulated lever is plugged, bonded, screwed, riveted and/or welded onto the first bearing element.
[0012] In an advantageous variant of the present invention, the first bearing element has an eccentric member, which acts on a damping element. In this way, a rotation movement of the joint mechanism of the hinge can be converted into an, in particular, linear damping movement of the hinge. In particular, a rotation movement of the bearing element can be converted into an, in particular, linear damping movement of the damping element. The damping movement of the damping element takes place, for example, along an axis of the damping element.
[0013] Advantageously, the damping element is arranged rigidly, for example, plugged, screwed and/or riveted, on an outer face of a side wall of the housing, in particular, in a fixed position relative to a housing of the first attachment element. The first attachment element is configured as a hinge cup, for example.
[0014] It is also conceivable that the damping element is arranged in the interior of the housing of the first attachment element, for example, on an inner face of the side wall of the hinge cup.
[0015] It is moreover proposed that the eccentric member is arranged in a rotationally fixed manner on the first bearing element. This has the advantage that a rotation of the bearing element is converted directly into a rotation of the eccentric member. For example, the eccentric member is bonded, screwed, riveted and/or welded onto the first bearing element.
[0016] Furthermore, it is advantageous that the first attachment element comprises a panel element, and the damping element, in the assembled state of the hinge on the item of furniture, is formed on the first attachment element on the side face of the panel element facing toward the item of furniture.
[0017] The first attachment element comprises, for example, a hinge cup and the panel element. By way of the panel element, the first attachment element can be secured on the item of furniture, for example, on the flap or door. For example, the panel element is designed in several parts.
[0018] Advantageously, the damping element is arranged on the panel element in such a way that, in the assembled state of the hinge or of the first attachment element on the item of furniture, the damping element is not visible to a person using the item of furniture.
[0019] For example, the damping element is arranged on the outer face of the side wall of the hinge cup in such a way that, in the assembled state of the hinge on the item of furniture, the damping element is concealed by the panel element and is not visible to a person using the item of furniture. The reason for this is, for example, that, looking at the item of furniture from above, the panel element of the hinge fitted on the item of furniture protrudes past the contour of the damping element.
[0020] It also proves advantageous that the first bearing element is configured as a shaft. For example, the first bearing element is mounted so as to be movable on the first attachment element, in particular, so as to be rotatable about its longitudinal axis, for example. An articulated lever connected to the bearing element is thus mounted pivotably, and an eccentric member connected to the bearing element is thus mounted rotatably. In this way, a torque of the articulated lever can advantageously be transmitted via the shaft to the eccentric member.
[0021] An advantageous embodiment of the hinge is characterized in that a damping element and/or a bearing element and/or an eccentric member can be retrofitted on the hinge. In this way, the function of the hinge can be extended according to requirements.
[0022] The hinge can be configured in such a way that a damping element and/or a bearing element and/or an eccentric member is arranged exchangeably or releasably. Advantageously, a hinge function of the hinge is provided without an arranged damping element and/or an arranged eccentric member.
[0023] In an advantageous variant of the hinge, the eccentric member is arranged on the first bearing element on an outer face of the housing of the hinge, e.g. an outer face of a hinge cup. In this way, the eccentric member can act directly on the damping element. For example, the eccentric member is rigidly connected to the damping element.
[0024] It is also advantageous that the eccentric member has a guide member.
[0025] Advantageously, the guide member is configured as an outer track or slotted guide. For example, the guide member is arranged on a side surface or on an outer edge of the eccentric member in such a way that the eccentric member acts on the damping element, particularly during a rotation movement of the bearing element.
[0026] In an advantageous variant of the eccentric element, the guide member, in particular, the outer track or the slotted guide, executes an eccentric movement. The outer contour of the eccentric member, viewed from the side, can have a droplet shape, and the guide member can be configured as a partial area of the droplet contour. In this way, an action of the eccentric member on the damping element, for example, in the course of a closing movement, can be strengthened.
[0027] According to an advantageous modification of the present invention, a guide element is formed on the damping element.
[0028] The guide element is preferably configured in such a way that the guide member and/or the eccentric member and/or the bearing element are coupled to the guide element such that a closing movement of the hinge, in particular, of the joint mechanism of the hinge, is damped, or, in the assembled state of the hinge on the item of furniture, a closing movement of the movable furniture part is damped.
[0029] It is also conceivable that the damping element and the eccentric member are connected to each other via the guide member and/or the guide element, in particular, rigidly connected to each other.
[0030] For example, a slotted guide and/or a contour is formed on the guide element.
[0031] The eccentric member and/or the guide member cooperate with the slotted guide and/or the contour of the guide element, for example, in such a way that the rotation movement of the bearing element and/or of the eccentric member is converted into a linear movement of the guide element. It is thus possible to achieve a damping action of the damping element during a closing movement of the hinge and/or, in the assembled state of the hinge on the item of furniture, during a closing movement of the movable furniture part.
[0032] It is also advantageous that a control member is formed on the eccentric member.
[0033] The control member is formed on the eccentric member and/or on the bearing element, for example, in such a way that it acts eccentrically on the damping element. Advantageously, it is an eccentrically arranged pin which moves in the guide element arranged on the damping element, for example, a slotted guide of the guide element.
[0034] It is further proposed that the joint mechanism comprises a second bearing element, and a further eccentric member is formed on the second bearing element.
[0035] Preferably, the second bearing element is formed on the second attachment element, and the first articulated lever is connected pivotably to the second attachment element via the second bearing element. Moreover, a further damping element can be present on the second attachment element and can advantageously cooperate with the further eccentric member of the second bearing element. This has the advantage that both a closing movement and also an opening movement of the hinge is damped and/or, in the assembled state of the hinge on the item of furniture, a closing and opening movement of the movable furniture part is damped.
[0036] It also proves advantageous that the second bearing element is arranged on the first attachment element.
[0037] For example, the second bearing element is mounted movably as a shaft on the first attachment element; alternatively, the second bearing element can also be configured as a stationary joint axle and/or bearing bolt and/or bearing pin.
[0038] In another advantageous embodiment of the hinge, the second articulated lever of the joint mechanism is coupled to the second bearing element, in particular, rigidly connected thereto.
[0039] By means of a differently configured rotation movement of the first bearing element in relation to a rotation movement of the second bearing element during a closing or opening movement of the hinge and/or an advantageous configuration of a single eccentric member on the first and on the second bearing element, the single eccentric member can advantageously execute an eccentrically acting movement and couple to a damping element in such a way that a movement of the hinge is damped and/or, in the assembled state of the hinge on the item of furniture, a movement of the movable furniture part is damped, in particular, a closing movement of the hinge and/or of the movable furniture part.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] Further features and advantages of the present invention are explained in more detail on the basis of illustrative embodiments depicted schematically in the figures.
[0041] FIGS. 1-4 each show in a perspective view, and in different positions (except for FIGS. 1 and 2 which show an open position), a first variant of a hinge according to the present invention;
[0042] FIGS. 5-6 each show in a perspective view, in an open position, a second variant of a hinge according to the present invention, the hinge being shown only partially in FIG. 6 ;
[0043] FIGS. 7-8 each show the hinge from FIG. 5 in a perspective view in a closed position, the hinge being shown only partially in FIG. 8 ;
[0044] FIG. 9 shows a perspective view of an item of furniture with two hinges, in an open position of a furniture door;
[0045] FIG. 10 shows a side view of the hinge from FIG. 5 in an open position;
[0046] FIG. 11 shows a side view of the hinge from FIG. 5 in a closed position; and
[0047] FIG. 12 shows a perspective view of the hinge from FIG. 5 in an exploded representation.
DETAILED DESCRIPTION OF THE INVENTION
[0048] A hinge 1 according to the present invention comprises an attachment element, which is formed as hinge arm 2 , a further attachment element, which is formed as housing 3 , consisting of a hinge cup 4 , and a panel element 5 arranged on the hinge cup 4 , and articulated levers 6 , 7 which form parts of a four-bar linkage and connect the hinge arm 2 and the housing 3 in an articulated manner via bearing elements 8 - 11 ( FIGS. 1-4 ).
[0049] On an outer face 12 of the housing 3 , in particular, of the hinge cup 4 , an eccentric member 13 is arranged on the extended bearing element 10 . The eccentric member 13 is connected rigidly to the bearing element 10 , particularly in a rotationally fixed manner. The bearing element 10 is preferably configured as a shaft and is mounted rotatably on the hinge cup 4 . Moreover, the bearing element 10 is connected to the articulated lever 6 in a rotationally fixed manner.
[0050] The bearing element 11 is configured, for example, as a bolt or shaft and is pinned in a rotationally fixed manner to the hinge cup 4 . The articulated lever 7 is mounted rotatably on the bearing element 11 .
[0051] Moreover, a damping element 14 comprising a housing 15 and a damper ram 16 is formed on the outer face 12 of the housing. The damping element 14 is advantageously configured as an oil damper.
[0052] A holding member 17 in the form of a pin can be arranged fixedly on the outer face 12 of the housing 3 . The holding member 17 is connected to the damper ram 16 of the damping element 14 by a spring 18 .
[0053] The hinge arm 2 of the hinge 1 can be pivoted from an open position of the hinge 1 ( FIGS. 1 and 2 ) via an intermediate position ( FIG. 3 ) to a closed position ( FIG. 4 ) and/or vice versa.
[0054] In the open position, the eccentric member 13 and the damper ram 16 of the damping element 14 are not in contact with each other; in particular, the two are not coupled to each other. The spring 18 is untensioned, or is at least under comparatively slight pretensioning, and the damping element 14 is situated in a pretensioned state.
[0055] The two identical hinges 1 are mounted on an item of furniture 19 , connecting the furniture door 20 to the furniture body 21 in an articulated manner ( FIG. 9 ). When a user closes the furniture door 20 on the item of furniture 19 , the hinge 1 is also moved from the open position to the closed position via the intermediate position.
[0056] The eccentric member 13 has, in a side view, a droplet-shaped contour, for example. A partial area of the droplet-shaped contour is an outer edge of an eccentrically acting surface 22 of the eccentric member 13 . The partial area can be circular or elliptic in outline or have another curved shape.
[0057] The eccentric member 13 is arranged on the bearing element 10 in such a way that a rotation of the bearing element 10 and therefore of the eccentric element 13 , in particular, during a closing movement of the hinge 1 , brings the surface 22 e.g. in the area of the intermediate position of the hinge 1 in contact with a pressing surface 23 of the damper ram 16 . Once the contact is made, the eccentric element 13 exerts through the surface 22 a pressing force on the damper ram 16 during the further closing movement. In this way, the rotation movement of the bearing element 10 is converted into a linear movement of the damper ram 16 .
[0058] On account of the damping, elastic and/or resilient configuration of the damping member 14 , the damper ram 16 counteracts the pressing force of the eccentric member 13 with an oppositely directed and advantageously lesser force. In this way, the closing movement of the hinge 1 is damped, and therefore, for example, also the closing movement of the furniture door 20 .
[0059] In the closing movement of the hinge 1 , the spring 18 is tensioned by the movement of the damping member 14 . In this way, the spring 18 additionally counteracts the closing movement of the hinge 1 and therefore, for example, also the closing movement of the furniture door 20 with an advantageous damping action.
[0060] Advantageously, during opening of the hinge 1 , the spring 18 supports a relaxation of the damping element 14 by a tensile force which, for example, is directed counter to the direction of the pressing force on the damper ram 16 . In this way, the damper ram 16 of the damping element 14 returns comparatively more quickly to a starting position for a renewed closing operation.
[0061] In a further variant of a hinge 24 , a pin-shaped control member 26 is arranged eccentrically on a further eccentric disk 25 , which is arranged on the bearing element 10 . The control member 26 is arranged, for example, at a distance from a rotation axis of the bearing element 10 on the eccentric disk 25 . In this way, during a rotation of the eccentric disk 25 about a rotation axis of the bearing element 10 configured as a shaft, the control member 26 moves in a circular path about the rotation axis ( FIGS. 5-7 ).
[0062] A guide element 29 in the form of a plate with a banana-shaped inner contour or with a curved oblong hole is arranged on a damper ram 27 of a damping element 28 of the hinge 24 . The control member 26 is guided in the inner contour of the guide element 29 . Moreover, the damping element 28 is secured by screws 30 , 31 on the underside of the panel element 5 so as to be concealed from a user when the hinge 24 is in the assembled state on the item of furniture 19 ( FIG. 8 ).
[0063] By virtue of the, for example, at least partial circular movement of the control member 26 in an opening or closing movement of the hinge 24 and the advantageous configuration of the inner contour of the guide element 29 , the control member 26 can be coupled to the guide element 29 in such a way that a rotation movement or pivoting movement of the hinge arm 2 of the hinge 24 is converted into a linear movement of the damping element 28 . In this way, an opening and/or closing movement of the hinge 24 is advantageously damped.
LIST OF REFERENCE SIGNS
[0000]
1 , 24 hinge
2 hinge arm
3 housing
4 hinge cup
5 panel element
6 - 7 articulated lever
8 - 11 bearing element
12 outer face
13 eccentric member
14 , 28 damping element
15 housing
16 , 27 damper ram
17 holding member
18 spring
19 item of furniture
20 furniture door
21 furniture body
22 surface
23 pressing surface
25 eccentric disk
26 control member
29 guide element
30 - 31 screw element
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A hinge, for a movable furniture part, in particular, a door or flap, that is fastened to a body of an item of furniture, wherein the hinge has a first attachment element, which is connected pivotably to a second attachment element via a joint mechanism, wherein the joint mechanism comprises at least one articulated lever, which is mounted pivotably on the first attachment element via a first bearing element. The hinge is characterized in that the articulated lever is arranged in a rotationally fixed manner on the first bearing element.
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This is a Divisional of U.S. application Ser. No.: 10/660,490, filed Sep. 12, 2003, which issued as U.S. Pat. No. 7,189,657 on Mar. 13, 2007, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of surface protection of a semiconductor substrate for maintaining a clean surface of a semiconductor substrate, in particular silicon semiconductor substrate in a condition in which it is not contaminated with organic substances.
1. Description of Related Art
Typically, in a prior art method of cleaning a semiconductor substrate, a highly clean surface condition is produced by removing the natural oxide film and contaminating substances using chemicals such as hydrofluoric acid, ammonia/hydrogen peroxide, sulfuric acid/hydrogen peroxide, or hydrochloric acid/hydrogen peroxide. In recent years, with advances in semiconductor integration, it has become necessary to perform higher semiconductor surface cleanness and maintain such a condition.
Specifically, various types of contaminating substances adhere to the surface of a semiconductor substrate during the manufacturing steps, so, in order to respond higher integration, it has become necessary not only to remove minute particles of small diameter, metals or organic substances adhering in the manufacturing steps, but also to prevent adhesion of organic substances while the substrate is left to stand between washing and the next step.
Typically, organic substances are present in the air in the clean room and adhere readily and in a short time simply on exposure thereto. As a temporary method of preventing this, currently, a mini-environment technique or a method of organic substance removal using a chemical filter is employed.
However, the prior art methods described above are subject to the following problems. In the case of a mini-environment, a pot or the like is employed and the substrate must be held therein in a sealed condition, so the need for this pot and interfaces and so on for opening and closing the pot require enormous investment.
Also, chemical filters must be provided for example at the air inlet of the manufacturing device/clean room, and regularly changed, which also requires enormous investment.
In view of the above, an object of the present invention is to provide a semiconductor substrate surface protection method whereby the adhesion of contaminating substances in the stages after a clean surface has been obtained can be conveniently prevented and such a surface can be maintained without requiring enormous investment.
SUMMARY OF THE INVENTION
In order to achieve the above object, A method of depositing chemical protection material on the surface of a semiconductor substrate, i.e., a semiconductor substrate surface protection method according to the present invention comprise: washing a semiconductor substrate; and depositing a high molecular straight-chain organic compound on the surface of said semiconductor substrate during or after washing of said semiconductor substrate.
With the method of protection according to the present invention, the surface condition of the semiconductor substrate after a clean surface is obtained can be maintained in a convenient fashion without requiring enormous investment.
Also, actions due to organic contaminating substances are prevented and the high molecular straight-chain organic compound can be removed by the processing temperature of subsequent steps, so the clean surface can be maintained without any problems in the processing steps.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoings and other objects, features and advantageous of the present invention will be better understood from the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is an illustration of a semiconductor substrate surface protection method according to a first embodiment of the present invention;
FIG. 2 is an illustration of the effect of the semiconductor surface protection method according to the first embodiment of the present invention;
FIG. 3 is an illustration of a semiconductor surface protection method according to a second embodiment of the present invention; and
FIG. 4 is an illustration of a semiconductor surface protection method according to a third embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of this invention will be described below with reference to the drawings. Note that in the drawings, the form, magnitude, and positional relationships of each constitutional component are merely illustrated schematically in order to facilitate understanding of this invention and no particular limitations are placed on this invention thereby. Further, although specific materials, conditions, numerical value conditions, and so on are used in the following description, these are merely one preferred example thereof and therefore do not place any limitations on this invention. It is to be understood that similar constitutional components in the drawings used in the following description are allocated and illustrated with identical reference symbols, and that duplicate description thereof has occasionally been omitted.
FIG. 1 is an illustration of a semiconductor substrate surface protection method according to a first embodiment of the present invention.
First of all, washing of a semiconductor substrate 1 is performed using a prior art method, as shown in (a) of FIG. 1 ; a high molecular straight-chain organic compound 3 is deposited on the highly clean surface 2 as shown in (b) of FIG. 1 immediately after the highly clean surface 2 of the semiconductor substrate 1 has been generated, or during washing.
1′ shows the condition in which the high molecular straight-chain organic compound 3 has been deposited on the highly clean surface 2 of the semiconductor substrate 1 .
A high molecular straight-chain organic compound 3 as referred to herein is a substance which does not easily evaporate from the surface even when the wafer is left to stand at ordinary temperature. For the high molecular straight chain organic substance 3 , a substance of lower boiling point than the temperature of the usual heat treatment may be selected. It can therefore be removed before the actual heat treatment in the following heat treatment step.
The heat treatment of the following step is typically for example thermal oxidation or reduced pressure CVD; the heating temperature is about 700° C. to 1100° C. in the case of thermal oxidation and 500° C. to 800° C. in the case of reduced pressure CVD.
The high molecular straight-chain organic compound 3 deposited on the surface is selected from substances of lower boiling point than this heating temperature. The high molecular straight-chain organic compound 3 is preferably a compound that does not contain unsaturated bonds. Also, as the high molecular straight-chain organic compound 3 , preferably a single straight-chain organic compound is employed.
The following organic compounds may be listed as examples of the high molecular straight-chain organic compound 3 :
(1) cholesterin (C 27 H 46 O): molecular weight 386.66, boiling point 233° C.; and
(2) behenic acid (C 21 H 43 COOH): molecular weight 340.57, boiling point 306° C.
As such organic compounds 3 , high molecular compounds for example as set out at pp. 268 and 269 of the reference “Chemical contamination in the semiconductor process environment and counter-measures therefor” by Realize Inc. may be employed. If such a high molecular compound is employed, substitution with organic substances that are injurious in semiconductor manufacture cannot occur.
As described above, with the method of surface protection according to the first embodiment of the present invention, by depositing the high molecular straight-chain organic compound 3 on the highly clean surface 2 of the semiconductor substrate 1 as shown in FIG. 2 , the organic compound 3 that has once adhered to the surface does not readily evaporate therefrom, so contamination of the highly clean surface 2 by the action of high molecular straight-chain organic contaminating substances 4 cannot occur.
Also, the high molecular straight-chain organic compound 3 is eliminated from the highly clean surface 2 of the semiconductor substrate during the heat treatment step of the semiconductor manufacturing step, so the heat treatment step can be performed without being affected by organic compound 3 adhering to the semiconductor substrate 1 .
FIG. 3 is an illustration of a method of semiconductor substrate surface protection according to a second embodiment of the present invention.
First of all, washing of a semiconductor substrate 1 is performed using a prior art method; a high molecular straight-chain organic compound 3 is deposited on the highly clean surface 2 immediately after manufacture of the highly clean surface 2 , or during washing. As the method of this deposition, a high molecular straight-chain organic compound 3 may be deposited onto a substrate surface 2 by discharging a liquid containing a high molecular straight-chain organic compound 3 as already described in the first embodiment and pure water from a spray nozzle 5 while rotating the semiconductor substrate 1 .
As described above, with the second embodiment, the benefit may be expected that the high molecular straight-chain organic compound 3 is uniformly deposited on the semiconductor substrate surface 2 .
FIG. 4 is an illustration of a semiconductor substrate surface protection method according to a third embodiment of the present invention.
First of all, washing of a semiconductor substrate 1 is performed using a prior art method; a high molecular straight-chain organic compound 3 is deposited on the surface of a semiconductor substrate 1 as described in the first embodiment immediately after manufacture of the highly clean surface, or during washing.
As the method of this deposition, the semiconductor substrate 1 , which is arranged in upright fashion in a semiconductor substrate accommodating vessel 7 , is inserted into a tank 6 into which high molecular straight-chain organic compound 3 as already described in the first embodiment has been admixed, and is carefully pulled up from the tank 6 when the high molecular straight-chain organic compound 3 has been deposited on the surface of the semiconductor substrate 1 . That is, this is a method employing immersion in a bath of a solution containing the high molecular straight-chain organic compound 3 and pure water.
As described above, with the third embodiment, the benefit may be expected that the high molecular straight-chain organic compound 3 is uniformly deposited on the surface of the semiconductor substrate 1 . Also, with this method, the high molecular straight-chain organic compound 3 may be deposited on to a plurality of semiconductor substrates 1 at the same time.
Preferably, if the high molecular straight-chain organic compound 3 is a compound containing the COOH group, the benefit of more uniform disposition onto the surface of the semiconductor substrate 1 can be expected.
Further according to the present invention, a cleaned wafer is coated with a high molecular, straight-chain organic oxide having a boiling point lower than the temperature of heat treatment of the wafer processing of the subsequent step.
(1) By employing high molecules, the coating condition can be safely maintained. The reason for this is that, in adsorption of organic substances, organic substances of low molecular weight are the first to be adsorbed, so by substituting these with high molecules, a superior coating condition can be produced. In contrast, if the surface is initially coated with a high molecular organic substance, the probability of substitution by other substances is abruptly reduced, so a superior coating condition cannot be achieved.
(2) When performing wafer treatment such as etching or CVD film formation, the aforesaid high molecular organic substance is required to be easily releasable, without being left behind as a residue on the wafer. Broadly, there are three types of high molecular organic substances, namely, straight-chain organic compounds, cyclic compounds (without double bonds) or cyclic double-bond compounds. Of these, straight-chain organic compounds satisfy the above object and can be sufficiently removed with the temperatures and atmospheres employed in semiconductor manufacture. For this reason, this type was selected.
(3) Also, supplementary to (2) above, by selecting a substance of lower boiling point than the heat treatment temperature of the wafer processing of the next step, this substance can be removed prior to actual heat treatment by the heat treatment of the next step.
It should be noted that the present invention is not restricted to the above embodiments and various modifications are possible based on the gist of the present invention; these are not excluded from the scope of the present invention.
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A semiconductor substrate surface protection method for maintaining surfaces thereof clean includes providing a tank containing pure water and a chemical protection material which is a high molecular straight-chain organic compound; and immersing the semiconductor substrate in the tank to deposit the high molecular straight-chain organic compound on the semiconductor substrate for maintaining the surfaces thereof clean. This convenient method prevents deposition of contaminating substances directly onto the semiconductor substrate and enables maintaining of this contaminant-free surface at a low cost.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a private branch exchange (PBX). More particularly, the present invention relates to a digital private branch exchange system for switching a short message service and a switching method.
[0003] 2. Background of the Related Art
[0004] Generally, a private branch exchange is an exchange for switching between extension lines in a business site such as an office, a company, a factory, a hotel, etc. or for switching between an extension line and an office line. Methods for providing a short message service (SMS) to users of the extension lines connected to the private branch exchange by using the private branch exchange are being researched.
[0005] [0005]FIG. 1 is a construction view of a related art digital private branch exchange for switching the SMS. As shown in FIG. 1, a digital private branch exchange 10 for switching the SMS converts an SMS signal received through an office line such as a public switched telephone network (PSTN), an integrated services digital network (ISDN), etc. into a format corresponding to an extension line terminal 90 and then switches into the extension line terminal 90 .
[0006] The extension line terminal 90 includes a single line terminal SLT for SMS 92 and a digital terminal 94 . The private branch exchange 10 includes: an analog office line interface unit 20 ; an ISDN office line interface unit 30 ; a voice mail interface unit 40 ; a SLT extension line interface unit 60 ; a digital terminal extension line interface unit 70 ; and a main processor 50 . The units 20 , 30 , 40 , 50 , 60 , and 70 are connected to one another by an SMS data bus 80 , and the main processor 50 controls SMS data exchange among the units.
[0007] The analog office line interface unit 20 interfaces with an analog office line such as the PSTN. The analog office line interface unit 20 includes an analog office line SMS unit 21 for detecting an SMS signal of a frequency shift keying (FSK) format transmitted through the analog office line and converting the detected SMS signal into SMS data. The SMS data can be data from the analyzed SMS signal.
[0008] The ISDN office line interface unit 30 interfaces with an ISDN office line. The ISDN office line interface unit 30 includes an ISDN office line SMS unit 31 for detecting an SMS signal of a pulse code modulation (PCM) format transmitted through the ISDN office line and converting the detected SMS signal into SMS data.
[0009] The voice mail interface unit 40 provides a voice mail service function. The voice mail interface unit 40 includes a digital signal processor (DSP) 41 for compressing voice and reproducing the compressed voice, and a memory 42 for storing the voice compressed by the DSP 41 .
[0010] The main processor 50 controls the entire private branch exchange 10 . The main processor 50 certifies an extension line terminal that will receive the SMS and transmit the SMS to the corresponding extension line terminal.
[0011] The SLT extension line interface unit 60 connects the SLT 92 and the private branch exchange 10 . The SLT extension line interface unit 60 includes a SLT extension line SMS unit 61 for converting SMS data transmitted from the main processor 50 into an SMS signal of an FSK format. The digital terminal extension line interface unit 70 connects the private branch exchange with the digital terminal 94 , and transmits SMS data transmitted from the main processor 50 to the corresponding digital terminal 94 .
[0012] Operations for switching SMS in the digital private branch exchange 10 will now be described. FIG. 2 shows a method for switching SMS in the digital private branch exchange. As shown in FIG. 2, if a speech path is connected between the private branch exchange 10 and the office line board (the analog office line interface unit 20 ) or the ISDN office line interface unit 30 before the SMS signal is received, the private branch exchange 10 certifies whether a corresponding SMS unit is connected to a corresponding office line board or not (S 12 ).
[0013] If the corresponding SMS unit is not connected to the corresponding office line board, the private branch exchange 10 finishes a procedure for receiving the SMS. However, if the corresponding SMS unit is connected to the corresponding office line board, the private branch exchange 10 finishes signaling for receiving the SMS by using the corresponding SMS unit and then receives the SMS signal (S 14 ). When the corresponding office line board is the analog office line interface unit 20 , the analog office line SMS unit 21 receives an SMS signal of an FSK format, and when the corresponding office line board is the ISDN office line interface unit 30 , the ISDN office line SMS unit 31 receives an SMS signal of pulse code modulation format.
[0014] The corresponding SMS unit which has received the SMS signal converts the SMS signal into SMS data and then transmits to the main processor 50 through the SMS data bus 80 . That is, the analog office line SMS unit 21 converts the SMS of an FSK format into the SMS data, and the ISDN office line SMS unit 31 converts the SMS signal of a PCM format into the SMS data (S 16 ).
[0015] The main processor 50 certifies that a receiving terminal of the SMS is an SLT or a digital terminal on the basis of the received SMS data (S 18 ). If the receiving terminal of the SMS (an extension line terminal which will receive the SMS data) is the SLT 92 , the main processor 50 certifies whether the SLT extension line interface unit 60 connected to the SLT 92 is provided with the SLT extension line SMS unit 61 or not (S 20 ). If the SLT extension line SMS unit is connected to the SLT extension line interface unit 60 , the main processor 50 transmits the SMS data to the SLT extension line interface unit 60 (S 22 ).
[0016] The SLT extension line SMS unit 61 of the SLT extension line interface unit 60 performs signaling with the SLT 92 (S 24 ), and converts the SMS data into an SMS signal of an FSK format then transmits the converted SMS signal of an FSK format to the SLT 92 (S 26 ). Then, the SLT 92 displays the received SMS signal on a display unit.
[0017] However, if the receiving terminal of the SMS (the extension line terminal which will receive the SMS data) is the digital terminal 94 (S 18 ), the main processor 50 transmits the SMS data to the digital terminal extension line interface unit 70 (S 28 ). The digital terminal extension line interface unit 70 transmits the SMS data to the corresponding digital terminal 94 (S 30 ). The digital terminal 94 displays the transmitted SMS data on the display unit.
[0018] As described above, the related art SMS switching PBX and methods have various disadvantages. For example, in the related art SMS switching private branch exchange, each port of the analog office line interface unit, the ISDN office line interface unit, and the SLT extension line interface unit has to be provided with an SMS unit for exclusive use. Thus, the SMS can not be provided through an office line or the SLT extension line to which an SMS unit is not connected for exclusive use.
[0019] The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
SUMMARY OF THE INVENTION
[0020] An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
[0021] One embodiment of the present invention provides an SMS switching private branch exchange system and method that can efficiently switch SMS without being provided with an SMS unit for exclusive use at an office line interface unit of a private branch exchange or at an SLT extension line interface unit. Another embodiment of the present invention provides an SMS switching private branch exchange system and method that can simultaneously realize functions of SMS signal detection, SMS signal generation, and voice mail service in one board with one chip set, in which a digital signal processor DSP used for voice compression decodes an SMS signal of a PCM format in a voice mail interface unit of a private branch exchange and generates a signal of a PCM format.
[0022] Another embodiment of the present invention provides an SMS switching private branch exchange system that can share a DSP for wholly performing functions of SMS signal detection, SMS signal generation, and voice mail service as a system resource. Another embodiment provides a method for accomplishing the same.
[0023] Another embodiment provides an SMS switching private branch exchange system that can include an office line interface unit which interfaces with an office line; a voice mail interface unit which converts a PCM format SMS signal transmitted from the office line interface unit into SMS data, and converting a format of the SMS data corresponding to a kind of a terminal that will receive SMS; a control unit which switches a PCM channel of an office line to which a speech path is connected into a PCM channel of a usable DSP, and certifying a kind of a terminal which will receive SMS; and an extension line interface unit which transmits an SMS signal having a format corresponding to a kind of the terminal certified by the control unit.
[0024] Another embodiment provides a method for switching SMS of a private branch exchange system that can include certifying whether a usable DSP exists or not when an office line and a speech path are connected to each other; transmitting an SMS signal transmitted from the office line to the DSP if the usable DSP exists; certifying an extension line terminal which will receive the SMS signal; and transmitting the SMS signal to the certified extension line terminal from the DSP.
[0025] Another embodiment provides a method for switching SMS of a private branch exchange system that can include switching a PCM channel of an office line interface unit into a PCM channel of a usable DSP if a speech path is connected to the office line interface unit; transmitting an SMS signal to the DSP from the office line interface unit through the PCM channels; decoding the SMS signal transmitted to the DSP; switching the PCM channel of the DSP into a PCM channel of an SLT extension line interface unit if an extension line terminal which will receive the SMS signal is an SLT; and switching an SMS data channel of the DSP into an SMS data channel of a digital terminal extension line interface unit if an extension line terminal which will receive the SMS signal is a digital terminal.
[0026] Another embodiment provides a private branch exchange system that can include a single digital signal processor that receives a short message service signal in a first format and converts the short message service signal in to a second format and a controller that controls the digital signal processor and determines the second format.
[0027] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:
[0029] [0029]FIG. 1 is a diagram showing a related art digital private branch exchange for exchanging SMS;
[0030] [0030]FIG. 2 shows a related art method for switching SMS in a digital private branch exchange;
[0031] [0031]FIG. 3 is a diagram showing an SMS switching private branch exchange system according to a preferred embodiment of the present invention; and
[0032] [0032]FIGS. 4A and 4B are flowcharts that show a method for switching SMS in a private branch exchange system according to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] [0033]FIG. 3 is a diagram showing construction of an SMS switching private branch exchange system according to a preferred embodiment of the present invention. As shown in FIG. 3, an SMS switching private branch exchange system can convert an SMS signal received through an office line such as a public switched telephone network (PSTN), an ISDN, etc. into a format corresponding to an extension line terminal by using a shared DSP (e.g., shared by time division), and then switches to the corresponding extension line terminal.
[0034] As shown in FIG. 3, an extension line terminal 200 can includes a SLT for SMS 210 ; and a digital terminal 220 . A private branch exchange system 100 can include: an analog office line interface unit 110 ; an ISDN office line interface unit 120 ; a voice mail interface unit 130 ; an SLT extension line interface unit 150 ; a digital terminal extension line interface unit 160 ; and a main processor 140 .
[0035] The analog office line interface unit 110 , the ISDN office line interface unit 120 , the voice mail interface unit 130 , the SLT extension line interface unit 150 , and the main processor 140 are preferably coupled to one another by a PCM bus 170 . Also, the voice mail interface unit 130 , the digital terminal extension line interface unit 160 , and the main processor 140 are preferably coupled to one another by an SMS data bus 180 . The analog office line interface unit 110 interfaces with an analog office line such as a PSTN, etc. The analog office line interface unit 110 can include a CODEC 111 for performing a conversion between an SMS signal of a frequency shift keying (FSK) format and an SMS signal of a PCM format.
[0036] The ISDN office line interface unit 120 interfaces with an ISDN office line. The ISDN office line interface unit 120 transmits/receives an SMS signal of a PCM format between an ISDN office line and the PCM bus 170 preferably by a control of the main processor 140 . The voice mail interface unit 130 can perform functions of SMS signal decoding, SMS signal generation, and voice mail service. The voice mail interface unit 130 can include a digital signal processor (DSP) 131 for compressing voice, reproducing the compressed voice, converting an SMS signal of a PCM format into SMS data, and generating an SMS signal of a PCM format from SMS data; and a memory 132 for storing the compressed voice and decoded SMS data. The main processor 140 can control the entire private branch exchange system 100 , and switch an SMS signal of a PCM format and SMS data according to an extension line terminal.
[0037] The SLT extension line interface unit 150 couples an SLT 210 and the private branch exchange system 100 . The SLT extension line interface unit 150 can include a CODEC 151 for performing a conversion between the switched SMS signal of a PCM format and an SMS signal of an FSK format received from an SLT 210 . The digital terminal extension line interface unit 160 couples the private branch exchange system 100 and the digital terminal 220 .
[0038] Operations of the private branch exchange system according to an embodiment of the present invention will now be described. If a speech path for SMS is coupled through a specific office line, the private branch exchange system 100 certifies whether a usable conversion unit such as DSP 131 exists or not. If the usable DSP 131 exists, an SMS signal is received from a corresponding office line and the received SMS signal is converted into SMS data through the DSP 131 . The private branch exchange system 100 preferably converts a format of the SMS data according an extension line terminal that will receive the SMS data, and switches to a corresponding extension line terminal.
[0039] [0039]FIGS. 4A and 4B show a method for switching SMS in a private branch exchange system according to a preferred embodiment of the present invention. The method shown in FIGS. 4 A- 4 B will be exemplarily described using the PBX 200 . However, the present invention is not intended to be so limited. As shown in FIGS. 4A and 4B, if a speech path for SMS is coupled through a specific office line before receiving an SMS signal (S 00 ), the main processor 140 of the private branch exchange system 100 certifies whether the usable DSP 131 exists in the voice mail interface unit 130 (S 102 ).
[0040] If the usable DSP 131 does not exist at present, the main processor 140 waits for a period of time and then certifies again whether the usable DSP 131 exists or not (S 104 ). If the usable DSP 131 exists, the main processor 140 can switch a PCM channel of an office line to which the speech path is coupled into a PCM channel of the DSP 131 (S 106 ). When the office line to which the speech path is coupled is a PSTN office line, the analog office line interface unit 110 of the private branch exchange system 100 converts an SMS signal of an FSK format transmitted through an analog office line into an SMS signal of a PCM format preferably through the CODEC 111 , and carries the converted SMS signal of the PCM format on the PCM bus 170 . When the office line to which the speech path is coupled is an ISDN office line, the IDSN office line interface unit 120 of the private branch exchange system 100 carries an SMS signal of a PCM format transmitted through an IDSN office line on the PCM bus as it is (S 108 ).
[0041] The main processor 140 performs signaling for receiving an SMS signal and then starts to receive an SMS signal (S 110 ). The DSP 131 decodes the SMS signal of the PCM format carried on the PCM bus 170 and converts it to SMS data (S 112 ). The converted SMS data can be stored in the memory 132 of the voice mail interface unit 130 (S 114 ) transmitted or the like.
[0042] The main processor 140 can determine or certify whether an extension line terminal that will receive the SMS data is a digital terminal or an SLT (S 116 ). If the extension line terminal that will receive the SMS data is an SLT 210 , the main processor 140 switches a PCM channel of an extension line that will receive the SMS data into a PCM channel of the DSP 131 (S 118 ). Then, the main processor 140 performs signaling with the SLT 210 that will receive the SMS (S 120 ). If the signaling with the SLT 210 is completed, the DSP 131 converts the SMS data stored in the memory 132 into an SMS signal of a PCM format and then transmits the signal on the PCM bus 170 (S 122 ).
[0043] The SLT extension line interface unit 150 converts the SMS signal carried on the PCM bus 170 into an FSI format preferably through the CODEC 151 , and transmits the converted SMS signal of an FSK format to the SLT 210 (S 124 ). Then, the SLT 210 can preferably display the transmitted SMS signal on a display unit.
[0044] In the step S 16 , if the extension line terminal that will receive the SMS data is the digital terminal 220 , the main processor 140 couples a SMS data channel of an extension line which will receive the SMS data with a SMS data channel of the DSP 131 . The DSP 131 transmits the SMS data stored in the memory 132 on the SMS data bus 180 as it is (S 126 ). Then, the digital terminal extension line interface unit 160 receives the SMS data carried on the SMS data bus 180 , and transmits the received SMS data to the digital terminal 220 (S 128 ). The digital terminal 220 displays the transmitted SMS data on a display unit.
[0045] Although preferred embodiments of systems and methods were described as signals originating from office lines for delivery to extension lines, the present invention is not intended to be so limited. For example, signals can be transmitted from extension lines for delivery to office lines according to preferred embodiments.
[0046] As described above, preferred embodiments of a PBX and methods thereof according to the present invention have various advantages. For example, according to preferred embodiments, a conversion function such as, the DSP, which can also be used for voice compression, decodes an SMS signal of a PCM format and generates SMS data in an SMS signal of a PCM format, so that functions of SMS signal detection, SMS signal generation, and voice mail service may be simultaneously realized preferably in one board with one chip set and the DSP may be shared as a system resource. Also, the SMS can be efficiently switched without providing an SMS unit for exclusive use at the office line interface unit, the IDSN office line interface unit, and the SLT extension line interface unit, respectively.
[0047] The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
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An short message service switching private branch exchange system and a method can reduce costs. The method can include certifying whether a usable DSP exists or not when an office line and a speech path are connected to each other, and transmitting an short message service signal transmitted from the office line to the DSP through a PCM channel if the usable DSP exists. A main processor of the private branch exchange can certify an extension line terminal that will receive short message service, generate an short message service signal having a format corresponding to a kind of the extension line terminal by using the DSP, and transmit the formatted SMS signal to an extension line interface unit of a corresponding extension line terminal. The system switches an SMS signal between an office line and an extension line by sharing the DSP, for example, by time division.
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This application is a continuation-in-part of Ser. No. 404,708 filed 8-3-82, now abandoned.
DESCRIPTION
This invention concerns an electronic biofeedback device, hereafter "analyzer," designed to aid voice students in producing the "singer's formant." This acoustic feature is a peak in the sound spectrum of tones produced by singers trained in the concert/operatic tradition. It imparts a characteristic timbre to the sound and makes it possible for a singer to be heard over an orchestra.
Utilizing electronic filter means, the analyzer separates the singer's formant from the sound as a whole and indicates its strength on a meter. As a singer changes factors such as breath pressure or articulatory positions, the effect of those changes upon the strength of the singer's formant can be seen simultaneously on the meter. The sounds of speech, the piano, and orchestral instruments show little or no response on the meter. By noting the aural, tactile, and kinesthetic sensations experienced as the meter indicates the amplitude of the singer's formant, a singer can develop vocal techniques which produce the desired characteristic. Thus the analyzer can function as a biofeedback device to control the vocal output.
Use of the analyzer tends to clarify certain directives which employ psychological imagery. For example, tones sung with a "forward placement" produce a higher meter reading than tones which are "back." Differences in the amplitude of the singer's formant with different vowels and different vocal qualities are also shown by the meter. While the response of the human perception mechanism to vocal tones varies, the response of the machine is consistent, thereby providing the singer with a steady reference point for monitoring his vocal efforts.
In the analyzer, a special electronic filter means separates the acoustical features constituting the singer's formant from the sound as a whole. The strength of this filtered component is measured by a moving coil meter, similar, for example, to the VU meter on a tape recorder. The relative amplitude of the singer's formant in a given sound is displayed by the meter as the sound is produced. Changes in the strength of the singer's formant resulting from changes in breath support, positions of the mouth, lips, and tongue, or other factors can be seen immediately on the meter. A sensitivity control permits adjusting the meter to accommodate a wide dynamic range.
Spectrum analyzers, as they are generally constructed, consist of a bank of filters, each tuned to standardized center frequencies, e.g., one-third octave apart, and encompassing a wide range of frequencies, e.g., 20-20,000 Hz. The energy present in each of these several bands or channels is displayed as a bar graph or as a line on an XY graph. Spectrum analyzers which sample the sound rapidly and constantly update the graph on a video screen or a matrix of LED's are termed "real-time" spectrum analyzers since changes in sound spectra can be observed on the displays in real time as they occur.
Spectrum analyzers like those described above are unsuited for the function of monitoring the singer's formant in a teaching/learning situation for several reasons. A principal problem with their use is that the frequency range of the singer's formant does not correspond to the standardized frequency ranges of the prior spectrum analyzers. Thus, while the energy present in the singer's formant can be monitored in a crude manner with such devices, the visual readings are not effective for monitoring the singer's formant as an independent entity since acoustic energy outside the frequency range of interest is also being displayed. Thus it is difficult with such devices for a singer to observe the effects of his efforts to strengthen the formant, e.g., by changing his breath pressure or the positions of the mouth, lips, and tongue.
The present analyzer differs from conventional spectrum analyzers in several respects as follows:
(1) It has filters which pass energy lying in the range of the singer's formant with little or no attenuation while sharply attenuating energy on all other frequencies, that is, the frequency-response curves at the ends of the pass-band window have steep slopes, while the frequency-response curve within the pass-band window is fairly flat or only slightly peaked;
(2) The frequency range of the filter system encompasses the slightly different center frequencies of the singer's formant which occur with different individual singers, male and female singers, and with different vowels;
(3) The analyzer is battery powered to maximize its flexibility of use in a variety of environments from the teaching studio to the practice room. The battery, preferably, is an ordinary nine-volt battery, desirable because of its wide availability and standard use in other electronic devices. Additionally, the present circuitry sharply reduces current drain and allows use of batteries. Moreover, the circuit design insures that the performance of the device is not significantly affected by decreases in power-supply voltage as the battery weakens over time;
(4) The input microphone has a relatively flat frequency response across the frequency range of interest. It also has a voltage output strong enough that further amplification is not required before the filter stages. Additionally, the microphone module is built into the case, as opposed to being an external device at the end of a cord, so that the device can be managed easily;
(5) The electronic design is such that individual units can be calibrated to a common standard of frequency response and sensitivity; and
(6) A wide dynamic range is accomodated so that the analyzer can be used by singers capable of producing a strong singer's formant and also by beginning singers capable of producing only a weak singer's formant. This is achieved by a variable sensitivity control, available for easy adjustment on the front panel.
In the present analyzer, there are four principal circuit functions as follows:
(1) A means for converting a voice sound to a corresponding electrical voltage. This is achieved by a microphone which preferably has a flat frequency response across the frequency range of interest (2500-3500 Hz), an output sufficient that further amplification is not required prior to the signal entering the filtering stage, a sensitivity unaffected by changes in battery supply voltage, since the power supply voltage preferably is clamped to +-3.1 volts by zener diodes, and which is physically small and inexpensive;
(2) A means for filtering the signal output of the microphone so that only those frequency components lying in the range 2500-3500 Hz are passed and all other frequencies are strongly suppressed. Several filtering schemes are possible. The arrangement in the circuit example, however, has the following desirable features:
(a) Very steep filter skirts, thereby sharply attenuating even nearby frequencies outside the overall pass-band of interest of from about 2500 to about 3500 Hz. This is achieved by cascading two narrow band-pass filters, the first tuned to a center frequency of about 3200 Hz, the second tuned to a center frequency of about 2750 Hz. The frequency pass-bands of each filter overlap, providing the aforesaid overall pass-band having steeper skirts than would be achieved by cascading a high-pass and low-pass filter;
(b) It uses a minimum of components, i.e., three sections of a quad opamp IC, eight resistors, and four capacitors, all of which are fixed and require no adjustment; and
(c) It possesses characteristics which are desirable in a filter but which are often mutually exclusive, i.e., high Q (selectivity), good stability (does not break into oscillation), and good dynamic range (works with both strong and weak signals).
(3) A means for rectifying the filtered signal so that its amplitude can be measured. Several schemes are possible, such as the use of singer diode, however, the exemplary circuit possesses a number of desirable features:
(a) It is a precision full-wave active rectifier. This allowes it to rectify signals across a wide dynamic range with equal response (passive rectifiers working with diodes do not work with signals under 0.6 volts and their characteristics vary with the individual diodes being used). A full wave rectifier provides a smoother DC output voltage than does a half-wave rectifier; and
(b) It uses the remaining opamp available on the quad opamp IC package used by the filter.
(4) A means for measuring the amplitude of the filtered component and displaying the amplitude in such a manner that it can be monitored in real time by a singer. Several schemes are possible, including a row of light emitting diodes (LED's) or a moving-coil meter. The example circuit uses a 200 microamp moving-coil meter because it involves fewer individual components, and requires fewer adjustments than would an LED configuration. The precision of the meter is unimportant in this application because the singer needs only to monitor the relative position of the needle as different sounds are produced. The specific values indicated by the meter, e.g., 120 microamps, has no relevance for the singer using the device as a biofeedback instrument for monitoring the singer's formant. Researchers using the device in research projects concerned with the singer's formant might use the specific values indicated on the meter face, however.
The accompanying schematic of an exemplary circuit for the present analyzer depicts the above functions and other preferred elements which enhance the overall operation and/or usefulness of the device, i.e.:
(a) A means for calibrating the device so that different individual units indicate the same meter readings with the same input signal. This is achieved in the example circuit by a variable resistor (R12) between the meter and ground. This resistor is mounted on the circuit board itself and is not accessible to the user of the device;
(b) A means for adjusting the sensitivity of the device so that it accomodates signals over a wide dynamic range, i.e., singers having very weak or strong singer's formants. This is achieved in the example circuit by a variable resistor (R11) between the microphone and the first filter stage. This resistor is mounted on the front panel, where it may be adjusted by the singer; and
(c) A means for powering the device with a single nine-volt battery, thereby permitting the machine to be portable and/or hand-held, while at the same time keeping the voltage level constant even as the battery power declines. This is achieved in the example circuit by a configuration employing zener diodes across the battery output. One zener diode (Z2) clamps its output to 6.2 volts (relative to the negative pole of the battery) while the other zener diode (Z1) clamps its output to 3.1 volts (relative to the negative pole of the battery). The device itself uses the 3.1 voltage point as its ground, using the negative pole of the battery as a source of -3.1 volts and the output of the Z2 as the source of +3.1 volts. The power supply voltage to the circuit is thus +3.1 volts and -3.1 volts, remaining at those set levels until the battery weakens to below 6.2 volts.
Referring further to the schematic, the sound is received by EM1, an electrolet microphone element which converts the sound into a corresponding electrical signal. The microphone is powered by six volts. The combination of R13 and Z2 insures that the nine volts from the battery is reduced to the six volts required by the microphone. The microphone signal is passed through an adjustable voltage divider (R11), which functions as a sensitivity control. This allows the device to be adjusted to accomodate a wide dynamic range. That is, weak signals can be amplified more so that they can be shown on the meter while strong signals can be amplified less so that they do not "pin" the needle of the meter.
The signal from the voltage divider is passed through a band-pass filter (U1) which is tuned to a center frequency of about 3200 Hz. The frequency of this filter is determined by C1, C2, R2, and R3, while the circuit Q (sharpness) and amplifier gain are determined by R3 and R4. U2 is a voltage follower, which matches the low impedance output of U1 to the high impedance input of the next filter section.
The signal next passes through another band-pass filter (C3, C4, R5, R6, U3, R7, R8), which is electrically identical to the first filter except it is tuned to a center frequency of about 2750 Hz. The net effect of the two band-pass filters in series is a filtering function where signals in the range 2500-3500 Hz are passed through while signals outside that range are sharply attenuated. The active rectifier consisting of U4, R9, R10, U1, and D1, and D2 provides a DC voltage for the 200 microamp meter (MI) Which displays the amplitude of the signal lying within the pass-band of the filters. The filter also has a voltage gain of approximately 3, set by the ratio R10/R9. A variable register (R12) between the meter and ground permits the sensitivity of the device to be sealed so that different units will show the same meter reading with the same input signal.
U1, U2, U3, and U4 are all contained in a single LM324 integrated circuit package. The power is supplied by B1, a nine-volt battery. Z1 and Z2 are zener diodes which clamp the voltage at -3.1 volts and 6.2 volts with respect to the negative pole of the battery. The circuitry of the filters and active rectifier use the 3.1 voltage point as ground, the negative pole of the batery as -3.1 volts, and the output of Z2 as +3.1 volts. R13 and R14 serve as current limiting resistors. S1 is an on/off switch, and J1 is a jack which permits bypassing the battery and using an external voltage source, such as an AC adapter.
One of the most important aspects of the present invention is the use of a unidimensional, real-time display means which displays visually the magnitude of the total formant energy only within the fixed passband. The unidimensional character of the display means is very important as it allows the singer to view, for example, only one reading on a hand held meter or one light which increases in intensity as the formant energy increases, in order to make an immediate assessment of the magnitude of his formant energy. This feature obviates the need for the singer to view other and extraneous energy characteristics of his voice such as vowel identification frequencies and energy levels associated with normal speech sounds, and allows him to immediately experiment with his breath pressure, articulatory position or the like to improve his vocal energy output within the formant range.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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Disclosed is a real-time spectrum analyzer for monitoring acoustic energy, in particular a singer's formant, comprising a microphone element for converting the energy of a singer's voice to an electrical signal, band-pass filters for filtering the signal and selectively passing a portion thereof in a dedicated frequency range of from about 2500 to about 3500 Hz corresponding to singer's formant to a display meter responsive to the portion for visually displaying the magnitude of the total energy of said portion, the band-pass filters being connected in series and tuned to different center frequencies but overlapping from about 20% to about 60% of the total pass-band.
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TECHNICAL FIELD
[0001] The present subject matter generally relates to the field of expression of biologically active proteins in host cells. More particularly the present subject matter relates to construction of an expression cassette with the protein of interest and methods for expressing the protein in host cells.
BACKGROUND
[0002] In the recent years, the discovery of methods for introducing DNA into living host cells in a functional form has provided the key to understand many fundamental biological processes. These methods are used to produce many important proteins and other molecules in commercially useful quantities.
[0003] Generally, the above disclosed methods includes several common problems that may limit the efficiency with which a gene encoding a desired protein can be introduced into and expressed in a host cell. A problem is distinguishing between the cells that contain the GOI (gene of interest) and the cells that have survived the transfer procedures but do not contain the GOI. Another problem is identifying and isolating the cells that contain the gene and that are expressing high levels of the protein encoded by the gene.
[0004] Further, identification and over-expression of novel genes associated with human disease is an important step towards developing new therapeutic drugs. The cloning of cDNA is carried to produce protein over-expression of cells and these cells are deposited in a depository library. Thus in order to identify a new gene using this approach, the gene must be expressed in the cells at sufficient levels to be adequately represented in the depository library. This is problematic because many genes are expressed only in very low quantities, in a rare population of cells or during short developmental periods.
[0005] Furthermore, because of the large size of some mRNAs it is difficult or impossible to produce full length cDNA molecules capable of expressing the biologically active protein. Lack of full-length cDNA molecules has also been observed for small mRNAs and is thought to be related to sequences in the message that are mammalian expression systems to produce by reverse transcription or that are unstable during propagation in bacteria. As a result, even the most complete cDNA depository libraries express only a fraction of the entire set of possible genes.
[0006] In the light of the aforementioned discussion, there exists a need for new methods and new full length constructs for constant expression of extremely valuable biologically active proteins in mammalian host cells.
BRIEF SUMMARY
[0007] The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the disclosure or delineate the scope of the invention.
[0008] Exemplary objective of the subject matter is to provide a DNA molecule comprising a primary transcriptional unit coding for promoter, synthetic intron, a selectable marker polypeptide functional in eukaryotic host cells, a polyadenylation signal or transcriptional terminator. The synthetic intron of the primary transcriptional unit contains second transcriptional unit coding for promoter and polypeptide of interest.
[0009] Another exemplary objective of the present subject matter is to provide a DNA molecule comprising a primary transcriptional unit coding for Promoter, Synthetic intron, a selectable marker polypeptide functional in eukaryotic host cells, a polyadenylation signal or transcriptional terminator. The synthetic intron of the primary transcriptional unit containing two transcriptional units encoding Promoter, amplifiable gene or a fluorescent reporter protein and promoter, polypeptide of interest.
[0010] Another exemplary objective of the present disclosure is, the selectable marker protein provides resistance against lethal and/or growth-inhibitory effects of a selection agent, such as an antibiotic.
[0011] Another exemplary objective of the present disclosure is to develop a regulatable expression of selectable marker protein using inducible promoter.
[0012] Another exemplary objective of the present disclosure is to develop a coding sequence of the polypeptide of interest comprising an optimal translation start sequence.
[0013] Another exemplary objective of the present disclosure is to develop a synthetic intron which can accommodate all the necessary sequences for better expression and capable of splicing.
[0014] Another exemplary objective of the present disclosure is to develop a synthetic intron which can be as long as 500 base pairs to 6000 base pairs and more.
[0015] In certain embodiments, the polypeptide of interest is a part of a multimeric protein, for example a heavy or light chain of an immunoglobulin. The invention also provides host cells comprising DNA molecules according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein:
[0017] FIG. 1 is a schematic representation of the use of multiple promoters in tandem to drive the expression of selectable marker gene and the polypeptide of interest.
[0018] FIG. 2 is a schematic representation of the use of multiple promoters in tandem to drive the expression of selectable marker gene, amplifiable gene/reporter protein gene and polypeptide of interest.
[0019] FIGS. 3A-3G are figures showing plasmids carrying varying lengths of synthetic intron.
[0020] FIGS. 4A-4C are figures showing construction of pUB-CE-100-N Plasmid.
[0021] FIGS. 5A-5C are figures showing construction of pUB-CE-100-N-GFP. pUB-CE-100-N-GFP was constructed by ligating BgIII and NotI fragment (3555bp) of pUB-CE-100-N with BgIII and Nod fragment (1540bp) of pUB-GFR
[0022] FIG. 6 is a figure showing comparison of expression between different vectors containing synthetic intron varying in size from 500 to 6000 base pairs.
[0023] FIG. 7 is a figure showing transient expression assay to test the functionality of pUB-CE-100-N-GFP plasmid.
[0024] FIG. 8 is a figure showing comparison of GFP expression between CHOK1 stable pools developed using pUB-GFP and pUB-CE-100-N-GFP
[0025] FIG. 9 is a figure showing comparison of GFP expression between GFP expressing stable pool and clone developed using pUB-CE-100-N-GFP
[0026] FIG. 10 is a figure showing construction of pUB-CE-100-N-Ab-Lc and pUB-CE-100-H-Ab-Hc Plasmids: pUB-CE-100-N-Ab-Lc was constructed by ligating BglII and NotI fragment (3555bp) of pUB-CE-100-N with BgIII and NotI fragment of (1510bp) of pUB-Ab-Lc plasmid.pUB-CE-100-H-Ab-Hc was constructed ligating BgIII and NotI fragment (3837bp) of pUB-CE-100-H with BgIII and NotI fragments (2224bp) of pUB-Ab-Hc plasmid.
[0027] FIG. 11 is a graph showing fed-batch study of mAb producing clone developed using pUB-CE-100-N-Ab-Lc and pUB-CE-100-H-Ab-Hc.
DETAILED DESCRIPTION
[0028] It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0029] The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms “first”, “second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.
[0030] FIG. 1 is a schematic representation of the use of multiple promoters in tandem to drive the expression of selectable marker gene and the polypeptide of interest in one transcriptional unit. Promoter-1-Synthetic intron-neomycin-Polyadenylation signal being the primary transcriptional unit and Promoter-2-Polypeptide of interest being the second transcriptional unit and is part of the synthetic intron.
[0031] According to an exemplary aspect of the present disclosure, transcription from promoter-1 results in expression of selectable marker gene due to splicing of synthetic intron formed by Splice donor (SD) and Splice acceptor (SA).
[0032] In accordance with a non limiting exemplary aspect of the present disclosure, transcription from promoter 2 results in the expression of polypeptide of interest as eukaryotic transcriptions are 5′ cap dependent. Polypeptide of interest will be expressed but not the selectable marker gene.
[0033] According to an exemplary aspect of the present disclosure, Promoter I can be inducible promoter to regulate the expression of selectable marker gene there by allowing better selection. Promoter 2 can be a constitutive promoter which can result in high expression of polypeptide of interest.
[0034] In accordance with a non limiting exemplary aspect of the present disclosure, cloning of Promoter 2 and Polypeptide of interest in the intron of primary transcriptional unit will generate 100% expressing stable pool for polypeptide of interest following selection. There by increasing the chances of isolation of high expressing cell line.
[0035] FIG. 2 is a schematic representation of the use of multiple promoters in tandem to drive the expression of selectable marker gene, amplifiable gene or reporter protein gene and Polypeptide of interest in one transcriptional unit. Promoter-1-Synthetic intron-Selectable marker gene-Polyadenylation signal is the primary transcriptional unit and Promoter-2-Amplifiable gene and Promoter 3-Polypeptide of interest are the secondary transcriptional unit cloned in the synthetic intron of primary transcriptional units in tandem. In accordance with a non limiting exemplary aspect of the present disclosure, transcription from promoter-1 results in expression of selectable marker gene due to splicing of synthetic intron formed by Splice donor-1(SD-1) and Splice acceptor (SA).
[0036] According to an exemplary aspect of the present disclosure, transcription from promoter 2 results in the expression of amplifiable gene or reporter gene. Eukaryotic transcriptions are 5′ cap dependent. Amplifiable gene or reporter protein will be expressed but not the selectable marker gene.
[0037] In accordance with a non limiting exemplary aspect of the present disclosure, transcription from promoter 3 results in the expression of polypeptide of interest as eukaryotic transcriptions are 5′ cap dependent. Polypeptide of interest will be expressed but not the selectable marker gene.
[0038] According to an exemplary aspect of the present disclosure, promoter 1 can be inducible promoter to regulate the expression of selectable marker gene there by allowing better selection and promoter 2 can be inducible promoter to regulate the expression of amplifiable gene or reporter protein gene which can be switched on as and when required. The promoter 3 can be a constitutive promoter which can result in high expression of polypeptide of interest.
[0039] In accordance with a non limiting exemplary aspect of the present disclosure, cloning of Promoter 2-amplifiable gene or reporter protein and Promoter 3-Polypeptide of interest in the intron of primary transcriptional unit will generate 100% expressing stable pool for amplifiable gene or reporter protein and polypeptide of interest following selection. The amplifiable gene or reporter protein will help better amplification or selection for high expressing cell line and all the cells expressing amplifiable gene will also express high amount of polypeptide of interest there by facilitating isolation of high expressing cell line.
[0040] In accordance with a non limiting exemplary aspect of the present disclosure the DNA molecules comprise of a sequence encoding a functional selectable marker polypeptide, characterized in that such DNA molecules comprise a mutation that decreases the translation initiation efficiency of the functional selectable marker polypeptide in a eukaryotic host cell. Preferably, such a DNA molecule comprises a GTG or a TTG start codon followed by an otherwise functional selectable marker coding sequence.
[0041] According to an exemplary aspect of the present disclosure, a method for generating host cells expressing a polypeptide of interest is disclosed. The method comprises of introducing an expression cassette to a plurality of precursor host cells, culturing the cells under conditions selecting for expression of the selectable marker polypeptide and selecting one or more host cell producing the polypeptide of interest.
[0042] In accordance with a non limiting exemplary aspect of the present disclosure methods for producing a polypeptide of interest is disclosed. The methods comprises of culturing a host cell and the host cell comprising an expression cassette and expressing the polypeptide of interest from the expression cassette. In preferred embodiments thereof, the polypeptide of interest is further isolated from the host cells and/or from the host cell culture medium.
[0043] According to an exemplary aspect of the present disclosure, the expression cassettes further comprises of at least one chromatin control element chosen from the group consisting of a matrix or scaffold attachment region (MAR/S AR), an insulator sequence, a ubiquitous chromatin opener element (UCOE) and an anti-repressor sequence. The expression cassettes are further positioned upstream of the promoter driving expression of the polypeptide of interest and downstream of the polypeptide of interest in the synthetic intron.
[0044] Referring to FIGS. 3A-3G are figures showing plasmids carrying varying lengths of synthetic intron. Plasmids used in this project were purified using different techniques for different applications. Plasmids used for cloning were routinely isolated by the alkaline lysis method or by using UB-Plasmid Mini Kit (Usha Biotech Ltd, Hyderabad). However, for transfection of mammalian cells, plasmids were isolated using the UB-Plasmid Midi Kit (Usha Biotech Ltd, Hyderabad)
Desalting of DNA
[0045] Digested plasmid DNA was routinely purified using UB-Desalting Kit.
Restriction Digestion
[0046] 5-10 ug of DNA was routinely digested with 1-5 units (U) of enzyme in the appropriate reaction conditions described by the manufacturer. The reaction was usually carried out in 20 ul reaction volume at the recommended temperature for 1-2 h. the DNA fragments were visualized in a UV transilluminator and gel documentation system (SynGene, Cambridge, UK) following electrophoresis on 0.8-1% agarose gel. Commercially available DNA size marker (1 kb and 100 by DNA ladders) were run along with the digested samples to compare and estimate the size of the restriction fragment.
Agarose Gel Electrophoresis
[0047] Plasmid DNA separation was routinely performed on 0.8 to 1% agarose gel in 1×Tris Acetic acid: EDTA (TAE) electroporation buffer pH 8.3 (2 mM Tris-Acetate/0.05 M EDTA). Agarose gels were cast in 1×TAE buffer containing 0.5 μg/ml of ethidium bromide. DNA samples were mixed with ⅙ th volume of 6×loading dye (NBE, Beverly, Mass.) and subjected to electrophoresis under controlled voltage of 5 V/cm. Appropriate DNA size markers (1 Kb or 100 bp DNA ladder) were run alongside the samples to estimate the size and concentration of the DNA fragments. The DNA was visualized in an UV transilluminator and gel documentation system (SynGene, Cambridge, UK).
Transient Transfection
Lipofection of CHO-K1
[0048] Lipofections were carried out using the Lipofectamine 2000 reagent (Invitrogen) according to the manufacturer's directions. Briefly, 5 ug of DNA in 250 ul of OptiMEM media and 15 ul of Lipofectamine 2000 in 250u1 of OptiMEM media were prepared at room temperature and incubated for 5 min. The DNA and lipofectamine2000 were combined and incubated together for a further 20minutes before adding to cells at 70 to 80% confluence in 6 well plate. Cells were analyzed using FACS (BD) after 48 hours.
Stable Transfection
Electroporation
[0049] Electroporation was routinely used for the development of stable cell line. CHO-K1 cells at an exponential growth phase (70-80% confluence) were detached with EDTA/PBS, washed once with 1×PBS and resuspended at 5×10 6 cells/ml in electroporation buffer. 200 ul of resuspended cells were aliquoted into an electroporation cuvette (2 mm) (sigma) and 2 μg of linear DNA was added to the cuvettes, with the exception of a negative control where equal volume of 1×PBS was added. Cells were pulsed at 550 V, 40 μsec, 1 pulse using Multiporator (eppendorf). After pulsing cells were incubated at 37° C. for 10 min before transferring the cells to 5 ml of growth media. Cells were centrifuged at 800 rpm for 10 min and then resuspended in 12 ml of growth medium and flasked in T75 (BD, India). Twenty four hours post transfection cells were selected with 1 mg/ml G418.
Flow Cytometry Analysis
[0050] All data presented were gathered on BD™ LSR II Flow cytometer, tuned to Blue Laser (488 nm Excitation Wave Length). Data was analyzed on High Performance BD FACSDiva Software. Forward and Side-Scatter light gating were used to identify viable population whilst doublets were excluded using forward angle and pulse-width scatter gating. Analysis was maintained at an event rate not exceeding 600 cells per second and a total of 25,000 events were acquired per sample.
Single Cell Cloning By Limiting Dilution Method
[0051] Stable clones were routinely isolated by limiting dilution method. On the day of plating cell count was performed and cell were diluted to 5 cells/ml in growth media and plating at 200 ul/well. Plates were then incubated in 37° C. incubator for 15 days. Well with single clones were marked by observing under microscope for further use.
Fed-Batch Study for Monoclonal Antibody Productivity
[0052] Fed-Batch Study was performed in 250 ml shake flask. On day 0 cells were centrifuged and resuspended at 5×10 5 cells/ml in Power CHO2 Media. Flask was incubated in 37° C. incubator with shaking. 1 ml of culture was collected very 24 hr to determine cell count and antibody productivity.
[0053] Referring to FIG. 4A-4C are figures showing construction of pUB-CE-100-N Plasmid. pUB-CE-100-N was constructed by ligating BamHI and BgIII fragment (2084 bp) of pUB-GFP plasmid with BamHI fragment (1506 bp) of pMK-RQ-CE100-N plasmid grown in JM109.
[0054] Referring to FIG. 5A-5C are figures showing construction of pUB-CE-100-N-GFP. pUB-CE-100-N-GFP was constructed by ligating BgIII and NotI fragment(3549 bp) of pUB-CE-100-N with BgIII and NotI fragment (1540 bp) of pUB-GFP.
[0055] Referring to FIG. 6 is a graph showing comparison of expression between different vectors containing synthetic intron varying in size from 500 to 6000 base pairs.
[0056] Referring to FIG. 7 is a figure showing transient expression assay to test the functionality of pUB-CE-100-N-GFP plasmid.
[0057] Referring to FIG. 8A and 8B are graphs showing comparison of GFP expression between CHOK1 cells stably transfected with pUB-GFP and pUB-CE-100-N-GFP.
[0000]
TABLE 1
Oligo Name
Oligo Sequence (5′ to 3′)
500-F
atgagggggatgctgcccct
500-R
caggccggggtgatgaggta
SI-500-F
acgcgtgggtgagtctctagagatgagggggatgctgccc
ct
SI-500-R
gtcgacgagctgtaggaaaaagaagaaggcatgcaggccg
gggtgatgaggta
SI-1000-R
gtcgacgagctgtaggaaaaagaagaaggcatgggtggac
ccggccccccctg
SI-2000-R
gtcgacgagctgtaggaaaaagaagaaggcatgaagttga
tggtcttggccgc
SI-4000-R
gtcgacgagctgtaggaaaaagaagaaggcatggatctgg
gtccaacttacc
SI-6000-R
gtcgacgagctgtaggaaaaagaagaaggcatgttaacat
gaccttttacatgg
[0058] Plasmids with varying lengths of synthetic intron's (pUB-SI-500-GFP, pUB-SI-1000-GFP, pUB-SI-2000-GFP, pUB-SI-4000-GFP, pUB-SI-6000-GFP) were constructed by PCR amplification using Forward primer carrying Sequence for Splice Donor and Reverse primer carrying sequence for Splice Acceptor (Table-1). PCR amplified fragment were cloned into pGEM-T easy vector and then sub cloned into pUB-GFP plasmid using SaII and mluI restriction ends. For the construction of pUB-500-GFP PCR amplification was carried out with Splice Donor and Acceptor sites on the oligos.
EXAMPLE 1
Analysis of Intron Function with Respect To Size
[0059] A series of expression vectors (pUB-SI-500-GFP, pUB-SI-1000-GFP, pUB-SI-2000-GFP , pUB-SI-4000-GFP , pUB-SI-6000-GFP) as shown in HG 3A to 3G were constructed to demonstrate the effect of size of intron on splicing. Synthetic introns (SI-500, SI-1000, SI-2000, SI-4000, SI-6000) were constructed by. PCR amplification of Taq DNA coding sequences with Forward and Reverse Primers having minimal splice donor and minimal splice acceptor sequences of Beta-Globin Large Intron Sequence. A plasmid (pUB-500-GFP) with 500 by fragment with out splice donor and splice acceptor sequence was also constructed to have a control for expression in the absence of splicing.
[0060] The expression vectors pUB-GFP, pUB-500-GFP, pUB-SI-500-GFP, pUB-SI-1000-GFP, pUB-SI-2000-GFP , pUB-SI-4000-GFP , pUB-SI-6000-GFP ( FIG. 3 ) were transfected in to CHOK1 cells using Lipofectamine 2000° . Forty eight hours post transfection cell were analyzed for GFP expression using BD™ LSR II Flow cytometer. The mean GFP expression and % GFP expressing cells were compared and were as shown in FIG. 6 .
[0061] All the Synthetic Intron containing plasmids showed GFP expression following transient transfection. pUB-500-GFP didn't show any GFP expressing cells indicating that the expression from synthetic intron containing plasmids is due to splicing. However, the mean GFP expression and % GFP expressing cells decreased with increase in the size of the synthetic intron. The decrease in the mean GFP and % GFP expressing cells with increase in size of synthetic intron could be due to the size of the plasmid. Size of plasmid is known to affect transient transfection efficiency.
[0062] The above experiment had demonstrated that the Minimal Synthetic Donor Sequence and Minimal Synthetic Accepter Sequence can accommodate upto 6000 by sequence.
EXAMPLE 2
Transient Expression Assay to Test Expression of GFP from Secondary Transcriptional Unit Cloned in the Intron of Primary Transcriptional Unit
[0063] To test functionality of secondary transcriptional unit, CMV-GFP was cloned in the 5′ intron of primary transcriptional unit which encodes for Neomycin Resistance Gene ( FIG. 5C ). To test the expression of GFP, pUB-CE-100-N-GFP was transfected in to CHOK1 cells using Lipofectamine method. Forty eight hours post transfection GFP expressing cells were analyzed by Fluorescent microscopy. pUB-GFP (positive control) ( FIG. 7C 1 and C2) and pUB-CE-100-N (negative control) ( FIG. 7A 1 and A2 were used as controls in the experiment. Presence of GFP expression in pUB-CE-100-N-GFP transfected cells as shown in FIG. 7B 1 and B2 indicated that the positioning of the secondary transcriptional unit in the intron of primary transcriptional unit didn't affect the expression of GFR
EXAMPLE 3
Analysis of Functionality of Primary and Secondary Transcriptional Unit'S Following Stable Transfection
[0064] Primary transcriptional unit is often antibiotic selectable marker gene which was under the control of inducible metallothionein promoter and Secondary transcriptional unit is often Polypeptide of Interest which is under the control of a constitutive CMV promoter. The use of inducible promoter will help to switch off expression of neomycin resistance gene after selection. To test the functionality of both the primary and secondary transcriptional unit's pUB-CE-100-N-GFP was transfected in to CHOK1 cells using electroporation. Expression of Neomycin resistance gene was induced with 25 nm ZnSo 4 immediately after transfection. Twenty four hours post transfection cells were selected with 1 mg/ml G418. Fifteen days post transfection and selection, G418 resistant cells were analyzed for GFP expression using BD TM LSR II Flow cytometer. pUB-GFP (control for expression of neomycin and GFP) and pUB-CE-100-N (control for expression of neomycin resistance gene) were also transfected in to CHOK1 cells and selected with 1 mg/ml G418.
[0065] All the plasmids (pUB-GFR pUB-CE-100-N, pUB-CE-100-N-GFP) gave rise to G418 resistant colonies following selection indicating the presence of expression of neomycin resistance gene in all the transfectants. However, the efficiency of stable integration was found to be more in pUB-GFP compared to pUB-CE-100-N and pUB-CE-100-N was found to be more compared to pUB-CE-100-N-GFP (Table 2). The decrease in the number of G418 resistant colonies in pUB-CE-100-N-CMV-GFP could be due to the positioning of secondary transcriptional unit (CMV-GFP) in intron of primary transcriptional unit, (neomycin resistance gene). The possible reasons could be read through transcription and promoter occlusion.
[0000]
TABLE 2
Number of G418 Resistant Colonies Found 15 Days Post
Transfection and Selection
No. of G418 Resistant
Colonies following
Sample
Selection
CHOK1 Transfected with No Plasmid
0
CHOK1 Transfected with pUB-GFP
1.42
CHOK1 Transfected with pUB-CE-100-N
67
CHOK1 Transfected with pUB-CE-100-N-GFP
23
[0066] Fifteen days post transfection and selection stable pools were analyzed for GFP expression using BD™ LSR II Flow cytometer. Mean GFP and % expressing cells were compared between pUB-GFP, pUB-CE-100-N and pUB-CE-100-N-GFP. pUB-CE-100-N-GFP showed 0.3 fold higher mean GFP expression and 5 fold high %GFP expressing cells compared to pUB-GFP ( FIG. 8 ). The possibility of auto fluorescence was ruled out with the lack of GFP expression in untransfected samples and pUB-CE-100-N transfected samples. The presence of high mean GFP expression and % GFP expression cells in pUB-CE-100-N-GFP could be due to better selection.
[0067] The above experimentation had demonstrated that position of secondary transcriptional unit (GFP) in the intron of primary transcriptional unit (neomycin resistance gene) had affected the expression of neomycin resistance gene but not the GFP gene. The design further helped in the generation high expressing stable pool compared to normal plasmid. The high expressing pool will further help in the quick isolation of high expressing cell line.
EXAMPLE 4
Comparison of GFP Expressing Stable Pool and Clone Generated Using pUB-CE-100-N-GFP
[0068] pUB-CE-100-N-GFP with its unique design and stringent selection conditions results in high expressing stable pool that resembles that of clone. To compare Mean GFP expression and % expressing population between clone and pools stable transfection was repeated as in Example 3. Twenty four hours post transfection cells were selected at 1 mg/ml in G418 in T75 flask to generate stable pool and 96 well plate to generate stable clones. Fifteen days post selection, G418 resistant pool and clones were analysed for GFP expression using BD™ LSR II Flow Cytometer.
[0069] pUB-CE-100-N-GFP stable pools resemble that of clone with respect to mean GFP expression and % GFP expression population ( FIG. 9 ). In order to test the stability of pool, the pool was cultures for 30 days in the absence of selection. Stable pool were found .to be quiet stable for more than 30 days with respect to % GFP expression population. However, there is a slight drop in mean GFP expression.
[0070] High % GFP expression cell, High mean GFP and High stability makes pUB-CE-100-N-GFP stable pools ideal for scale up to bioreactor early in drug development for pre-clinical material generation.
EXAMPLE 5
Fed Batch Study of Antibody Producing Clone Generated Using pUB-CE-100-N-Ab-Lc and pUB-CE-100-H-Ab-Hc Plasmids
[0071] Antibody productivity by the vector system of the invention was tested by co-transfection of light chain and heavy chain plasmids wherein the light chain was placed in the intron of neomycin resistance gene in pUB-CE-100-N-Ab-Lc ( FIG. 10 ) and heavy chain plasmid was placed in the intron of hygromycin resistance gene in pUB-CE-100-H-Ab-Hc ( FIG. 10 ). To test the efficiency of the expression vector of the invention pUB-CE-100-N-Ab-Lc and pUB-CE-100-H-Ab-Hc were co-transfected into CHOK1 cells using electroporation. Expression of Neomycin Resistance Gene and Hygromycin Resistance Gene were induced with 25 nm ZnSo4 immediately after transfection. Twenty four hours post transfection cells were selected with 1 mg/ml G418 and 200 ug/ml Hygromycin. Fifteen days post transfection and selection G418 and Hygromycin resistant cells were analyzed for antibody productivity and cell were plated in 96 well plate for isolation of clones. 15-20 days post plating clones were analyzed for productivity and one best clone was picked for Fed-Batch study.
[0072] Monoclonal antibody productivity was analyzed in Fed-Batch mode which is often the method of choice for antibody production. Fed batch study was carried out in 250 ml shake flaks. Antibody producing clone was seeded at 5×10 5 cells/ml in 70 ml of Power CHO2 media. Culture was fed with Cell Boost 5 at 5% volume on day 3 rd , 5 th , 7 th and 7 th . Samples were collected every 24 hr to determine cell count (Haemocytomer) and antibody productivity (ELISA). Cell density and antibody productivity were plotted and were shown in FIG. 11 . From the data it was clear that antibody producing clone had displayed a maximum cell density of 6.64×10 6 cells/ml and a maximum productivity of 911 mg/L.
[0073] Also, those skilled in the art can appreciate from the foregoing description that the present invention can be implemented in the variety of forms. Therefore, while the embodiments of this invention have been described in connection with particular examples thereof, the true scope of the embodiments of the invention should not be so limited since other modifications will be apparent to the skilled practitioner upon a study of the drawings and following claims.
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Methods and constructs for expressing biologically active proteins in eukaryotic cells are disclosed. A method for producing a non-conventional expression vector for production of biologically active compounds comprising a primary transcriptional unit and one or more secondary transcriptional units, a primary transcriptional unit encoding promoter, synthetic intron, selectable marker gene and polyadenylation signal or transcriptional terminator and a second transcriptional unit encoding promoter and polypeptide of interest surrounded by insulator sequences and placed in the intron of primary transcriptional unit. The synthetic intron disclosed is positioned at the 5′ end of the coding sequence and the synthetic intron capable for accommodating secondary transcriptional unit with base pairs ranging from 500 to 6000 and more.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical disc which is subjected to a sampled servo type tracking and its driving apparatus, particularly, it relates to improvements of the pit configuration for sampled servo preformatted in the optical disc.
2. Description of the Prior Art
FIG. 1 shows a track sector format of a conventional optical disc described in SPIE, vol. 695, Optical Mass Data Storage 2 (1986), Page 112. In the figure, (90) indicates a sector structure per one round of track comprising 32 sectors (#0 to #31). (91) shows a block structure per one sector comprising 43 blocks (B1 to B43). Each block is consisting of a 2-byte servo field and a successive 16-byte data field and being divided into 32×43=1376 blocks per one track. FIG. 2 shows a pit pattern of the servo field. Pits (92), (94) and (93), (94) are slightly deviated respectively in the opposite direction relative to axes of the track centers (97), (98). Tracking sensor signal can be obtained only from these pairs of pits (called a pair of wobbled pits). Such a servo system is called a sampled servo type whose operation principle is described, for example, in SPIE, Vol. 529, Third International Conference on Optical Mass Data Storage (1985), Page 140, so that it will be omitted here. In such prior art optical disc system, since the tracking sensor signal can be obtained only from the pair of pits in the servo field, guide grooves for tracking are not necessary. Accordingly, in order to access quickly from the present track to a certain object track, as shown in FIG. 2, the servo field structures A, B are arranged alternately at every 16 tracks so that the track quantity passed during the high speed access can be counted. In FIG. 2, the track number is given as follows,
track number=I+(N-1)×16
where, I=1, 2, 3 . . . 16. In the servo field structure A, N=1,3,5, . . . , and in the servo field structure B, N=2,4,6, . . . . In the servo field structures A and B, the position of one pit (92) of a pair of pits is shifted toward the track from the other pit (93). When accessing as crossing the track diagonally, the track quantity crossed can be obtained by detecting the positions of pits as illustrated in FIG. 3. In the figure, (71) indicates track centers which are present in a number at 1.5 μm intervals. (72) denotes the position of the servo field which is, as shown on the right hand side of the figure, constructed as A, B for every 16 tracks. (73) generally represents a locus of an optical spot at high-speed accessing. A black spot indicated at (74) shows the intersection of the optical spot and the servo field. The servo field structure can be recognized by the black spot (74). (99) denotes a recognized signal wave form, in which an "H" level represents the servo field structure A and an "L" level represents the servo field structure B. It is to be noted that 16 tracks are counted at every change of state of the signal wave form (99), from which the number of tracks crossed during accessing can be counted and the object track can be reached immediately.
In the prior art aforementioned, through it is possible to count the tracks when an optical head is accessed at high speed, as it is clear from FIG. 3, there is such a disadvantage that it can not be detected that whether the optical spot is processing externally or internally with respect to the disc track. As a method for accessing the optical head at high speed, there is the method of taking out the speed detecting signal during accessing from the disc to control the speed of the optical head. This speed control method, when compared to the conventional method in which a glass scale is provided at the outer portion to control the speed thereby, has such advantages as eliminating the glass scale, reducing the unit size and moderating the machine accuracy. However, when using the conventional optical disc and employing this speed control method, it will be a fatal defect that the direction can not be detected. It is because that, since the seek direction of the optical head which may reverse during the speed control can not be detected, the control loop makes a positive feedback causing the optical head to runaway and collide with an inner or outer stopper to break.
In the aforesaid prior art, through the tracks can be counted up to the high seek speed of 16×track pitch (1.5 μm)/block period (1/30×1/1376 sec.)=1.0 m/sec. at disc revolutions of 1800 r.p.m., as the servo field structure is changed at every 16 tracks, on the other hand, a fine count under 16 tracks is not possible. Therefore, when the remained track quantity approaches to 16, the other low speed track count technique must be used, greatly hindering the reduction of access time due to the low speed. The low speed track count technique as referred to herein is a method for counting from the number of tracks crossed by the tracking sensor signal of the sampled servo as the maximum detecting limit speed of track pitch/block period=61.9 mm/sec.
Furthermore, when controlling the speed by taking out the speed detecting signal from the disc during accessing, since the speed signal can be detected only after moving by 16 tracks, and idle time of a speed detector is lengthened and a speed control system becomes unstable, making the wide-band high-speed speed control impossible.
SUMMARY OF THE INVENTION
The present invention has been devised to solve the aforesaid problems, therefore, it is a primary object of the present invention to provide an optical disc and its driving apparatus capable of detecting the seek direction and speed of an optical head when seeking an object track, by dividing a sector block of the optical disc into two parts and preformatting pits whose positions are displaced respectively in a predetermined order.
It is another object of the present invention to provide an optical disc and its driving apparatus capable of detecting the seek direction and speed of an optical head as well as controlling the seek speed thereof when seeking an object track, by preformatting wobbled pits of a pattern in which a code having two significant digits in K digits is repeated every N tracks cyclically, and the significant digit of either of adjoining tracks is shifted by one digit.
It is a further object of the present invention to provide an optical disc and its driving apparatus capable of detecting the seek direction and speed of an optical head as well as controlling the seek speed thereof when seeking an object track, by preformatting address pits of a pattern in which a code having two significant digits in K digits is repeated every N tracks cyclically, and the significant digit of either of adjoining tracks is shifted by one digit.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory view showing a track sector format of a conventional optical disc,
FIG. 2 is a pit pattern configuration diagram of a conventional optical disc,
FIG. 3 is an explanatory view showing a servo field structure of a conventional optical disc, and a state of the disc surface being scanned by an optical spot,
FIGS. 4(a) and 4(b) are pattern configuration diagrams showing a first embodiment of a pit pattern of an optical disc of the first invention,
FIGS. 4(c) and 4(d) are pattern configuration diagrams showing a second embodiment of a pit pattern of an optical disc of the first invention,
FIG. 5 is an explanatory view showing a servo field structure of an optical disc of the first invention and a state of the disc surface being scanned by an optical spot,
FIG. 6 is a block diagram showing an embodiment of an optical disc driving apparatus of the second invention,
FIG. 7(a) is a pattern configuration diagram showing a first embodiment of a pit pattern of an optical disc of the third invention,
FIGS. 7(b) and (c) are pit pattern configuration diagrams showing second and third embodiments of a pit pattern of an optical disc of the third invention,
FIG. 8 is a block diagram showing one embodiment of an optical disc driving apparatus of the fourth invention,
FIGS. 9(a), 9(b), 9(c) and 9(d) are explanatory views of examples of pit pattern and regenerated signal,
FIG. 10 is an explanatory view of a code configuration of a pit pattern of an optical disc of the present invention,
FIG. 11 is the number of codes of a pit pattern of an optical disc of the present invention,
FIG. 12 is a circuit diagram showing a specific embodiment of a wobbled pit pattern detector shown in FIG. 8,
FIGS. 13(a), 13(b), 13(c), 13(d), 13(e), 13(f), 13(g), 13(h), 13(i), 13(j), 13(k), 13(l) and 13(m) are wave form diagrams for explaining the operation shown in FIG. 12,
FIG. 14(a) is a pattern configuration diagram showing a first embodiment of a pit pattern of an optical disc of the fifth invention,
FIG. 14(b) is a pattern configuration diagram showing a second embodiment of a pit pattern of an optical disc of the fifth invention,
FIGS. 14(c) and (d) are pit pattern code configuration diagrams showing third and fourth embodiments of a pit pattern code configuration of an optical disc of the fifth invention,
FIG. 15 is a block diagram showing one embodiment of an optical disc driving apparatus of the sixth invention,
FIGS. 16(a), 16(b), 16(c) and 16(d) are explanatory views of examples of pit pattern and regenerated signal,
FIG. 17 is an explanatory view of a code configuration of a pit pattern of an optical disc of the fifth invention,
FIG. 18 is the number of codes of a pit pattern of an optical disc of the fifth invention,
FIG. 19 is a circuit diagram showing a specific embodiment of an address pit pattern detector of FIG. 15, and
FIGS. 20(a), 20(b), 20(c), 20(d), 20(e), 20(f), 20(g), 20(h), 20(i), 20(j), 20(k), 20(l) and 20(m) are wave form diagrams for explaining the operation shown in FIG. 19.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 4(a) and 4(b) show a first embodiment of an optical disc of the first invention, in which even and odd servo field pit patterns are shown. In the FIGS. (1), (2), (3) and (4) of the even servo field and (6), (7), (8) and (9) of the odd servo field constitute pairs of wobbled pits, and in the same way as the prior art, respective pits are slightly deviated from the track center axes. Clock pits (5), (10) are arranged on the track center axes and serve as the clock reference of recorded information data as well as the sampling pulse generating reference of the wobbled pits. Assume that the timing positions on the basis of clock pits (5) and (10) of the wobbled pits (1) and (6), (2) and (7), (3) and (8), (4) and (9) are respectively a, b, c, d, and as shown in the figures, that the servo field structure having the pit at the timing position a is A or α, and similarly at b is B or β, at c is C or γ and at d is D or δ.
FIG. 5 is a view showing the arrangement of servo field patterns shown in FIGS. 4(a) and 4(b) on the disc surface. The numeral (20) indicates the even servo field, (21) denotes the odd servo field and (22) represents a data field. (23) is an even block, (24) is an odd block and (25) is a basic block, which is a basic unit including the even and odd blocks (23), (24) and corresponds to one block of the conventional example shown in FIG. 1. That is, as same as the even block and odd block, the block length is one half of that of the conventional block. (26), (27) indicate loci of the optical disc spot during accessing.
FIG. 6 shows one embodiment of an optical disc driving apparatus of the second invention. The numeral (30) denotes an optical disc of the first invention, underside of which is opposed by an optical head (31) which is movable radially of the optical disc (30) for recording and regenerating information therefrom. (32) is an optical detector for detecting information from the optical disc (30), and the detected information is given to a pre-amplifier (33) which is connected to the optical detector (32) and converts the current into the voltage. The output signal from the pre-amplifier (33) is given respectively to an even-odd field discriminating circuit (34) and a pit location discriminating circuit (35), and respective discriminated results are given to a speed detecting circuit (36) which detects the radial speed and seek direction of the optical head (31) relative to the optical disc (30). (37) denotes a speed control circuit for controlling the speed of the optical head (31) by the output of the speed detecting circuit (36) to access an object track.
In the following, operations of an optical disc of the first invention and an optical disc driving apparatus of the second invention will be described together.
As shown in FIG. 5, since a pair of wobbled pits are detected naturally by a pair of even and odd servo fields to give the tracking sensor signal, it will be omitted.
FIG. 5 shows the state of the servo field structure arranged on the disc surface being scanned by an optical spot. In the same way as FIG. 3, tracks are aligned at 1.5 μm pitches and the numeral (26) or (27) represents a locus of the optical spot accessing at high speed. In FIG. 5, as shown in the figure, the servo field structure is an iterative structure of AABBCCDD for every 3 tracks in the even servo field, and in the odd servo field, it is an iterative structure of ααββγγδδ by offsetting 3 tracks with respect to the even servo field. The track locus (26) shows the case wherein the optical spot is moving upwardly in the figure at maximum detectable speed, detecting C at a black spot (28) and δ at a block point (29) in the odd field which is the next servo field. In FIG. 6, for example, from the sector header signal of the signal which has been detected from the disc and converted into the electric signal by the pre-amplifier (33), whether the field is even field or odd one is discriminated by the even-odd field discriminating circuit (34). In the pit location discriminating circuit (35), the reflected signal level from the disc is sampled by the sampling signal of the timing locations a, b, c, d made from the clock pit to discriminate the pit location by obtaining the timing location in which a maximum signal level can be obtained. It is to be understood that ABCD αβγδ can be specified by the pit location and whether the field is even field or odd one. In FIG. 5, the radial seek speed of the spot locus (26) is represented by, block seek speed ×tan θ. The spot locus (27) shows the case wherein the optical spot is moving downwardly at maximum speed, and in this case, α is detected after C. The seek speed in this case is represented by, block seek speed ×tan (θ). All cases are involved within ±θ. The upper limit speed, 1.5 μm×9/(1/30×1/1376×1/2)=1.1 m/sec., is approximately as same as the conventional one. When the speed is below this value, it falls within one period from α to δ in the next servo field starting from C, so that the location is decided uniquely as well as the seek direction. In the speed detecting circuit (36), for example, if α appears after C, the speed is detected as the one to have moved 3 tracks upward in the block seek time. When the optical head (31) moves to the even servo field from the odd servo field, for example, if D appears after γ, the speed is detected as the one to have moved 3 tracks upward in the block seek time. The speed signal thus detected is compared with the speed reference signal which changes responsive to the remaining number of tracks by the speed control circuit (37) to control the access speed of the optical head (31) so as to correspond to the speed reference.
Though the speed can be detected only at every 16 tracks in the conventional optical disc, since the arrangement of servo patterns is decided independently in the even and odd servo fields respectively as is the case of the embodiment aforementioned, a very fine speed detection is possible, and as it will be apparent from FIG. 5, since the speed is detected at every 3 tracks, an idle time of the speed detecting circuit can be shortened and stability of the speed control system is increased. Also, the track count is possible for every 3 tracks, enabling the fine counting. Since the speed detecting circuit is for substantially detecting the speed and seek direction, the speed control system never becomes a positive feedback and the stable control is possible even when the accessing direction is reversed during the speed control.
In the optical disc of the aforesaid embodiment of the first embodiment, though various servo field patterns were constructed by shifting the location of wobbled pits, as shown in FIGS. 4(c) and 4(d), the servo field pattern may be constructed by arranging not the wobbled pits (1), (6) to (4), (9), but the independent access pits (5), (10) for access control periodically on a plurality of access pit locations a, b, c, d on the track center axes. The access pit may be pluralized and coded. In the case of FIGS. 4(c) and 4(d), it is also possible for the wobbled pits (1), (6) to (4), (9) to function commonly as the reference pits for timing. In the servo field structure shown in FIG. 5, though the 3-track offset was provided in the cyclic structure of the even and odd servo fields, it is not inevitable.
Likewise, though the number of timing positions was described as four, it is not limited thereto, any number above two will do as the seek direction can be detected if it is more than two. The more the number is, the more increases the maximum detecting speed. The number of tracks of the same servo pattern was also explained as three, but any number above one will do. The less the number is, the more increases the resolving-power, shortening the idle speed detecting time and increasing the stability.
In the embodiment aforementioned, through accessing the entire optical head has been explained, in the case of separate type optical head, it will be understood that it is also applicable when accessing a portion of optical head.
Furthermore, the optical disc comprising any of the following types will do, a write-once type, an erasable type including an magneto-optical disc and a read only type including a compact disc.
As described heretofore, in the optical disc of the first invention, it is possible to detect the direction during accessing as well as increasing the resolving-power of the track count. Moreover, in the optical disc driving apparatus of the second invention, it is possible to detect the speed and direction from the information track using the optical disc of the first invention to control the speed for accessing, and to make the apparatus smaller.
Next, the third invention will be described.
FIG. 7(a) is a view showing the first embodiment of an optical disc of the third invention, in which pit patterns of servo fields are shown. In the figure, (1) and (2) respectively constitutes pairs of wobbled pits, and as same as the prior art, the pits of respective pairs are deviated slightly from the track center axes. Wobbled pit patterns of respective tracks are represented by a code Dn (n=1 to 18) indicated at {A(n,1), A(n,2) . . . A(n10)}, and the digit location of the wobbled pits of each Dn shows logic "1". Recording and regenerating clocks, as same as the prior art, generate clocks synchronizing with respective digits by a PLL (Phase Locked Loop) circuit by using the detect signal of the clock pits (3) generated at a constant period as the comparison signal. In the figure, the code Dn changes at every track and becomes a cyclic code at every 18 tracks. In each Dn, in the digits of A(n,1) to A(n,5) and A(n,6) to A(n,10), "1" is present by one and "0" digit therebetween is present by three or more. As features of Dn+1 and Dn-1 adjacent to Dn, one "1" digit is in the same location and the other "1" digit is in the location shifted by 1 bit. In FIG. 7(b), the number of composing digits of Dn is 12, and it is in such a pattern that, in each Dn, "1" is always present by one in the first 6 bits and the latter 6 bits. In this case, the number of patterns is 28. FIG. 7(c) shows another example wherein the composing digits are 12.
FIG. 8 shows one embodiment of an optical disc driving apparatus of the fourth invention. The numeral (30) indicates an optical disc of the third invention, underside of which is opposed by an optical head (31) which is movable radially of the optical disc (30) to record and regenerate information therefrom. (32) is an optical detector for detecting information from the optical disc (30), and the detected information is given to a pre-amplifier (33) connected to the optical detector (32) and converting the current into the voltage. The output signal from the pre-amplifier (33) is given to a wobbled pit pattern detector (40), and the output signal of the pattern detector is given to a speed detecting circuit (36a) for detecting the radial speed of the optical head (31) relative to the optical disc (30) from the relative track address information detected by the pattern detector (40), and a direction detecting circuit (36b) for detecting similarly the radial seek direction (internally or externally) of the optical head (31) relative to the optical disc (30) from the relative track address information. The output of the direction detecting circuit (36b) is given to a switch (42) for switching the signal which is to be transferred to the following step by the output porality of a reversing amplifier circuit (41) and the direction detecting circuit (36b), to the output signal of the speed detecting circuit (36a) or to the output signal of the reversing amplifier circuit (41). The numeral (37) generally indicates a speed control circuit for controlling the speed of the optical head (31) by the output of the switch (42) to access to an object track.
In FIGS. 9, 10 and 11, a composing method and features of a code Dn which is the basis of the third invention will be described. FIG. 9 shows wobbled pits and its regenerating wave forms. FIG. 9(a) shows wobbled pits whose pattern involves features of the code of the third invention. As the necessary condition for the wobbled pit, when the optical head tracks the normal track center, in respective wobbled-pit locations, as the prior art shown in FIG. 1, the track center numbers are recognized and the absolute track address is known. Therefore, the wobbled pit pattern arranged uniquely for the absolute track address can be known and the change of wobbled pit pattern at every track is not inconvenient in any way. Even when the absolute track address is not known, tracking error information can be obtained by converting the regenerated signal in the wobbled pit area into the digital value at respective digit locations by an A/D converter and comparing its upper two sample values. In FIG. 9(a), the regenerated signal of the track n becomes like the signal depicted in FIG. 9(b) and that of the track n+1 becomes like the signal depicted in FIG. 9(d). In the tracking servo, when regenerating the track n, at respective digit locations of A(n,2) and A(n,7), the signal amplitude is obtained by the A/D converter and the tracking servo system may be controlled so as to bring the amplitude values of the two signals equal. On the other hand, during accessing, the optical head passes on the different loci as (50), (60) and (70). When the locus of the optical head is (60), the regenerated signal becomes like the signal depicted in FIG. 9(c). Also in this case, the digit location of "1" in respective Dn patterns must be known. When detecting on the basis of the regenerated signal, in a code arrangement using the code of the third invention, the regenerated signal is subjected to A/D conversion at respective digit locations on the basis of the basis of the adjacent code features to discriminate the two samples as "1" from its maximum value. By this method, when the wave form is as depicted in FIG. 9(c), its discriminating code is discriminated as either the code Dn of the track n or the code Dn+1 of the track n+1, and its detecting capacity can be increased without depending upon the change of regenerated signal level etc. While, "1" of respective codes and the number of digits (run length) of "0" between "1" and "1" are R, the condition R≧3 is the value considering an intercode interference, and if the intercode interference is permissible, R may be made smaller.
Next, the cyclic frequencies N, when the digits of code Dn are K and aforesaid R is selected optionally, will be examined. FIG. 10 is an explanatory view and FIG. 11 shows one example thereof. Assume that A(n,i) and A(n,j) in the code Dn shown in FIG. 10(a) have logic "1". At this time, as shown in FIG. 10(b), a lattice of i, 1 to (K-R), and j, (r+1) to K, is considered, where (K-R)>2. The lattice outside the shaded portion is a pattern which satisfies run length≧R. A method of generating the code Dn of the third invention is the method, in which all routes starting from any lattice, moving to the lattice shifted in the direction i or j and finally returning to the first lattice position are permitted. However, the same lattice is not allowed to be passed twice. When K and R are given, maximum N is given by the maximum integral value satisfying the following equation. ##EQU1## where, K-R>2.
While, Dn is divided equally into the first digits and the latter digits, and the equally divided code in which "1" is present by one is considered. When using this code, the detecting capacity for disc defects etc. is improved more. FIG. 11 shows values which are obtainable by N. FIGS. 11(a) and (b) are the cases wherein R is 3 and 4, and FIGS. 11(c) and (d) are the values when the first half and second half of the Dn are conditioned to be set "1". While, logics for obtaining the relative track number n will be studied after the Dn pattern has been detected. A decoding process is basically possible by using a conversion ROM, but when the input address of the ROM is larger or when a gate array IC is used, hardwares become larger and not practical. The code of FIG. 7(b) is considered as one example of the third invention, and the track number n is obtained by the code sequence. In this case, Dn is given as,
Dn={A(n,1), A(n,2), . . . A(n,11), A(n,12)}. Dn is separated into,
Dn1={A(n,1), A(n,2), . . . A(n,6)}, and
Dn2={A(n,7), A(n,8), . . . A(n,12)}. Locations of digit "1" address in respective codes are at 0 to 5, and its address values are represented by binary 3 bits as follows.
V1=y0+2*y1+4*y2
V2=z0+2*z1+4*z2
Also, parameters are given as follows.
P0=y0
P1=y0*y1*y2
P2=y0*y1*y2
P3=y0*y1*y2
P4=y0*y1*y2
P5=y0*y1*y2
P6=z0*z1*z2
V1*=5-V1
V2*=5-V2
Address number n is represented by the following equation. ##EQU2##
FIG. 12 shows a specific embodiment of a wobbled pit pattern detector (40). FIG. 13 is an explanatory view of the wave form. In FIG. 13, the regenerated signal of FIG. 13(c) regenerated from the disc and converted into the voltage signal is inputted to an input terminal (116), and converted into the digital value by an A/D converter (101) at the sampling position of the input clock signal of FIG. 13(d) which is the signal produced from the aforesaid clock pit by a PLL circuit. The digital signal (117) is inputted to first half and second half code pattern detectors (114) and (115). To terminals (110) and (112), separation gate signals of FIGS. 13(e) and 13(f) for detection are inputted. Here, the first half code pattern detector (114) will be described. Now, assuming that the input signal digital value (117) is as shown in FIG. 13(g), the signal (118) value passing through an AND gate (102) becomes as shown in FIG. 13(h). Signals (118) and (119) are then inputted to a comparator (104) via a latching circuit (103). When the signal (118) value becomes larger than the signal (119), the comparator (104) outputs "H" which is to be latched and shifted to the signal (119). In this embodiment, the signal (119) value is as shown in FIG. 13(i). By the latch signal at this time, a one shot multivibrator (105) is driven and a pulse as shown in FIG. 13(j) is produced in its output (120). By this pulse of FIG. 13(j), a counter (106) is set at 4 digits of the pattern (in this case, it has 5 bits and takes the value of 0 to 4, so that 4 is taken), and the value is subtracted by the clock signal of FIG. 13(d) when the pulse is not produced. While, the gate signal of FIG. 13(e) is adapted to be cleared in the area "L", and when it is completed, the counter output signal (121) is latched by a latching circuit (107) and the output signal (122) value becomes 3 as (l), and is outputted to an output terminal (111) in the binary code 3 -bit signal. Similarly, also a code representing the second half pit location is outputted to an output terminal (113) as a value 2 at the timing signal of FIG. 13(m). This signal output is processed by an algorithmic logic circuit for obtaining the aforesaid track number to produce the relative track address in a binary code. The speed detector (36a) and the direction detecting circuit (36b) shown in FIG. 8, utilizing the change of relative track address during accessing, set its value. For example, the time between the servo sectors is known since the revolving rate is constant, thus the number of tracks passed is known by the difference of relative track address value at that time to calculate the seek distance. The speed can be obtained from the time and distance. It is also possible to find the direction by the change of relative track address value. These discriminations can be processed readily by a microcomputer. In the configuration shown in FIG. 8, when an optical spot or an optical head (31) moves externally, the output of the direction detecting circuit (36b) shows a "H" level and when moving internally, it shows a "L" level. By switching the switch (42) to the speed detecting circuit (36a) when the output polarity of the direction detecting circuit (36b) is at "H", and to the reversing amplifier circuit (41) when at "L", the analog input signal of the speed control circuit (37) becomes a signal having directional information to move, for example, externally when positive and internally when negative. Even when the direction is reversed during accessing in such a way, the speed control system never becomes a positive feedback, enabling the stable control. As described hereinabove, the following advantages are ensured by using the wobbled pit pattern of the third invention.
(1) A detecting capacity of the detecting pattern during accessing is high.
(2) Intercode interference of the detecting pattern is small.
(3) Decoding hardwares of the track number can be composed simply from the detecting pattern.
(4) Direction and speed detections can be effected every sample byte, thus more precise control is possible.
(5) By using 12 bits as the number of code bits of the wobbled pits, the relative track addresses of 28 to 32 can be produced to cope with the high-speed and low-speed seekings.
In the embodiment aforementioned, though the case wherein the entire optical head is accessed has been described, it is to be understood that it is also applicable when a portion of the optical head is accessed as in the case of a separate-type optical head. Any optical disc of a write once type, erasable type including an magneto-optical disc and a read only type including a compact disc will do.
As described heretofore, in the optical disc of the third invention, it is possible to detect the direction during accessing as well as improving the resolving-power of the track count.
Furthermore, in the optical disc driving apparatus of the fourth invention, it is possible to detect the seek speed and direction from the information track to control the speed for accessing using the optical disc of the third invention, and the apparatus can be made smaller.
Next, the fifth invention will be explained.
FIG. 14(a) shows a first embodiment of an optical disc of the fifth invention. In the figure, pit patterns of a servo field are shown, and in which (1) and (2) respectively constitute pairs of wobbled pits and as same as the prior art, the pits of respective pairs are deviated slightly from track center axes. (5) indicates clock pits and (3) and (4) are address pits. Address pit patterns in respective tracks can be represented by a code Dn (n=1 to 28) indicated at {A(n,1), A(n,2) . . . A(n,12)}, and the digit location of the address pits of each Dn shows logic "1". Recording and regenerating clocks, as same as the prior art, generate clocks synchronizing with respective digits by a PLL (Phase Locked Loop) circuit by using the detecting signal of the clock pits (3) generated at a constant period as the comparison signal. In the figure, the code Dn changes at every track and becomes a cyclic code at every 28 tracks. In each Dn, in the digits of A(n,1) to A(n,6) and A(n,7) to A(n,12), " 1" is present by one and "0" digit therebetween is present three or more. As features of Dn+1 and Dn-1 adjacent to Dn, one "1" digit is in the same location and the other "1" digit is in the location shifted by one bit. In FIG. 14(b), the clock pit location and address pit location are different. In FIG. 14(c), the number of composing digits of Dn is 10, and it is in such a pattern that in each Dn, "1" is always present by one in the first 5 bits and the latter 5 bits. In this case, the number of patterns is 18. FIG. 14(d) shows another example wherein the number of digits of the address pattern of the same composition is 12.
FIG. 15 shows one embodiment of an optical disc driving apparatus of the sixth invention. As the configuration is similar to those shown in FIG. 8, explanation will be omitted.
In FIGS. 16, 17 and 18, a composing method and features of a code Dn which is the basis of the present invention will be described. FIG. 16 shows address pits and its regenerated wave forms. FIG. 16(a) shows the address pits whose pattern involves feathers of the code of the present invention. In the regenerated signal of the address pit portion, the regenerated signal of the track n becomes as depicted in FIG. 16(b) and the regenerated signal of the track n+1 becomes as depicted in FIG. 16(d). During accessing, the optical head passes on the different loci as (50), (60) and (70). When the locus is (60), the regenerated signal becomes as shown in FIG. 16(c). In a code arrangement using the code of the present invention, the regenerated signal is subjected to A/D conversion at respective digit locations on the basis of the adjoining code features to discriminate the two samples as "1" from its maximum value. By this method, when the wave form is as shown in FIG. 16(c), not to mention of the forms depicted in FIGS. 16(b) and 16(d), its discriminating code is discriminated either as the code Dn of the track n or the code Dn+1 of the track n+1, and its detecting capacity can be increased without depending upon the change of regenerated signal level and so on. While, "1" of respective codes and the number of digits (run length) of "0" between "1" and "1" are R, the condition R≧3 is the value considering an intercode interference, and if the intercode interference is permissible, R may be made smaller.
Next, cyclic frequencies N will be examined when the digits of code Dn are K and aforesaid R is selected optionally. FIG. 17 is an explanatory view and FIG. 18 shows one embodiment thereof. Assume that A(n,i) and A(n,j) in the code Dn of FIG. 17(a) have logic "1". At this time, as shown in FIG. 17(b), a lattice of i, 1 to (K-R), and j, (r+1) to K, is taken into consideration, where (K-R)>2. The lattice outside the shaded portion is a pattern which satisfies run length≧R. A method of generating the code Dn of the present invention is the method, in which all routes starting from any lattice, moving to the lattice shifted in the direction i or j and finally returning to the first lattice position are permitted. However, the same lattice is not allowed to be passed twice. When K and R are given, maximum N is given by the maximum integral value satisfying the following equation. ##EQU3## where, K-R>2.
While, Dn is divided equally into the first digit and the latter digit, and the equally divided code in which "1" is present by one is taken into consideration. When using this code, the detecting capacity for disc defects etc. is improved more. FIG. 18 shows values which are obtainable by N. FIGS. 18(a) and (b) are the cases where R is 3 and 4, and FIG. 18(c) and (d) are the values when the first half and second half of the Dn are conditioned to be set "1". While, logics for obtaining the relative track number n will be studied after the Dn pattern have been detected. A decoding process is basically possible by using a conversion ROM, but when the input address of the ROM is larger or when a gate array IC and the like is used, hardwares become larger and not practical. The code of FIG. 14(a) is considered as one example of the present invention, and the track number n is obtained by the code sequence. In this case, Dn is given as,
Dn={A(n,1), A(n,2), . . . A(n,11), A(n,12)}. Dn is separated into,
Dn1={A(n,1), A(n,2), . . . A(n,6)}, and
Dn2={A(n,7), A(n,8), . . . A(n,12)}. Locations of digit "1" in respective codes are at 0 to 5, and its address values are represented by binary 3 bits as follows.
V1=y0+2*y1+4*y2
V2=z0+2*z1+4*z2
Also, parameters are given as follows.
P0=y0
P1=y0*y1*y2
P2=y0*y1*y2
P3=y0*y1*y2
P4=y0*y1*y2
P5=y0*y1*y2
P6=z0*z1*z2
V1*=5-V1
V2*=5-V2
Address number n is represented by the following equation. ##EQU4##
FIG. 19 shows a specific embodiment of an address pit pattern detector (40). FIG. 20 is an explanatory view of its wave form. In FIG. 20, the regenerated signal (c) regenerated from the disc and converted into the voltage signal is inputted to an input terminal (116), and converted into the digital value by an A/D converter (101) at the sampling position of the input clock (d) which is the signal produced from the aforesaid clock pit by a PLL circuit. The digital signal (117) is inputted to first half and second half code pattern detectors (114) and (115). To terminals (110) and (112), separation gate signals of FIGS. 20(e) and 20(f) for detection are inputted. Here, the first half code pattern detector (114) will be described. Now, assuming that the input signal digital value (117) is as shown in FIG. 20(g), the signal (118) value passing through an AND gates (102) becomes as shown in FIG. 20(h). Then, signals (118) and (119) are inputted to a comparator (104) via a latching circuit (103). When the signal value (118) becomes larger than the signal (119), the comparator (104) outputs "H", which is latched and shifted to the signal (119). In this embodiment, the signal value (119) is as shown in FIG. 20(i). By the latch signal at this time, a one shot multivibrator (105) is driven and a pulse as shown in FIG. 20(j) is produced in its output (120). By this pulse of FIG. 20(j), a counter (106) is set at 4 digits of the pattern (in this case, it has 5 bits and takes the value of 0 to 4, so that 4 is taken), and the value is subtracted by the clock signal of FIG. 20(d) when the pulse is not produced. While, the gate signal depicted in FIG. 20(e) is adapted to be cleared in the area "L", and when the separation gate signal of FIG. 20(e) is completed, the counter output signal (121) is latched by a latching circuit (107) and the output signal (122) value becomes 3 as shown in FIG. 20(1), and is outputted to an output terminal (111) in the binary code 3 bit signal. Similarly, also a code representing the second half pit location is outputted to the output terminal (111) as a value 2 at the timing point depicted in FIG. 20(m). This signal output is processed by an algorithmic logic circuit for obtaining the aforesaid track number to produce the relative track address in a binary code. The speed detector (36a) and direction detecting circuit (36b) of FIG. 15, utilizing the change of relative track address during accessing, set its value. For example, the time between the servo sectors is known as the revolving rate is constant, thus the number of track passed is known by the difference of relative track address value at that time to calculate the moving distance. The speed can be obtained from the time and distance. It is also possible to find the direction by the change of relative track address value. These discriminations can be processed readily by a microcomputer. In the configuration shown in FIG. 15, when an optical spot or an optical head (30) moves externally, the output of the direction detecting circuit (36b) shows an "H" level, and when moving internally, it shows an "L" level. By switching the switch (42) to the speed detecting circuit (36a) when the output polarity of the direction detecting circuit (36b) is at "H", and to the reversing amplifier circuit (41) when at "L", the analog input signal of the speed control circuit (37) becomes a signal having directional information to move, for example, externally when positive and internally when negative. Even when the direction is reversed during accessing in such a way, the speed control system never becomes a positive feedback, enabling the stable control.
Next, effects of the increased track density will be studied. It has been described already that if the track density is increased, the effects of the adjacent tracks are encountered. An embodiment of FIG. 14(a) will be taken into consideration as a pit pattern arrangement of the servo field of the present invention. In the wobbled pit and clock pit, pit locations of the adjoining tracks are in the same location, thus the unbalanced signal interference to respective pits does not occur as the prior art. Therefore, the tracking performance or detecting performance of the clock pit is not deteriorated. Though the detecting capacity during accessing is the problem for the address pit, as described in conjunction with FIG. 16, it will be apparent that its performance is not deteriorated.
As described heretofore, the following advantages are ensured by using the address pit pattern of the fifth invention.
(1) A detecting capacity of the detecting pattern during accessing is high.
(2) Intercode interference of the detecting pattern is small.
(3) Decoding hardwares of the track number can be composed simply from the detecting pattern.
(4) Direction and speed detections can be effected every sample byte, thus more precise control is possible.
(5) By using 12 bits as the number of code bits of the address pit, the relative track addresses of 28 to 32 can be produced to cope with the high-speed and low-speed seekings.
(6) Tracking and accessing performances are not deteriorated even when the track density is increased.
In the aforesaid embodiment, though the case wherein the entire optical head is accessed has been described, it is to be understood that it is also applicable when a portion of the optical head is accessed as in the case of a separate-type optical head. Any optical disc of a write once type, erasable type including an magneto-optical disc and a read only type including a compact disc will do.
As described hereinabove, in the optical disc of the first invention, it is possible to detect the direction during accessing as well as improving the resolving-power of the track count. In addition, the track density can be increased. Furthermore, in the optical disc driving apparatus of the second invention, it is possible to detect the speed and direction from the information track to control the speed for accessing using the optical disc of the first invention, and the apparatus can be made smaller.
As this invention may be embodied in several forms without departing from the spirit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the meets and bounds of the claims, or equivalence of such meets and bounds thereof are therefore intended to be embraced by the claims.
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A sampled servo type optical disc and its driving apparatus is disclosed, in which by cyclically repeating wobbled pits or address pits of the optical disc composed by two significant digits at every N tracks, and preformatting by patterns spaced in different intervals at every track, when the optical disc driving apparatus seeks an object track, the seek direction of the optical head can be detected by the sequence of change of the pattern, and its seek speed can be detected at high speed by the detected result of the pattern, ensuring the speed control of the optical head in response to the detected seek direction and speed.
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This application is a divisional application of U.S. patent application Ser. No. 11/251,837, filed Oct. 18, 2005 now U.S. Pat. No. 7,253,877.
FIELD OF THE INVENTION AND RELATED ART
This invention relates to an exposure apparatus and an exposure method usable in the manufacture of semiconductor devices, for example, for transferring a pattern onto a resist upon a substrate by exposure. In another aspect, the invention concerns a device manufacturing method that uses such an exposure apparatus or an exposure method.
A scanning exposure method (step-and-scan method) is now the main stream of exposure apparatuses, in which illumination light of a slit-like shape having a size approximately corresponding to the diameter of a circular imaging region of a projection optical system is used, and in which a reticle and a wafer are synchronously and scanningly moved thereby to enlarge the transfer region.
According to this method, as compared with a step-and-repeat method in which simultaneous exposure is carried out with respect to each transfer region by using a projection lens, if a projection optical system having an imaging region of the same size is used, a larger transfer region can be provided.
Japanese Laid-Open Patent Application, Publication No. 10-097989, shows this type of an exposure apparatus having blade means, which is provided as light blocking means to prevent irradiation of unnecessary shot regions with light, the blade means being moved in synchronism with the scan motion of a reticle and a wafer.
However, if the blade means is moved, a drive reaction force produced by moving the blade may be transmitted through a blade support to an illumination support system as an external disturbance. If it occurs, vibration may remain in the main frame of the exposure apparatus, which will, in turn, put vibratory external disturbance on the projection lens and/or the reticle stage. The precision of exposure may be degraded thereby.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide an improved exposure apparatus and/or an improved exposure method by which the inconvenience described above can be removed or reduced.
In accordance with an aspect of the present invention, there is provided an exposure apparatus for projecting, by exposure, a pattern of an original onto a substrate, the apparatus comprising light blocking means for blocking at least a portion of exposure light, driving means for moving the light blocking means, and reaction force absorbing means for absorbing a drive reaction force of the driving means, wherein the driving means includes a stator, and wherein the reaction force absorbing means absorbs the reaction force by moving the stator of the driving means.
With this structure of the present invention, adverse influence of vibratory external disturbance, to be caused by a drive reaction force as the blade of the light blocking system is driven, can be reduced significantly.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic and elevational view of a main portion of an exposure apparatus including an illumination system, according to an embodiment of the present invention.
FIG. 2 is a schematic view for explaining disposition of an illumination system and other components, according to an embodiment of the present invention.
FIG. 3 is a plan view of a scan masking blade unit according to an embodiment of the present invention.
FIG. 4 is a plan view of a scan masking blade unit according to another embodiment of the present invention.
FIG. 5 is a flow chart for explaining the procedure of device manufacturing processes, in an embodiment of the present invention.
FIG. 6 is a flow chart for explaining details of a wafer process, in an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described with reference to the attached drawings. Specifically, the invention will be described with reference to an example of a scan type exposure apparatus wherein an original is a reticle and a substrate is a wafer. FIGS. 1-6 show a few embodiments of the present invention.
Embodiment 1
FIG. 1 is a schematic and elevational view of a main portion of an exposure apparatus including an illumination system, according to an embodiment of the present invention. FIG. 2 illustrates the disposition of an illumination system, and the like, of the first embodiment.
Denoted in these drawings at 1 is an illumination system, which is a function for projecting an exposure light source and exposure light toward a reticle while shaping the light. Denoted at 1 A is an illumination system support base that functions to fixedly support the illumination system unit 1 with respect to a main frame 5 of the exposure apparatus. Denoted at 1 B is an illumination system light source introducing unit. Denoted in FIG. 2 at 1 C is an illumination system that includes the illumination system light source introducing unit 1 B.
Denoted at 2 is a reticle stage that carries thereon a reticle, which is an original of an exposure pattern. The reticle stage 2 is scanningly moved relative to a wafer at the ratio of reduction exposure magnification with respect to the wafer. Denoted at 3 is a projection lens for projecting the original pattern onto the wafer (substrate) in a reduced scale.
Denoted at 4 is a wafer stage. For individual exposures, the wafer stage functions to sequentially and successively move and position the substrate (wafer) with respect to the exposure position defined in relation to the reduction projection lens 3 . Denoted at 5 is the main frame of the exposure apparatus, and it supports the reticle stage 2 , the reduction projection lens 3 , the wafer stage 4 , and so on.
Denoted at 6 is a scan masking unit, which includes light blocking means for blocking light to the pattern of the reticle. The light blocking means comprises at least one plate-like member (hereinafter, a “blade”), which is disposed upon a plane being conjugate with the reticle surface.
In scanning exposure apparatuses, since the reticle and the wafer are scanningly moved, the blade member, such as described above, has to be moved as well, in synchronism with the reticle and wafer motion.
Referring to FIG. 3 , the scan masking unit according to this embodiment of the present invention will be explained in greater detail. The scan masking unit 6 includes an X scan masking unit 7 and a Y scan masking unit 8 . Denoted at 6 A and 6 B are Y blades, and these Y blades 6 A and 6 B are scanningly moved as well for scanning motion of the reticle, approximately in synchronism with the reticle scan motion. Denoted at 6 C and 6 D are X blades, and these X blades are moved in a direction orthogonal to the scanning movement direction of the Y blades 6 A and 6 B to thereby perform light blocking in the scan widthwise direction of the reticle.
Denoted at 7 is the X scan masking unit. Denoted at 7 A is a stator for an X linear motor that functions to move the X blades 6 C and 6 D in the X direction by use of X movable elements 7 C. Denoted at 7 B is an X linear encoder, which is provided to measure the position of the X blades 6 C and 6 D.
Denoted at 8 A is a stator for a Y linear motor that functions to move the Y blades 6 A and 6 B in the Y direction by use of Y movable elements 8 C. Denoted at 8 B is a Y linear encoder, which is provided to measure the position of the Y blades 6 A and 6 B.
There are self-weight compensating magnets 8 D as magnet means for compensating for the self weight of the Y linear motor. These magnets are provided with the same magnetic poles disposed opposed to each other, to enable the weight compensation without contact to each other. Denoted at 8 E are leaf springs that serve to provide resilient support between the illumination system base 1 A and the Y linear motor stator 8 A. Each leaf spring 8 E has one end fixed to the illumination system support base 1 A, so that they can resiliently support the Y linear motor stator 8 A movably in the thrust producing direction of the Y linear motor.
Denoted at 8 F is a stator position controlling motor, and it functions to control the movement position of the stator 8 A of the Y linear motor in the thrust direction thereof.
Within the structure described above, the Y blades 6 A and 6 B are scanningly moved, and a drive reaction force of the Y movable elements 8 C may be produced with respect to the Y linear motor stator 8 A. If this occurs, the stator 8 A of the Y linear motor moves in a direction of an arrow in the drawing, and it can function as a passive counter to absorb the drive reaction force.
Furthermore, the Y linear motor stator 8 A shifted as described above is stabilized and returning-position controlled by means of the stator position controlling motor 8 F. By this, the position of the Y linear motor stator 8 A can be stabilized and maintained at an approximately neutral position.
As a consequence of the above, no vibratory external disturbance is applied to the illumination system support base 1 A and, thus, there is no possibility of vibration remaining in the main frame 5 of the exposure apparatus. Therefore, transmission of vibratory external disturbance to the reduction projection lens 3 and the reticle stage 2 can be avoided, and degradation of exposure precision can be prevented.
Although the above-described structure is particularly effective in relation to a linear motor that drives a blade in the scan direction (Y direction), it still has an effect with respect to the X direction. This will be explained with reference to a second embodiment of the present invention.
Embodiment 2
FIG. 4 is a plan view of a scan masking blade unit in a second embodiment of the present invention. In the first embodiment described above, the absorbing means for absorbing the reaction force of the Y blades 6 A and 6 B comprises the leaf springs 8 E and the stator position controlling motor 8 F. In addition to these components, in the second embodiment of the present invention, as shown in FIG. 4 , there are leaf springs 7 E at positions corresponding to the opposite ends of the X linear motor stator 7 A and, also, there is a stator position controlling motor 7 F at one end side of the X linear motor stator 7 A.
Each leaf spring 7 E has an end fixed to the illumination system support base 1 A, so that they resiliently support the X linear motor stator 7 A movably in the thrust producing direction of the X linear motor. The stator position controlling motor 7 F functions to control the movement position of the stator 7 A of the X linear motor, with respect to the thrust direction thereof.
In accordance with this embodiment of the present invention as described above, as regards the Y blades 6 C and 6 D of the X liner motor stator 7 A, as well, as with the Y blades 6 A and 6 B, they function to resiliently support the X linear motor stator 7 A through the leaf springs 7 E and with respect to the drive reaction force producing direction. Also, with the provision of the stator position controlling motor 7 F, the drive reaction force of the X linear motor can be absorbed.
Embodiment 3
Next, referring to FIGS. 5 and 6 , an embodiment of a device manufacturing method, which uses an exposure apparatus described above, will be explained as a third embodiment of the present invention.
FIG. 5 is a flow chart for explaining a general procedure of manufacturing various microdevices, such as semiconductor chips, for example. Step 1 is a design process for designing a circuit of a semiconductor device. Step 2 is a process for making a mask on the basis of the circuit pattern design. Step 3 is a process for preparing a wafer by using a material such as silicon. Step 4 is a wafer process, which is called a pre-process, wherein, by using the thus prepared mask and wafer, a circuit is formed on the wafer in practice, in accordance with lithography. Step 5 , subsequent to this, is an assembling step, which is called a post-process, wherein the wafer, having been processing at step 4 , is formed into semiconductor chips. This step includes an assembling (dicing and bonding) process and a packaging (chip sealing) process. Step 6 is an inspection step wherein an operation check, a durability check, and so on, for the semiconductor devices produced by step 5 , are carried out. With these processes, semiconductor devices are produced, and they are shipped (step 7 ).
The wafer process at Step 4 may include the following steps, as shown in FIG. 6 . Step 11 is an oxidation process for oxidizing the surface of a wafer. Step 12 is a CVD process for forming an insulating film on the wafer surface. Step 13 is an electrode forming process for forming electrodes upon the wafer by vapor deposition. Step 14 is an ion implanting process for implanting ions to the wafer. Step 15 is a resist process for applying a resist (photosensitive material) to the wafer. Step 16 is an exposure process for printing, by exposure, the circuit pattern of the mask on the wafer through the exposure apparatus described above. Step 17 is a developing process for developing the exposed wafer. Step 18 is an etching process for removing portions other than the developed resist image. Step 19 is a resist separation process for separating the resist material remaining on the wafer after being subjected to the etching process. By repeating these processes, circuit patterns are superposedly formed on the wafer.
With these processes, high density microdevices can be manufactured.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application No. 2004-306054, filed Oct. 20, 2004, which is hereby incorporated by reference.
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An exposure apparatus for illuminating an original through an illumination system and for transferring a pattern of the original onto a substrate. The apparatus includes a movable element having a blade, the blade being provided in the illumination system and blocking at least a portion of illumination light, a stator configured to relatively move the movable element, and a resilient supporting member configured to resiliently support the stator without contacting the stator.
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[0001] This application claims benefit of the filing date of and priority under 35 U.S.C. § 119(e) to U.S. provisional patent application Ser. No. 60/429,502 filed Nov. 27, 2002, which is incorporated herein be reference.
BACKGROUND OF THE INVENTION
[0002] The present invention is directed to a submergence system. The invention can be employed in processes and apparatus for producing molten materials by electrolysis of their salts where the metal is lighter than the electrolyte. The invention can also be employed in processes and apparatus for producing molten materials not relying on electrolysis systems, one non-limiting example being a scrap submergence system.
[0003] Electrolytic cells for producing magnesium metal from MgCl 2 are well known and widely employed in present-day commercial practice. Typically, in such a cell, the MgCl 2 is dissolved in a molten salt electrolyte comprising a mixture of alkali metal and alkaline earth metal chlorides.
[0004] Magnesium metal deposits in molten state on cell cathode(s) and chlorine gas is generated at anode(s) within a cell chamber; since both the metal and the gas are lighter than the electrolyte, both migrate upwardly. The magnesium metal is transported to a locality outside the cell chamber for collection and periodic removal, while the chlorine gas is separately collected and withdrawn above the cell chamber.
[0005] As more specifically described in U.S. Pat. No. 5,439,563 (“the '563 patent”), which is incorporated herein by reference, an electrolytic cell can include a main chamber that holds molten salt electrolyte containing dissolved MgCl 2 . As free electrons are introduced to the molten salt electrolyte, which includes the MgCl 2 , the dissolved MgCl 2 reacts in the electrolytic cell to form molten magnesium and chlorine gas. Accordingly, to produce more molten magnesium the MgCl 2 must be replenished. A known way of replenishing the MgCl 2 is by introducing MgCl 2 particulates through a conduit that discharges the particulates into the molten salt electrolyte bath. As shown in the '563 patent, a vertical screw feeder can deliver the particulate MgCl 2 through a conduit to the molten salt electrolyte bath that is below the molten magnesium layer. In another embodiment disclosed in the '563 patent, the particulate MgCl 2 can be delivered onto a free surface of the molten salt electrolyte bath.
[0006] Each of these systems for replenishing the particulate MgCl 2 must confront the problem of submerging the particulate MgCl 2 into the molten salt electrolyte. The particulate MgCl 2 is difficult to submerge into the molten salt electrolyte because of its inherent wetting characteristics as a function of surface tension. Accordingly, it is desirable to provide an apparatus, system and method to promote the submersion of the MgCl 2 particulates into the molten salt electrolyte to replenish the system for producing molten magnesium. Furthermore, it is desirable to provide an apparatus, system and method to promote the submersion of materials, in general, into a molten liquid to replenish a system that produces molten liquid, or the like.
SUMMARY OF THE INVENTION
[0007] A molten metal submergence device includes a submergence chamber, an inlet pipe, and a vortex breaker. The submergence chamber is defined by a side wall and includes an inlet in communication with an associated molten metal bath and an outlet in communication with the associated molten metal bath. The inlet is positioned in relation to the side wall such that material passing through the inlet is introduced at least substantially tangentially to the side wall. The inlet pipe is in communication with the inlet of the submergence chamber. The inlet pipe is configured to depend from a wall of the submergence chamber within the confines of the side wall. The vortex breaker is disposed in the submergence chamber between the inlet and the outlet.
[0008] According to the present invention, a new method for submerging metal salts is provided. The method includes providing a chamber that is separate from while in communication with a molten salt electrolyte bath. The method also includes pumping molten salt electrolyte from the molten salt electrolyte bath through an inlet of the chamber. The method further includes creating a vortex of molten salt electrolyte inside the chamber. The method also includes introducing solid metal salt into the chamber to create a molten salt electrolyte and solid metal salt mixture. Typically, the solid metal salt will be in particulate form, such as a powder with an average particulate size of about 80 microns. The method further includes flushing the mixture inside the chamber through an outlet back into the molten salt electrolyte bath.
[0009] According to the present invention, a new system for submerging metal is provided. The system includes a closed top cell holding molten salt electrolyte, a molten metal layer floating on the molten salt electrolyte and a gas space interposed between the molten metal and a top of the well. A chamber is disposed inside the well. The chamber includes at least one side wall and a base wall. An inlet is disposed on one of the walls of the chamber. The inlet communicates with an inlet pipe. The inlet pipe communicates with a pump disposed in the cell. The pump delivers molten salt electrolyte to the chamber. A vortex breaker is disposed in the chamber. An outlet is disposed on one of the walls of the chamber below the inlet, which may include the bottom wall. The outlet communicates with an outlet pipe. The outlet pipe delivers the molten salt electrolyte to the cell in the molten salt electrolyte bath below the molten metal layer.
[0010] The advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention can take physical form in certain parts and arrangements of parts, preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings. Since the drawings only disclose preferred embodiments, the invention must not be limited to the depictions shown herein.
[0012] FIG. 1 is a schematic view of a portion of an electrolytic cell including the metal submerging apparatus of the present invention.
[0013] FIG. 2 is top plan view of FIG. 1 taken at line B-B.
[0014] FIG. 3 is a top plan view of FIG. 1 taken at line C-C.
[0015] FIG. 4 is the portion of the electrolytic cell including the metal submerging apparatus of FIG. 1 showing an example of a vortex in a chamber of the metal submerging apparatus and an alternative vortex breaker.
[0016] FIG. 5 is a table of test results from water modeling testing showing feed rate of polypropylene as a function of pump speed in RPM.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] It is to be understood that the specific devices, processes and systems illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Even though the apparatus, method and system will be described in connection with submerging particulate metal salts into a molten salt electrolyte, it is understood that the invention can be used to submerge other materials, including, but not limited to, scrap, dust, and other solids, and even other liquids into a bath not limited to molten salt electrolytes. Hence, specific examples and characteristics relating to the embodiments disclosed herein are not to be considered as limiting.
[0018] Referring to FIG. 1 , a portion of a cell, which can comprise a portion of an electrolytic cell, is generally designated at 8 . The cell 8 includes side walls (not shown), and a base wall (not shown). The cell also includes a top 10 that covers and optionally seals the cell when the cell is in operation. The side walls, the base wall and the top can include a refractory lining, which is well known in the art, and need not be described in greater detail. The top 10 includes an opening 12 to a charging well 13 defined by wall 15 , through which a metal submerging apparatus 20 is received. Since this invention is applicable as a component for existing electrolytic cells, the metal submerging apparatus and all of its components are sized to be received inside the charging well 13 through the top opening 12 .
[0019] The cell 8 holds a molten salt electrolyte bath 14 , a molten metal layer 16 , and a gas space 18 . The molten salt electrolyte bath 14 , the molten layer 16 , and the gas space 18 are well known in the art and described in U.S. Pat. No. 5,439,563. As a result of an electrolytic process that takes place in the electrolytic cell, the molten metal layer 16 is formed on top of the molten salt electrolyte bath 14 and, in the case of magnesium formed from magnesium chloride, chlorine is also formed. The chlorine is removed from the magnesium metal production system in a process that is also well known in the art.
[0020] In the case of producing magnesium metal from MgCl 2 , particulate MgCl 2 is introduced into the molten salt electrolyte bath 16 . Through the electrolytic process, the MgCl 2 is converted into molten magnesium and chlorine gas. The molten magnesium 16 is then removed. Accordingly, either intermittently or continuously, more particulate MgCl 2 must be introduced into the system to replenish the MgCl 2 that has been converted into molten magnesium and chlorine. The present invention is capable of either, but is particularly beneficial as a continuous process. The metal submerging apparatus 20 is disposed inside the cell 8 to facilitate submergence of the particulate MgCl 2 into the molten salt electrolyte bath 14 .
[0021] The metal submerging apparatus 20 generally includes a submergence chamber 22 where a vortex flow of molten salt electrolyte is created and a vortex breaker 24 to direct the vortex flow out of the chamber. In addition to the creation of a vortex, a general turbulent flow of molten salt electrolyte can also be created inside of the chamber to facilitate submersion of the particulate MgCl 2 . An inlet pipe 26 delivers molten salt electrolyte from the molten salt electrolyte bath 14 to the chamber 22 . The molten salt electrolyte is delivered to the chamber such that it intersects the chamber in a tangential direction, so that a vortex is formed. The vortex breaker 24 disrupts a vortex of the molten salt electrolyte that has been produced in the chamber 22 to direct the vortex flow of the molten salt electrolyte out of the chamber. Particulate MgCl 2 is delivered to the chamber 22 . The order of the creation of the vortex and the delivery of the particulate is not critical. The vortex that is formed in the chamber facilitates the submergence of the particulate MgCl 2 . The molten salt electrolyte and MgCl 2 mixture is then delivered back to the molten salt electrolyte bath via a discharge pipe 28 .
[0022] The system will now be described as molten salt electrolyte flows through the submergence system. An impeller 32 of a pump 33 is disposed in the molten salt electrolyte bath 14 . The impeller 32 is mounted to a shaft 34 . The shaft 34 is connected to a motor 36 that rotates the shaft, which rotates the impeller 32 . The impeller 32 is housed in a pump housing 40 that includes an inlet 42 to draw molten salt electrolyte into the pump housing. The housing 40 also includes an outlet 44 in communication with a discharge pipe 46 . The discharge pipe 46 communicates with the inlet pipe 24 . The inlet pipe 24 communicates with a chamber inlet 48 on a side wall 50 of the chamber 22 . Advantageously, the pump 33 and submerging apparatus 20 are both fitted within the charging well 13 .
[0023] The chamber inlet 48 is positioned so that molten salt electrolyte that enters the chamber enters at a generally horizontal angle. The horizontal orientation of the inlet 48 promotes formation of the molten salt electrolyte vortex inside of the chamber. The inlet 48 of the chamber is shown on a side wall 50 of the chamber; however, the inlet could also be located on a base wall 52 of the chamber. The inlet 48 could also straddle both the side wall 50 and the base wall 52 of the chamber 22 . The terms side wall and base wall are used simply to describe the figures, in that both the side wall and the base wall in combination can form the side wall of the metal submerging apparatus. As more clearly shown in FIG. 2 , the side wall 50 is generally circular in cross-section. The circular orientation of the side wall 50 further facilitates the creation of the molten salt electrolyte vortex inside of the chamber 22 .
[0024] The vortex breaker 24 is situated near the chamber inlet 48 . In one embodiment of the invention, the vortex breaker 24 comprises a ramp 60 , similar to the ramp disclosed in U.S. Pat. No. 6,217,823, which is incorporated herein by reference. As seen in FIG. 3 , the ramp 60 includes an inner edge 62 and a leading edge 64 positioned adjacent the inlet 48 . Molten salt electrolyte flows up the ramp 60 within the chamber 22 and spills over the inner edge 62 into a cavity 66 and exits through an outlet 68 positioned below the inlet 48 . While it is beneficial that the ramp 60 be sloped, this does not need to be achieved by a constant incline. For example, the ramp 60 can be sloped over a first portion, and be horizontal over a final portion. Similarly, the ramp need not encircle the entire side wall 50 . Accordingly, the invention is intended to encompass all versions of a sloped ramp.
[0025] In an alternate embodiment, the vortex breaker can take form in a blade 80 ( FIG. 4 ) positioned on the side wall 50 . The blade can be any shape including the device disclosed in U.S. Pat. No. 6,036,745, which is incorporated herein by reference. In this embodiment, the molten salt electrolyte enters the chamber 22 via the inlet 48 in a horizontal direction. The horizontally moving molten salt electrolyte contacts the blade resulting in a break in the vortex causing the molten salt electrolyte to move downward an out the outlet 68 .
[0026] In an alternate embodiment, the vortex breaker can comprise a system including a second inlet (not shown) that delivers a second molten salt electrolyte stream positioned below the horizontal chamber inlet 48 that delivers a first molten salt electrolyte stream. This system for creating a vortex is similar to that described in U.S. Pat. No. 4,286,985, incorporated herein by reference. In this embodiment, the horizontal chamber inlet 48 intersects the chamber 22 in a tangential manner while the second inlet, which also delivers molten salt electrolyte, intersects the side of the chamber 22 in a substantially radial manner. Accordingly, the second molten salt electrolyte stream breaks the vortex flow of the first molten salt electrolyte stream directing both the molten streams out of the outlet 68 of the chamber 22 .
[0027] In addition to the vortex systems described above, the vortex of the molten salt electrolyte can be achieved using any know apparatus, system or method that will result in a vortex. As stated above, the creation of a vortex facilitates the submergence of the particulate MgCl 2 into the molten salt electrolyte. Additionally, the vortex can be broken to direct the molten salt electrolyte stream out of the chamber in any known manner.
[0028] Referring back to the flow of the molten salt electrolyte through the metal submergence system, the molten salt electrolyte exits the chamber via the outlet 68 . The outlet 68 communicates with the discharge pipe 28 . The discharge pipe 28 includes an outlet 72 disposed in the molten salt electrolyte bath 14 below the molten metal 16 . The molten salt electrolyte is discharged below the molten metal layer 16 so as not to disturb the molten metal layer. Accordingly, the length of the discharge pipe 28 can be modified as a function of the depth of the molten metal layer 16 .
[0029] Particulate MgCl 2 is fed into the metal submergence apparatus 20 via a cell feed pipe 74 . The cell feed pipe 74 can deliver the particulate MgCl 2 via a screw feeder operator or a spinning distributor, as disclosed in U.S. Pat. No. 5,439,563. The cell feed pipe can also deliver the particulate MgCl 2 to a plurality of sprayers that will inject the particulate MgCl 2 into the chamber. In addition to those, the cell feed pipe 74 can deliver the particulate MgCl 2 via any distribution system that can deliver the particulate matter to the chamber 22 . Accordingly, the particulate matter is delivered to the chamber 22 where it submerges into the molten salt electrolyte flowing in the chamber resulting in a mixture of particulate MgCl 2 and molten salt electrolyte.
[0030] As has been stated above, since this invention is applicable as a component for an existing electrolytic cell, the metal submerging apparatus 20 , and all of its components, can be designed to be received inside the opening 12 in the top 10 of the cell 8 . In some known apparatus, this opening 12 can be smaller than 30 inches. Accordingly, the chamber 22 and the pump must be sized such that a vortex can be created in this limited space. Furthermore, the impeller 32 is positioned near the chamber, when measured in a direction parallel to the top 10 of the cell, due to the limited space that the metal submerging apparatus 20 is allowed to occupy when retrofitting such cells.
[0031] With a vertical discharge pipe 26 , the nadir of the vortex can be positioned inside of the discharge pipe 26 ( FIG. 4 ). This can be achieved through proper dimensioning of the chamber 22 in combination with adjusting the rate at which molten salt electrolyte is fed to the chamber 22 by the rotating impeller 32 . Accordingly, the metal submerging apparatus 20 can be retrofitted into an existing electrolytic cell having a short height and the metal submergence apparatus can still fit into this limited space. Moreover, the available height for the chamber 22 does not limit the submergence apparatus 20 because the rate of rotation of the vortex, which helps determine the height the molten salt electrolyte will reach on the chamber wall 50 , can be controlled by the feed rate from the pump. However, it has generally been shown that a relatively steep inclined vortex is beneficial in achieving efficient particulate submergence.
[0032] The following examples are provided to facilitate the explanation of the invention but are not intended to limit the invention to the specific embodiments disclosed.
EXAMPLES
[0033] Water modeling tests of the present system were conducted to evaluate the submergence performance. It is recognized that the most difficult part of the MgCl 2 melting process is particle contact with the molten metal salt. Therefore, particle contact would represent the rate controlling effect. Contact angle, as a function of surface tension, was used to judge wetting characteristics of the feed stock.
[0034] In the water modeling tests, polypropylene powder was used as the feed stock because of its high surface tension with water. Furthermore, polypropylene proved a difficult option as it was not melted or dissolved by the water medium. Accordingly, choosing polypropylene powder as a feed stock in the water model represented a worse case scenario as compared to the submergence of MgCl 2 in an electrolytic system.
[0035] In the test, the polypropylene powder had a diameter of 80 microns, which is similar to the particulate size of MgCl 2 feed stock used in present electrolytic systems. Buoyancy effects were also held constant for the water modeling tests. The ratio of specific gravity of the liquid to bulk density of the feed stock was approximately 2:1, which is approximates the ratio in an MgCl 2 system. The feed rate was demonstrated based on a constant volume calculation based on bulk density.
[0036] A summary of the properties of the materials used in the water modeling tests versus the equivalent properties in an actual MgCl 2 electrolytic system are provided below.
[0000]
MgCl 2
Polypropylene/Water
Bulk Density of the feed stock
900
g/l
450
g/l
Specific Gravity of the liquid
1700
g/l
1000
g/l
Contact Angle of the feed stock
>90°
105°
Particle Size of the feed stock
80
microns
80
microns
[0037] The design focused on maximizing the powder to liquid contact time while ensuring a high feed rate. The submergence apparatus used a Metaullics® D13 pump in conjunction with a 13″ ID chamber. The tests measure maximum wetting and submergence rate of the polypropylene powder at various pump speeds. Discharge diameter was varied to maximize the submergence and wetting rate. The results are plotted in the table at FIG. 5 . Note that the feed rates in actual kg/hr of polypropylene submerged is about half the amount of MgCl 2 that could be submerged using the submergence apparatus due to the difference in bulk density between MgCl 2 and polypropylene.
[0038] The points for FIG. 5 are as follows:
[0000]
4″ Outlet
5″ Outlet
RPM
sec/5 kg
kg/hr
RPM
sec/5 kg
kg/hr
1200
88
204.55
1200
54
333.33
1400
74
243.24
1400
36
500.00
1800
22
818.88
1800
16
1125.00
[0039] The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations.
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A molten metal submergence device includes a submergence chamber, an inlet pipe, and a vortex breaker. The submergence chamber is defined by a side wall and includes an inlet in communication with an associated molten metal bath and an outlet in communication with the associated molten metal bath. The inlet is positioned in relation to the side wall such that material passing through the inlet is introduced at least substantially tangentially to the side wall. The inlet pipe is in communication with the inlet of the submergence chamber. The inlet pipe is configured to depend from a wall of the submergence chamber within the confines of the side wall. The vortex breaker is disposed in the submergence chamber between the inlet and the outlet.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to generally to apparatus for steaming garments and particularly to a fixture for supporting garments which are to be steamed by means of a hand-held steamer.
2. Description of the Prior Art
In the recent past, so-called "hand steamers" for home use have been made commercially available. Such hand-held steamers are typically powered by standard house current like many other hand-held electric home appliances. The hand-held steamer, typically of lightweight construction, includes an electrical heating element and a reservoir for holding a quantity of water. The water is converted to steam during the operation of the hand-held steamer. A steam outlet of the steamer is directed against wrinkled fabric portions of a garment. The steam tends to restore the natural shape of the garment.
Though hand-held steamers have proven to be valuable home appliances for removing unwanted wrinkles from most garments, the effectiveness of their use is sometimes hampered in the absence of an efficient way to hold a garment to be steamed. In many instances, the need to quickly restore a suit, coat, jacket or skirt comes up unexpectedly, when the garment is taken from the closet, and time to meet a busy schedule is running short. For example, when on a Sunday afternoon, garments are packed for an important Monday morning business trip. In these types of situations, the immediate availability of a practical work site for steaming the garments becomes invaluable.
A garment support used by some commercial cleaning and pressing establishments in conjunction with hand-held steamers provides a wall-mounted backplate. At the top and center of the backplate, a clamping and hanger linkage provides for the temporary suspension of a garment either by clamping the garment against the backplate, or as a structure for holding a hanger in suspension while a garment is steamed. The garment clamping linkage is activated by a foot switch which is coupled through a cable connection to the clamp at the top of the plate.
The described support for garments during steaming operations may be useful for commercial operations. However, the complexity of the installation with the foot switch mechanism and the fixed height at which the garment holder is mounted render such installation in a home undesirable. Since hand-held steamers are typically used only occasionally in the home, and ready availability and unobtrusive storage of equipment used with such steamers are desirable, commercial installations have failed to meet the needs of home users of hand-held steamers.
Various other devices for steaming garments are known which typically do not contemplate the use of a hand-held steamer. Instead, they provide a support for specific garments and permit steam to be introduced into the garment, and to be distributed somewhat uniformly from the inside of the garment through virtually all of its material, while the garment is supported by a frame. The frame approximates the shape of a person wearing the garment. While such fixtures or garment supports may be practical in their specific applications, the specificity of their applications or the generally increased consumption and release of steam as the result of steaming a garment in its entirety makes these appliances more suitable for larger volume use, such as in commercial cleaning and steaming applications, as opposed to occasional home use.
Other supports, such as ironing boards or table surfaces are sometimes used in conjunction with hand-held steamers. Ironing boards are used because of their availability in many households in which hand-held steamers have come into use. Ironing boards typically occupy a stow-away place in a closet and are quickly set up. Table surfaces are sometimes used because of their convenient availability in emergencies created by time pressures of current lifestyles. Horizontally disposed supports, however, have been found to be less than ideal for removing wrinkles from garments with hand-held steamers.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a workstation for steaming garments, which workstation can be unobtrusively stored and, yet, be readily available when needed.
It is another object of the invention to provide such a workstation in form of a steam board of a size suitable for ready storage, and to provide a practical, adjustable garment support for allowing garments of various sizes to be suspended in a position that the wrinkled portions are located in superposition with a work area of the steam board. Such suspension of garments frees up both hands of the person intending to use a hand-held garment steamer, allowing garments to be stretched and rearranged with one hand during the steaming operation while holding the steamer in the other hand.
It is a further object of the invention to provide protection for wall or panel areas which make desirable workstations areas for steaming wrinkles from garments.
Another object is to provide for a convenient, vertically adjustable suspension of garments to permit the garments to hang under their own weight, thereby facilitating the use of a hand-held garment steamer at a convenient height without a need of excessive stooping or reaching.
These and other objects and advantages are realized by a new and improved steam board with an adjustable garment support. An elongate mounting bracket is attached at one end to a central, upper area of a back surface of a steam board of essentially rectangular shape. The mounting bracket extends in the plane of the steam board away from the steam board and is oriented such that a longitudinal projection of the steam board essentially passes through the centroid of the board. Thus, a mounting implement on the upper end of the mounting bracket permits the steam board to be suspended in a vertically stable position by the mounting bracket, such that the steam board rests essentially parallel adjacent a wall, panel or door to which the mounting bracket may be attached. A garment hanger bracket is provided with a first implement for adjusting the position of the hanger bracket toward and away from the steam board along the length of the mounting bracket, and with a second implement for suspending a garment hanger at various shifted positions with respect to the steam board.
The first adjustment implement allows the garment hanger bracket to be moved away from or toward the steam board, depending on whether respectively longer or shorter garments are to be steamed. The second adjustment implement permits a person to quickly reposition a garment with respect to the steam board during the steaming operation to move wrinkled portions of the garment to a conveniently accessible working height in front of the steam board.
BRIEF DESCRIPTION OF THE DRAWING
Various features and advantages of the invention are better understood when the following detailed description of the invention is read in reference to the appended drawing, wherein:
FIG. 1 shows an overall view of a steam board as a particular embodiment of the invention relative to a typical environment to which its advantages apply;
FIG. 2 is an exploded view of the steam board of FIG. 1, showing structural details of the preferred embodiment of the invention, including a mounting structure at a top end of the mounting bracket for a suspension of the steam board from the top of a panel or closet door;
FIG. 3 shows the steam board of FIGS. 1 and 2 in an assembled condition in which a garment hanger bracket is disposed in a lowermost position;
FIG. 4 shows an alternate embodiment of a mounting structure at an upper end of a mounting bracket in distinction over the mounting structure shown in FIG. 2;
FIG. 5 depicts an alternate embodiment of the garment hanger bracket shown in FIGS. 1, 2 and 3; and
FIG. 6 is a top view of the garment hanger bracket of FIG. 5, showing a support structure extending from the front surface of the mounting bracket.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown a steam board assembly, generally referred to by the numeral 10, depicting a preferred embodiment of this invention. The steam board assembly 10 is shown in relationship to a wardrobe, depicted in phantom lines and designated generally by the numeral 11, as an illustrative example of an environment with respect to which certain features of the invention are more readily explained. The steam board assembly 10 includes a generally rectangular board 12, and an elongate mounting bracket 14 which is centrally attached with a first, lower end portion 16 adjacent an upper edge 18 to a back surface 21 of the board 12. A second, upper end portion 22 of the mounting bracket 14 is in its preferred embodiment formed to fit smoothly over the top of a vertically disposed panel, such as a closet door 23 shown here in phantom lines. A short, second ledge 24, formed downward at the very end of the end portion 22 permits the end portion 22 to remain securely in position over the door 23, as shown in FIG. 1. The formed end portion 22 provides, consequently, a convenient means for attaching the steam board assembly 10 to an open door 23, provided such door is accessible from above.
Since the central attachment of the mounting bracket 14 to the board 12 is desirably symmetrical such that the downwardly extended length of the mounting bracket 14 passes in essence through, or immediately past, the centroid 26 of the board 12, the steam board assembly 10 becomes suspended in a vertically stable position. Feet 31 of a resilient material, such as rubber, are attached to the back surface 21 of the board 12. In the preferred embodiment of the invention, there are four of such feet 31, each respectively attached adjacent a different one of the four corners 32 of the board 12. Also, the feet 31 cause the back surface 21 of the board 12 to rest spacedly in parallel with the door 23 without marring its surface 33.
A garment hanger bracket 35 is shown in an upper position, having been adjusted in the direction of an arrow 36 to extend even above the door 23. A long garment 37, such as a typical woolen overcoat or a dress, is shown in FIG. 1 in phantom lines as being suspended by a hanger 38 from an upper end 39 of the hanger bracket 35. In the depicted arrangement, a hanger hook 40 of the hanger 38 is retained by the hanger bracket 35. It is to be noted that when the hanger bracket 35 is in an upwardly adjusted position and a long garment is suspended by the hanger 38 from the hanger bracket 35, a lower hem 41 of the garment 37 is positioned in alignment with the lower portion 42 of the board 12 and ready to be steamed. ;
FIG. 2 shows the generally described components of the steam board assembly 10 in greater detail. The board 12 is in the preferred embodiment of generally rectangular shape, having preferably a height of 36 inches and a width of 24 inches. The board is preferably of a water-resistant type (exterior grade) one-half inch thick plywood. The water resistant qualities are preferred because of the exposure of the surface of the board 12 to the hot steam emanating from a hand-held steamer (not shown) during the steaming of a garment, such as the garment 37 shown in FIG. 1.
A front surface or working surface 44 of the board 12 is covered by an inner sheet 46 of resilient, loosely matted, polyester material, which may be either of a woven or non-woven type. The qualities of such material have been found to allow steam which is directed against its surface to pass laterally through its material. The preferred thickness of the sheet 46 is approximately one-sixteenth to one-eighth of an inch in its uncompressed state. If a stream of steam is directed vertically into the sheet, the steam becomes deflected by the working surface 44 of the board 12 and disperses laterally through the sheet 46 to outwardly away from the working surface 44 of the board 12 in an area adjacent to the area of the board against which the stream of steam is directed. The described dispersing action has been found to enhance the action of the steam, in that the garment 37 (See FIG. 1) is being steamed from both the front and in surrounding areas of the impinging steam also from the rear by the steam escaping from the front surface 44 of the board 12.
The inner sheet 46 is covered by an outer sheet 48 of material which is, relative to the inner sheet 46, of greater strength. In the described embodiment, the outer sheet or cover sheet 48 is a woven material, such as poplin, of preferably 65 percent polyester and 35 percent cotton, and, yet, of a density which will permit impinging steam to pass through the fabric. The inner sheet is loosely fastened to the front surface 44 of the board 12. This may be accomplished in any number of ways, such as adhesively tacking the material to the surface 44, or by using tacks or staples 50 in areas of the periphery of the board 12. Since the staples 50 would be exposed to some extent to steam, the use of stainless steel or other non-corrosive material for the tacks or staples 50 would be preferred.
As shown in the broken view of the board 12 in FIG. 2, the inner sheet 46 preferably does not extend over edges, such as vertical edges 51 of the board 12, even though a wrapping structure could be used. The cover sheet 48, however, is preferably tightened over the edges, e.g., edges 18, 51, of the board 12 and stapled to the back surface 21 of the board 12. The resilient feet 31 are preferably fastened to the board 12 with screws 52 after the cover sheet 48 is attached to the board 12 as described.
The elongate mounting bracket 14 is attached as shown in FIG. 2 by screws 55. The manner of attachment of the lower end portion 16 of the mounting bracket 14 to the board 12 is one of preference. Preferably, three vertically arranged countersink mounting screws 55 are inserted through respectively formed holes 56 in the lower end 16 of the mounting bracket 14. A body portion 57 of the bracket 14 extends over a length of about 18 inches above the upper edge 18 of the board 12. The upper end portion 22 is in its preferred embodiment formed at a right angle to the length of the bracket 14, defining a support member 58. The width of the member 58 is chosen to be one and seven-eighths of an inch in its extent between a back surface 59 of the mounting bracket 14 and the retainer ledge 24, such that the member 58 fits over doors of most common widths as used in current building constructions.
A front surface 63 of the body portion 16 of the bracket features two spacedly formed hanger bracket retainer structures, designated generally by the numeral 64. The two structures 64 are spaced from each other in the direction of the longitudinal extent of the body portion 16 by a predetermined set distance "D" which corresponds to matching features in the garment hanger bracket 35, as will be described herein below. A pair of oppositely formed ears 65 extend in juxtaposition from the front surface 63 and are spaced to accept between inner surfaces 66 the thickness of the hanger bracket 35 in supporting engagement. Each of the ears 65 has an aperture 60 to accept a cylindrical retainer pin 67. The inserted retainer pin 67 may be secured in the inserted position by a small cotter pin (not shown), or by providing locking screw threads at one of the ends of the pin 67.
The described retainer structures 64 are intended to engage the hanger bracket 35. In conjunction the two retainer structures define a support for the hanger bracket 35, in that it is contemplated to engage both structures 64 for vertical and lateral support of the hanger bracket 35.
The hanger bracket 35 is an elongate, rigid member, preferably of a material which imparts rigidity and strength, such as steel or aluminum. The hanger bracket 35 has a top end 68, a bottom end 69 and front and rear surfaces 71 and 72, respectively, extending substantially the length of the bracket 35. The front and rear surfaces 71 and 72 are modified from planar surfaces or edge surfaces to serve functions, as described herein below.
In the preferred embodiment the hanger bracket 35 is a straight, elongate bar, and the front and rear surfaces 71 and 72 are front and rear edges 71 and 72, respectively, the width of the edges being defined by the thickness of the bar stock from which the hanger bracket 35 is formed. The rear edge 72 is serrated by a plurality of equally spaced "L"-shaped notches 73 which extend essentially orthogonally to the rear edge 72 into the bracket 35. All notches 73 are identical in shape, size and location with respect to the rear edge 72, to form in conjunction with the virgin surface of the rear edge 72 a plurality of spaced key members 74. The widths of the key members 74 is chosen to correspond to a gap 75 between adjacent surface portions of the front surface 63 of the mounting bracket 14 and the respective retainer pin 67 bridging the gap 75 of the retainer structure 64. It should be noted that the notches 73 are of uniform width which corresponds, except for a standard allowance configured for sliding engagements, to the diameter of the retainer pins 67. The uniform width of each notch results in the key members being rectangular in shape. Also, the spacing or pitch of the notches 73 is chosen to correspond to the predetermined set distance "D" between the two retainer structures 64 along the length of mounting bracket 14. The hanger bracket 35 becomes engageable with the retainer structures 64 by hooking two selected, adjacent ones of the key members 74 over the retainer pins 67. The retainer pins 67 thereby suspend the hanger bracket 35 at a selected distance from the board 12. The set distance or magnitude of the adjustment height of the hanger bracket 35 from the board 12 is, of course, determined by which two of the key members 74 along the rear edge 72 of the hanger bracket 35 are selected for engagement.
The rectangular shape of the key members 74 causes the retaining engagement of the key members 74 when inserted over the retainer pins 67 to be non-wedging. On the other hand, by changing the shape of the notch 73 to be wider at its opening than at its end would allow for a wedging engagement of the key in the gap 75. This wedging, engagement, while within the scope of the present invention, is not contemplated in the preferred embodiment thereof because of the added effort that would have to be exerted in changing the adjustment of the hanger bracket 35.
It is also to be realized that a single one of the retainer structures 64 could be employed to engage and retain a single one of the key members 74. In such a deviation from the preferred embodiment, a lateral stability of the anger bracket 35 tends to be less with respect to that of the described structure. Increasing the width of the ears 65 overcomes in part such a reduction in lateral support. A forward pivotal support of the hanger bracket 35 is also reduced when only one point of engagement is used. However, locating the hanger bracket 35 by the retaining engagement of only one selected one of the key members 74 with a respectively single retainer structure 64 is considered to be a possible modification within the scope of this invention.
The front edge 71 of the hanger bracket 35 is also shaped or modified from a straight line by a plurality of equally spaced hanger hook retainer recesses, designated generally by the numeral 76. The spacing or pitch between adjacent ones of the recesses 76 is preferably less than the spacing between the notches 73 into the hanger bracket 35 along its rear edge 72. The key members 74 are intended to permit a gross vertical adjustment of the hanger bracket 35 with respect to the board 12 in preparation for steaming long garments, such as the garment 37 (See FIG. 1), short garments, such as jackets, or garments of intermediate length, such as skirts. However, while one may have prepared for the steaming of garments of a such a predetermined length, exceptions may require some small vertical adjustment. Also, during the steaming of a single garment wrinkles at opposite extremities of such garment may be noticed, in which case the ability to quickly reposition a garment is of great convenience. The hanger hook retainer recesses 76 are intended to facilitate positioning a selected garment, such as garment 37, in such a position in front of the board 12, that the areas of the garment 37 which need to be steamed are conveniently located without excessive reaching or stooping. Thus, the retainer recesses 76 are available for quick, vertical adjustments of the garment 37 during steaming operations, and toward that purpose, each of the hanger retainer recesses 76 has an upwardly pointing lip 77 on its lower edge 78. The lip 77 retains the hook of a hanger 38 that may be placed into the respective recess 76. The convenient spacing of the hanger hook retainer recesses 76 is chosen to be one inch along the front edge 71 of the hanger bracket 35.
The front edge 71 and, consequently, the recesses 76 therein are in the preferred embodiment disposed at a slope with respect to the vertical, in that the spacing between the front edge 71 and the rear edge 72 is greater at the top end 68 of the hanger bracket 35 than at the bottom end 69 thereof. While the resulting negative slope of the front edge 71 of the hanger bracket 35 is not essential, it is considered advantageous to have the lower portions of the front edge 71 slightly recessed from the hanger 38 and from the garment 37 thereon, when the hanger 38 is suspended by one of the upper recesses 76.
The bottom end 69 of the hanger bracket 35 features a larger aperture 81 without an opening or break-through to either the front or rear edges 71 or 72 of the bracket 35. This larger aperture is provided for convenience to be engaged by any specialty hanger that may not otherwise fit the recesses 76. Some types of commercially available molded plastic hangers (not shown) could be considered for use with the aperture 81.
FIG. 3 shows the steam board assembly 10 with the hanger bracket 35 in its lowermost position. In this position of the hanger bracket 35, it is possible to suspend a garment shorter than the garment 37 (See FIG. 1) in front of the board 12 and completely within the confines defined by the extent of the front surface 44 of the board 12.
FIG. 4 shows an alternate embodiment of the invention, and particularly a modified upper end portion 84 of the mounting bracket 14. The modified end portion 84 shows a planar continuation of the elongate body portion of the mounting bracket 14 to its upper end. Mounting holes 85 are formed adjacent the upper end into the upper end portion 84 with mounting screws 86 inserted through such mounting holes 85 to fasten the steam board assembly to a surface of a straight wall (not shown). While such alternate embodiment still incorporates other features of the invention, the alternate embodiment does not permit the same ready placement or removal of the steam board 10 from the door 23 shown in FIG. 1. FlG 4 also shows a detail of a threaded portion 88 which engages a complementary thread in the respective aperture 89 of an adjacent ear 90 of a thus modified retainer structure 91.
FIG. 5 shows an alternate embodiment of a hanger bracket which is designated generally by numeral 92. Instead of the straight bar type shape of the hanger bracket 35, the alternate shape is a formed piece with a projection or cross section in the shape of a "V", as depicted in FIG. 6. The "V"-shape establishes the rear surface 72 in the form of the top edges of the "V", while the front surface 71 is defined by the bottom of the "V".
The alternate shape of the hanger bracket 92 necessitates a modification of the mounting bracket 14 and particularly of the retainer structures 64. FIG. 6 shows a modified retainer structure 93 in which a centered support 94 is staked or otherwise attached to extend perpendicularly from the front surface 63 of the mounting bracket 12. A retainer pin 95 is resistance-welded, brazed or otherwise fastened in a known manner through a locating aperture 96 in the support 94 to establish the predetermined gap 75 between the front surface 63 of the mounting bracket 12 and the adjacent surface of the retainer pin 93. The gap 75, as described above with respect to the preferred embodiment, receives the respective key members 74 at now both respective rear edges 72 of the alternate hanger bracket 92 to become retained between the front surface 63 and the retainer pin 95. The hanger hook retainer recesses 76 are now formed in the bottom 98 of the "V", as the equivalent of the front edge 71 of the hanger bracket 35.
From the aforegoing detailed description of the preferred embodiment of the invention and a description of desirable modifications thereof, it is to be recognized that the described and other changes and modifications are possible in the preferred embodiment without departing from the spirit and scope of the invention. This invention is to be defined and limited only by the scope of the claims appended hereto.
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A board is vertically mountable to a wall or door and features an upwards extending support structure to which a garment hanger support bracket is attached. The garment hanger support bracket is itself vertically adjustable to permit hangers to be supported relatively higher or lower with respect to the board. A vertical adjustment of the bracket consequently allows respectively longer or shorter garments to be hung in a substantially centered position in front of the board. In addition the garment hanger support bracket features a plurality of vertically spaced hanger support recesses which allow a garment to be vertically relocated during a steaming operation without the need to vertically readjust the garment hanger support bracket itself. This latter feature permits a garment to be vertically shifted to bring wrinkles in upper and lower portions of the garment to a convenient working height.
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TECHNICAL FIELD
[0001] The present invention relates to the field of the control, using an electric power generator, of applications implementing at least one piezoelectric, electrostrictive or magnetostrictive transducer, and in particular, but not exclusively, an ultrasonic transducer.
PRIOR ART
[0002] Many industrial applications exist implementing at least one piezoelectric, electrostrictive or magnetostrictive transducer (also called an actuator), which makes it possible to control a mechanical movement, such as a mechanical vibration, a displacement or a mechanical shock, using an electric or magnetic field.
[0003] More particularly, in the particular case of mechanical vibration generation, vibrating mechanical waves, and in particular ultrasonic waves, are used in a very large number of industrial fields, for example, and non-limitingly and non-exhaustively, cleaning, cutting, welding, etc.
[0004] Irrespective of the type of application, at least one piezoelectric, electrostrictive or magnetostrictive transducer is used, which is powered by an electric power generator, and which makes it possible to transform the electricity supplied by the generator into a mechanical movement.
[0005] In the particular case of a vibrational movement, the electricity supplied by the generator is transformed into a vibrating mechanical movement in a range of frequencies and amplitudes that in particular depends on the application. Many industrial applications use a vibrating mechanical movement controlled by a transducer operating in the ultrasound domain (frequencies typically exceeding 20 kHz). However, some applications may also use a transducer operating at frequencies below 20 kHz.
[0006] More particularly, in the vibrational field, the electric power generator delivers a power signal, the frequency and voltage of which can for example be adapted to the resonance or anti-resonance frequency of the transducer during operation in its environment. Most often, this power signal delivered by the generator is adjustable (for example in frequency and/or amplitude). Furthermore, in some known embodiments, this power signal delivered by the generator is controlled using external instructions and information (for example, current and voltage) measured on the transducer.
[0007] For many years, the control part was done in an analog manner, which required complex adjustments and made the control devices rigid and difficult to adapt. One control example of an ultrasonic transducer with analog control is for example described in American patent U.S. Pat. No. 5,406,503.
[0008] More recently, the use of digital control-based solutions has made it possible to incorporate new functionalities into the control of the operation of the transducer. Control examples of an ultrasonic transducer with digital control are for example described in the following publications: European patent applications EP-A-1 835 622, EP-A-1 216 760, EP-A-1 199 047 and EP-A-1 588 671.
[0009] It is remarkable to note that the described devices remain relatively rigid in their embodiment and are most often specific to a given application, i.e., a given type of piezoelectric, electrostrictive or magnetostrictive transducer.
Aim of the Invention
[0010] One aim of the invention is to propose a new technical solution for using a suitable electric power generator to control applications implementing at least one piezoelectric, electrostrictive or magnetostrictive transducer, that solution having the advantage of being universal, i.e., not specific to a single application, and being very flexible and easily adaptable to applications in different technical fields and to piezoelectric, electrostrictive or magnetostrictive transducers having different structures and mechanical properties. Another aim of the invention is to propose a control solution for a piezoelectric, electrostrictive or magnetostrictive transducer that is easy to upgrade, and that can be configured or modified quickly and easily.
BRIEF DESCRIPTION OF THE INVENTION
[0011] The invention thus relates to an electronic device for controlling applications using at least one piezoelectric, electrostrictive or magnetostrictive transducer, said device including an electric power generator suitable for powering at least one piezoelectric, electrostrictive or magnetostrictive transducer, with a control signal, electronic control means capable of automatically controlling the electric power generator by using a control macro-function (M), and an electronic memory in which are recorded:
a first family (A) of control functions including one or more different elementary control functions (An), each elementary control function of the first family (A) making it possible to adjust the amplitude of the control signal, a second family (T) of control functions including one or more different elementary control functions (Tn), each elementary control function of the second family (T) making it possible to adjust the duration of the control signal, a third family (C) of control functions including several different elementary control functions (Cn), each elementary control function of the third family (C) making it possible to adjust the cycle of the control signal, at least said control macro-function (M), which is made up of the assembly of at least three elementary control functions respectively chosen from among the three families of control functions (A, T, C) recorded in the memory. More particularly, but optionally according to the invention, the electronic device according to
the invention may include the following additional and optional technical features, considered alone or in combination:
the electronic memory contains a fourth family (F) of control functions including one or more different elementary control functions (Fn), each elementary control function of the first family (F) making it possible to adjust the frequency of the control signal, and in which said control macro-function (M) is formed by the assembly of at least four elementary control functions respectively chosen from among the four families of control functions (A, T, C, F) recorded in the memory. at least one elementary control function of said control macro-function (M) makes it possible to adjust the amplitude or duration or cycle or frequency of the control signal as a function of at least one adjustment value that is recorded in the electronic memory. the electronic memory contains several different control macro-functions (Mn), which are each made up of the assembly of at least three elementary control functions respectively chosen from among the first, second and third families of control functions (A, T, C) recorded in the memory, and preferably by the assembly of at least four elementary control functions respectively chosen from among the first, second, third and fourth families of control functions (A, T, C, F) recorded in the memory. the electronic memory contains the adjustment value(s) of the elementary control functions of a single control macro-function (M). the electronic memory contains the adjustment value(s) of the predefined elementary control functions of each control macro-function recorded in the electronic memory. The device includes at least one communication port making it possible to put the device in communication with the programmable electronic processing unit, of the microcomputer or programmable logic controller type.
[0022] The invention also relates to a system for controlling applications implementing at least one piezoelectric, electrostrictive or magnetostrictive transducer, said system including an aforementioned electronic device, and an electronic processing unit, which can be connected to said electronic device.
[0023] More particularly, but optionally according to the invention, the system according to the invention may include the following additional and optional technical features, considered alone or in combination:
the electronic processing unit makes it possible, when it is connected to the electronic device, to load at least one control macro-function (M) into the memory of the electronic device. the electronic processing unit makes it possible, when it is connected to the electronic device, to load the elementary functions of each of the function families ((A, F, T) or (A, F, T, C)) into the memory of the electronic device. the electronic processing unit makes it possible, when it is connected to the electronic device, to load the adjustment value(s) of at least one control macro-function (M) into the memory the electronic device. the electronic processing unit, when it is connected to the electronic device, allows a user to select a control macro-function from among a set of control macro-functions (Mn) recorded in the memory of the device, the electric power generator of the device being designed to execute said selected control macro-function. the electronic processing unit includes, in memory, at least all of the elementary control functions recorded in the electronic device, and a program for building macro-functions which, when executed by the electronic processing unit, allows a user to build a control macro-function (M) from said elementary control functions.
[0029] The invention also relates to a computer program comprising computer program coding means that can be executed by the electronic processing means ( 3 ), and making it possible, when it is executed by the electronic processing means ( 3 ), to build control macro-functions (M) from a first family (A) of control functions including one or more different elementary control functions (An), which each make it possible to adjust the amplitude of a control signal that must be generated by an electric power generator, a second family (T) of control functions including one or more different elementary control functions (Tn), which each make it possible to adjust the duration of said control signal, and a third family (C) of control functions including several different elementary control functions (Cn), which each make it possible to adjust the cycle of said control signal.
[0030] More particularly, but not necessarily, the computer program makes it possible to build control macro-functions (M) also from a fourth family (F) of control functions including one or more different elementary control functions (Fn), which each make it possible to adjust the frequency of said control signal.
[0031] The invention also relates to a computer program comprising computer program coding means that can be executed by the electronic processing means, and making it possible, when it is executed by the electronic processing means, to configure a control macro-function (M), wherein said control macro-function (M) comprises a first elementary control function (An), which makes it possible to adjust the amplitude of a control signal (S) that must be generated by the electric power generator, the adjustment preferably being done as a function of at least one adjustment value, a second elementary control function (Tn), which makes it possible to adjust the duration of said control signal (S), preferably as a function of at least one adjustment value, and a third elementary control function (Cn), which makes it possible to adjust the cycle of the control signal (S), preferably as a function of at least one adjustment value, said program allowing a user to define the adjustment value(s) of the elementary control function(s).
[0032] More particularly, but not necessarily, said computer configuration program makes it possible to configure a control macro-function (M) also comprising a fourth elementary control function (Fn), which makes it possible to adjust the frequency of said control signal, preferably as a function of at least one adjustment value.
[0033] The invention also relates to a medium that can be read by a computer and on which a computer program as described above is stored.
BRIEF DESCRIPTION OF THE FIGURES
[0034] Other features and advantages of the invention will appear more clearly upon reading the detailed description below of several alternative embodiments of the invention, those alternatives being described as non-limiting and non-exhaustive examples of the invention and in reference to the appended drawings, in which:
[0035] FIG. 1 is a block diagram illustrating the architecture of a control system according to the invention;
[0036] FIGS. 2 to 5 are graphs illustrating example embodiments of elementary control functions F2, F3, A2, C2, respectively;
[0037] FIG. 6 illustrates an example implementation of a control macro-function.
DETAILED DESCRIPTION OF THE INVENTION
[0038] FIG. 1 shows one particular example of an electronic architecture of an electronic device 1 according to the invention, and which makes it possible to control a load 2 including at least one transducer (or actuator) which, depending on the case, may be of the piezoelectric, electrostrictive or magnetostrictive type.
[0039] In this text, the terms “piezoelectric or electrostrictive transducer” designate any device making it possible, in general, to transform electrical energy into mechanical energy through deformation of a material. In this text, “magnetostrictive transducer” designates any device generally making it possible to transform electromagnetic energy into mechanical energy through deformation of a material.
[0040] The load 2 and the associated piezoelectric, electrostrictive or magnetostrictive transducer(s) depend on the application and may be quite varied.
Example Applications
[0041] The electronic device 1 may be adapted and configured to control one or the other of the following loads 2 , the list of which has been provided below solely as example applications of the invention, and are non-limiting and non-exhaustive with respect to the invention.
Cleaning
[0042] The electronic device 1 is connected to one or more transducers that are fastened on the outer wall of a vat, which in turn is filled with a cleaning liquid. The electrical energy provided by the electronic device 1 is transformed by the transducer(s) into a vibrational energy that causes a cavitation phenomenon in the vat. This cavitation produces cleaning of the submerged parts.
[0043] Several electronic devices 1 can be used to supply a large-volume cleaning vat. In that case, the generators of the electronic devices 1 are synchronized with each other.
Welding—Cutting—Sonochemistry
[0044] The electronic device 1 is connected to a transducer. This transducer is generally equipped with a booster and a sonotrode whereof the end geometry is determinate of the use and of its application.
To weld materials, the shape of the sonotrode must hug the shape of the surface to be welded, For cutting, the sonotrode assumes the form of a vibrating strip, For sonochemistry, mixing, the sonotrode is often, but not always, cylindrical, and it is directly submerged in the liquid to be treated, For aerosol production, the end surface of the sonotrode makes it possible to spray the liquid that comes into contact with it; that service may be flat, curved, etc., For defoaming, the end surface of the sonotrode makes it possible to produce a very intense acoustic field in a gas (>160 dB).
[0050] The electronic device 1 is connected to a transducer and is adjusted so as to keep its control frequency at the working frequency, which is often the resonance or anti-resonance frequency of the transducer and the associated sonotrode. The energy transmitted to the transducer is converted into a vibrational energy that causes the desired phenomenon:
[0051] 1. For welding, heating,
[0052] 2. For cutting, slicing of the material,
[0053] 3. For sonochemistry, a very violent cavitation phenomenon,
[0054] 4. For aerosol production, a dispersion of the liquid in droplets,
[0055] 5. For defoaming, an acoustic field intense enough to break the foam bubbles during liquid filling in cans, etc.
Actuator Control
[0056] The electronic device 1 is connected to a transducer, which performs an actuator function, and the movement of which is proportional to a voltage delivered by the electronic device 1 . This movement is for example a static displacement if the delivered voltage is continuous; it is for example impulsive if the delivered command is a pulse, or for example has a more general shape proportional to the signal produced by the electronic device.
[0057] The induced effect aims to control the movement of a mechanical device coupled to the actuator (transducer), to produce a very low frequency vibration or induce a propulsion shock.
Control of Linear or Rotary Piezoelectric/Magnetostrictive Motors
[0058] To produce a linear displacement device, it is necessary to create a progressive wave in a device with finite dimensions. The device may be a bar or a ring. The progressive wave is created by superimposing two stationary waves with a 90° phase shift over time, and a 90° phase spatial shift. To produce such a system, it is necessary to have at least two ultrasonic transducers correctly positioned on the bar. Two electronic devices 1 are necessary to achieve that aim. The first device 1 powers a transducer with a controlled phase, and the second device 1 powers the second transducer with a 90° phase shift synchronized on the first electronic device. One example of this type of application is described in the article: “A survey of Ultrasonic Waves in Outer Transportation”, E. Murimi, J. Kihiu, G. Nyakoe and S. Mutuli.
[0059] The same principle is applicable to produce a rotary piezoelectric electric motor.
Architecture of the Electronic Control Device—FIG. 1
[0060] In reference to FIG. 1 , the electronic device 1 includes an electric power generator 10 , which, during operation, powers the load 2 , with an electric power signal S, designated in this text as “control signal”.
[0061] This electric power generator 10 is controlled automatically by a programmable electronic processing unit 11 .
[0062] The electronic device 1 also includes an electric power supply 12 , which includes:
a rectifying and filtering unit 120 making it possible to supply the electric power generator 10 with alternating current from the alternating current of the sector, and a unit 121 for converting the alternating current from the sector into a direct current to supply direct current to the programmable electronic processing unit 11 .
[0065] The electronic architecture of the electric power generator 10 is known in itself, and for example includes an H bridge 101 powering an adaptation network 102 , which for example includes a transformer, and which delivers the aforementioned control signal S. The H bridge is controlled by the programmable electronic processing unit 11 in the standard manner using a driver 103 . This particular electronic architecture of the electric power generator 10 is not limiting on the invention, and may be replaced by any electronic architecture making it possible to deliver an adjustable power signal (control signal S).
[0066] The programmable electronic processing unit 11 includes a digital processor 110 associated with a random-access memory (RAM) 111 and an electrically erasable read-only memory 112 , of the EEPROM type. The digital processor 110 may for example be a microprocessor, a microcontroller or a processor specialized in signal processing of the DSP type.
[0067] In the example embodiment of FIG. 1 , but optionally according to the invention, the digital processor 110 includes an input port 110 a that is connected to the matching network 102 , so as to perform real-time detection of the current I and the voltage V of the control signal S applied to the load 2 . In some cases, this detection makes it possible to produce a feedback loop of the control signal S relative to one or more instructions using the digital processor 110 .
[0068] In order to be able to communicate with the outside, the digital processor 110 also includes at least one communication port 110 b, which may for example be a slow serial input/output port of the RS485 type or an Ethernet port.
[0069] The communication port 110 b is in particular used to allow an external electronic processing unit 3 , for example an automaton or computer, to dialogue with the digital processor 110 , so as for example to allow the external electronic processing unit 3 to control the digital processor 110 , or to load or conversely recover data in the read-only memory 112 or random-access memory 111 .
[0070] The exchange of data with the outside on the communication port 110 b is preferably done through galvanic isolation 13 for example including optocouplers, in the standard manner.
Control Macro-Function—Elementary Control Functions
[0071] The operation of the electronic device 1 is advantageously based on the implementation of one or more control macro-functions, also shortened in this text to “macros”, which are each made up of elementary control functions, and which allow automatic adjustment by the processor 110 of the frequency, amplitude, duration and cycle of the control signal S.
[0072] Four families of elementary control functions are distinguished:
Frequency Family (F): This family includes all of the elementary control functions (F1, F2, F3, etc.) specific to the frequency of the control signal S, and outlined later. Each elementary control function from this family (F) makes it possible to adjust the frequency of the control signal, when it is executed automatically by the processor 110 . Amplitude Family (A): This family includes all of the elementary control functions (A1, A2, A3, etc.) specific to the amplitude of the control signal S, and outlined later. Each elementary control function from this family (A) makes it possible to adjust the amplitude of the control signal, when it is executed automatically by the processor 110 . Time Family (T): This family includes all of the elementary control functions (T1, T2, T3, etc.) specific to the notions of time (duration) of the generation of the control signal S, and outlined later. Each elementary control function from this family (T) makes it possible to adjust the duration of the control signal, when it is executed automatically by the processor 110 . Cycle Family (C): This family includes all of the elementary control functions (C1, C2, C3, etc.) specific to the notions of cycle for the generation of the control signal S and outlined later. Each elementary control function from this family (C) makes it possible to adjust the cycle of the control signal, when it is executed automatically by the processor 110 .
[0077] In general, each elementary control function is characterized by one or more adjustment parameters (ArgN), which are more or less complex, are specific to each elementary function, and allow the configuration of each elementary control function of a control macro-function. These adjustment parameters are also referred to in the rest of this text as “arguments”. For the operation of the electronic device 1 , each argument (ArgN) of an elementary control function of a macro-function M must be filled in with one or more specific adjustment values for that argument.
[0078] All of the elementary control functions are initially stored in the read-only memory 112 of the device 1 .
[0079] Different examples of elementary control functions will now be described non-limitingly and non-exhaustively with respect to the invention.
Examples of Elementary Control Functions in the Frequency Family (F)
F1: Forced Frequency
[0080] A frequency is imposed by the user, and the generator 10 applies that frequency with no feedback loop.
[0000] F 1=ƒ( Fc )
[0000]
Argument
Description
Unit
Precision
Fc
Frequency imposed on the system by the user
Hz
2
F2: Phase-Regulated Frequency
[0081] An optimal resonance frequency is determined in the authorized frequency range. The regulation is done using a regulating loop as a function of the estimated phase shift between the voltage V and the current I.
[0000] F 2=ƒ(Phase, initial frequency, F final, Tn )
[0000]
Argument
Description
Unit
Precision
Phase
Phase setting to be followed [−180°; 180°]
Degree
0.005
initial
Startup frequency of the regulation
Hz
2
frequency
Ffinal
Upper threshold frequency for frequency
Hz
2
regulation
Tn
Number of phase measurements used
1
to calculate the error (mean)
[0082] Let us consider the example of the following function F2, where we seek to regulate the frequency on a phase zero:
[0000] F 2=ƒ(0, 28000, 29000, Tn )
[0083] When the system is started up, the behavior of the frequency and the amplitude of the control signal S are illustrated in FIG. 2 .
F3: Modulated Frequency
[0084] A frequency variation dF is applied on a central frequency Fc. The modulation frequency is determined by Fm.
[0000] F 3=ƒ( Fc, dF, Fm )
[0000]
Argument
Description
Unit
Precision
Fc
Central frequency presumed to be optimal
Hz
2
dF
Frequency swing
Hz
1
Fm
Modulation frequency
Hz
0.01
[0085] Let us consider the example of the following function F3:
[0000] F 3=ƒ(28000, 1000, 0.50)
[0086] When the system is started up, the behavior of the frequency is illustrated in FIG. 3 .
4: Random Frequency
[0087] A random frequency sequence is authorized according to random function.
[0000] F exc= Fc±kΔƒ
[0088] The coefficient k is a random coefficient varying from 0 to 1. The sign of the function will also be random.
[0089] The function F4 will therefore be noted:
[0000] F 4=ƒ( Fc,Δƒ )
[0000]
Argument
Description
Unit
Precision
Fc
Central frequency
Hz
2
Δf
Maximum swing around the setpoint frequency
Hz
1
Examples of Elementary Control Functions from Amplitude Family (A)
A1: Forced Amplitude
[0090] An amplitude is imposed by the user; the generator 10 automatically applies that amplitude with no reaction.
[0000] A 1=ƒ( Po )
[0000]
Argument
Description
Unit
Precision
Po
Imposed amplitude
%
1
[0-100]
A2: Power-Regulated Amplitude
[0091] The power setting is imposed by the user. The current I and voltage V measurement on the transducer make it possible to calculate the actual power provided by the generator. This power is compared to the setting to keep the setting stable irrespective of the disruptions the transducer may undergo.
[0000]
Argument
Description
Unit
Precision
Pcsg
Power to be regulated [0-100]
%
1
[0092] Let us consider the example of the following function A2:
[0000] A 2 =f (80)
[0093] When the system is started up, the behavior of the power is illustrated in FIG. 4 .
Example of Elementary Control Function from the Time Family (T)
T1: TIME Elementary Function
[0094] The function T1 does not include any argument (adjustment value). When this function T1 is used in a macro-function, the control signal S is generated for an undetermined duration, until an external interruption of that signal is received by the generator 10 .
T2: Operating Duration
[0095] This elementary function makes it possible to adjust the operating duration of the generation of the control signal S.
[0000] T 2=ƒ(duration)
[0000]
Argument
Description
Unit
Precision
Duration
Operating duration before the automatic stop
sec
1
[0096] A duration equal to zero indicates an infinite duration. In that case, the device 1 will only stop as of an external setting or command.
Examples of Elementary Control Functions from the Cycle Family (C)
C1: CYCLE Elementary Function
[0097] The function F1 does not include any argument (adjusted value). When this function C1 is used in a macro-function, the control signal S is non-cyclic, i.e., is generated without repetition of a cycle.
C2: Cyclic Ratio (Ton/Ttotal)
[0098] At the end of the operating time, a stop time is determined by the Ton/Ttotal cyclic ratio.
[0000] C 2=ƒ( RC )
[0000]
Argument
Description
Unit
Precision
Rc
Cyclic ratio (Ton/Ttotal)
%
1
[0099] Let us consider the example of the following associated functions:
[0000] F 3=ƒ(28000, 1000, 0.50)
[0000] T 2=ƒ(60)
[0000] C 2= f (30)
[0100] The behavior of the amplitude of the signal S is illustrated in FIG. 5 .
Architecture and Depiction of a Control Macro-Function
[0101] FIG. 6 illustrates an example architecture of a control macro-function M, defined by the combination of different parameters:
[0102] Name: this is the identifier of the macro-function and must be unique and representative of the functionalities of the macro.
[0103] Description: This field is not essential, but makes it possible to provide the user with a quick and clear indication.
[0104] Frequency Family: Identification of the elementary function Fn of the family, among the functions specific to the family: F1, F2, F3, etc.
[0105] Amplitude family: Identification of the elementary function An of the family, among the functions specific to that family: A1, A2, A3, etc.
[0106] Time family: Identification of the elementary function Tn of the family, from among the functions specific to that family: T1, etc.
[0107] Cycle family: Identification of the elementary function Cn of the family, from among the functions specific to that family: C1, C2, C3, etc.
[0108] A control macro-function M can thus be written:
[0000] M=Fn (Arg1, Arg2, . . . )+ An (Arg1, Arg2, . . . )+ Tn (Arg1, Arg2, . . . )+ Cn (Arg1, Arg2, . . . ).
Example of Control Macro-Function
[0109] For example, in an industrial ultrasonic cleaning method, the user of the device 1 wishes to generate a wave train modulated at a fixed amplitude for a specific duration and to repeat that operation regularly.
[0110] During creation of the macro, it will therefore be necessary to assign that macro a name, a description, a Frequency function, an Amplitude function, a Time function and a Cycle function. Typically, the parameters of the macro are as follows:
[0000]
Parameters
Values
Name
SWEEP
Description
A frequency variation is authorized according to
a frequency deviation parameter (dF) relative to
the optimal central frequency.
Frequency
F3: Modulated frequency
Family
Amplitude
A1: Forced amplitude
Family
Time Family
T2: Operating duration
Cycle Family
C2: Cyclic ratio (Ton/Ttotal)
[0111] The macro is created. However, it is unusable in that state. It is now necessary to define the arguments specific to each function:
[0000]
Functions
Arguments
F3: Modulated frequency
Fc : Central operating frequency
dF: Frequency variation
Fm: Frequency modulation
A1: Forced amplitude
Pcsg: Setpoint power
T2: Operating duration
Tcsg: Operating duration
C2: Cyclic ratio
RC: Ton/Ttotal
[0112] We therefore obtain a macro that can be written:
[0000] SWEEP= F 3( Fc, dF, Fm )⊕ A 1( Pcsg )⊕ T 2( Tcsg )⊕ C 2( RC )
[0113] We therefore wish to use this macro at a central frequency of 30 kHz (±1000 Hz, modulated over 2 Hz) with an amplitude of 80% and over a duration of 10 minutes. Pause, then repeat the operation every forty minutes.
[0114] The macro will therefore be written:
[0000] SWEEP= F 3(30000, 1000, 2)⊕ A 1(80)⊕ T 2(600)⊕ C 2(25)
[0115] With:
F3(30000, 1000, 2) Corresponding to the modulated frequency A1(80) Corresponding to an amplitude of 80% T2(600) Corresponding to an operating duration of 10 minutes. C2(25) Corresponding to a cyclic ratio of 25% (to obtain 40 minutes)
Configuration and Usage Principle for Control Macro-Function
[0120] Initially, all of the available elementary control functions Fn, An, Tn, Cn are designed and loaded into the read-only memory 112 of the electronic device 1 by the manufacturer of the electronic device 1 . This loading of the elementary control functions into the memory 112 may be done using a computer 3 or equivalent means connected to the communication port 110 b of the device 1 ( FIG. 1 ).
[0121] In one preferred alternative embodiment, the control macro-functions Mn are also designed by the manufacturer of the electronic device 1 , and are for example stored on a server in a macro-function database.
[0122] To that end, the manufacturer of the electronic device 1 uses a specific computer program to build control macro-functions, which is suitable for being executed by electronic processing means, such as a microcomputer 3 . This control macro-function building program makes it possible, when executed, for a user of the program to build control macro-functions (M) using elementary control functions from the aforementioned function families F, A, T, C.
[0123] In order to adapt the operation of the electronic control device 1 to the particular load 2 related to its specific application, the user of the electronic device 1 can, using a specific configuration program, which can be executed on a microcomputer 3 and has been provided to it by the manufacturer of the device 1 :
access the control macro-function database, either locally, or remotely via a telecommunications network, of the Internet type, and configure one or more control macro-functions to which it has access. Configuring the control macro-function consists of setting the adjustment value(s) of the arguments ArgN specific to each elementary control function making up the control macro-function.
[0126] Once the configuration step is complete, each control macro-function Mn that has been configured is stored locally in a backup file, for example on the hard drive of the user's microcomputer, while being allocated to a given electronic device 1 . The backup file contains the elementary functions allocated to the macro as well as all of the arguments filled in by the user.
[0127] Next, the user connects his microcomputer to the communication port 110 b of the device 1 and loads the control macro-function(s) that have been configured into the read-only memory 112 of the device 1 . During this step, the arguments ArgN of the elementary functions are not transferred.
[0128] More particularly, in the read-only memory 112 , an area dedicated to the macros exists, like that shown below:
[0000]
@
Name
Comments
Min
Max
0x0514
No. of macros configured
0
31
0x0515
No. of active macros
0: No active macros
0
31
0x0516
Macro 1 (Fn and An)
Bits 0 to 7: Frequency
1
255
function no.
Bits 8 to 15: Amplitude
1
255
function no.
0x0517
Marco 1 (Tn and Cn)
Bits 0 to 7: Time
1
255
function no.
Bits 0 to 7: Cycle
1
255
function no.
. . .
0x0552
Marco 31 (Fn and An)
Bits 0 to 7: Frequency
1
255
function no.
Bits 8 to 15: Amplitude
1
255
function no.
0x0553
Marco 31 (Tn and Cn)
Bits 0 to 7: Time
1
255
function no.
Bits 8 to 15: Cycle
1
255
function no.
[0129] The electronic device 1 can thus contain, in read-only memory 112 , one or more configured control macro-functions M1, M2, . . . , Mn.
[0130] Next, to make the electronic device operate, several scenarios may occur.
[0131] In a first autonomous operating mode, the user's microcomputer 3 being connected to the communication port 110 b, the user views the control macro-function(s) stored in random access memory 111 on the screen of his microcomputer, activates only one macro-function M from among the set of available macro-functions, and transfers the arguments (Arg1, . . . ) of the elementary functions of the control macro-function that are stored in the backup file on the hard drive of the microcomputer into the read-only memory 112 of the electronic device 1 .
[0000] As an example, let us consider the following macro:
[0000] SWEEP= F 3(28000, 1000, 0.50)⊕ A 1(80)⊕ T 1(600)⊕ C 2(25)
[0000] During the transfer of the macro to the electronics, the EEPROM 112 of the peripheral will have the following information:
[0000]
Number of usable macros
1
Number of the active macro
1
Frequency
Amplitude
Time
Cycle
MACRO 1
3
1
1
2
MACRO 2
0
0
0
0
. . .
0
0
0
0
MACRO 31
0
0
0
0
[0132] Once the control macro-function M is activated, the electronic control device 1 can operate autonomously, the processor 110 being programmed to control the H bridge 101 of the generator 10 from the active control macro-function M.
[0133] In another controlled operating mode, a programmable automaton or equivalent means is connected to the communication port 110 b of the electronic device 1 and automatically controls the device 1 by automatically activating a control macro-function at the same time as a function of a program executed by the automaton.
[0134] In the aforementioned example embodiments, the macro-functions are built from four families (F, A, T, C) of elementary control functions. In another alternative embodiment, in particular when the transducer does not generate a vibrational movement, but is used for example to control the movement of a member or to generate a mechanical impact, the Frequency family F is not essential, and the macro-functions may be built from three families (A, T, C).
[0135] In the context of the invention, the arguments Arg 1 , Arg 2 , . . . , of one or more control functions are not necessarily constant over time, but can also make up variables that evolve over time as a function of a programmed control law, in particular being able to take into account the evolution of the system that is controlled by the electronic control device into account.
[0136] This design in the form of control macro-functions made up of configurable elementary functions allows the user of the electronic device 1 to develop and hone a given application quickly and easily, by configuring the universal electronic device 1 so as to adapt specifically to the piezoelectric, electrostrictive or magnetostrictive transducer of the application. This new design also allows the manufacturer of the electronic device 1 to configure and upgrade the device 1 easily, by loading new elementary control functions into the memory 112 and/or by modifying the existing elementary control functions.
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The electronic device ( 1 ) for controlling comprises an electric power generator ( 10 ) suitable for supplying at least one piezoelectric, electrostrictive or magnetostrictive transducer ( 2 ), with a control signal (S), electronic controlling means ( 11 ) capable of automatically controlling the electric power generator by using a control macro-function (M), and an electronic memory ( 112 ) in which the following are stored: a first family (A) of control functions comprising one or a plurality of different elementary control functions (An), making it possible to adjust the amplitude of the control signal (S), a second family (T) of control functions comprising one or a plurality of different elementary control functions (Tn), making it possible to adjust the duration of the control signal (S), a third family (C) of control functions comprising a plurality of different elementary control functions (Cn), making it possible to adjust the control signal (S) cycle, at least said control macro-function (M), which is made up of the assembly of at least three elementary control functions chosen respectively from among the three families of control functions (A, T, C) recorded in the memory.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application if a continuation of U.S. patent application Ser. No. 12/255,638 filed Oct. 21, 2008, and published Feb. 19, 2009, as United States Patent Publication 2009/0044753, which is a divisional application of U.S. patent application Ser. No. 11/689,278, filed Feb. 28, 2007, and patented Apr. 7, 2009, as U.S. Pat. No. 7,514,125, which claims benefit of U.S. provisional patent application Ser. No. 60/805,706 (APPM/011269L), filed Jun. 23, 2006, all of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the invention as recited by the claims generally relate to an article having a protective coating for use in a semiconductor processing chamber and a method of making the same.
[0004] 2. Description of the Related Art
[0005] Integrated circuits have evolved into complex devices that can include millions of transistors, capacitors and resistors on a single chip. The evolution of chip designs continually requires faster circuitry and greater circuit density that demand increasingly precise fabrication techniques and processes. One fabrication process frequently used is plasma enhanced chemical vapor deposition (PECVD).
[0006] PECVD is generally employed to deposit a thin film on a substrate or a semiconductor wafer. PECVD is generally accomplished by introducing a precursor gas or gases into a vacuum chamber. The precursor gas is typically directed through a showerhead typically fabricated from aluminum situated near the top of the chamber. Plasma is formed in the vacuum chamber. The precursor gas reacts with the plasma to deposit a thin layer of material on the surface of the substrate that is positioned on a substrate support. Purge gas is routed through holes in the support to the edge of the substrate to prevent deposition at the substrate's edge that may cause the substrate to adhere to the support. Deposition by-products produced during the reaction are pumped from the chamber through an exhaust system.
[0007] One material frequently formed on substrates using a PECVD process is amorphous carbon. Amorphous carbon is used as a hard mask material in semiconductor application because of its chemical inertness, optical transparency, and good mechanical properties. Precursor gases that may be used to form amorphous carbon generally include a hydrocarbon, such as propylene and hydrogen.
[0008] The etch selectivity of amorphous carbon films has been correlated to film density. Ion bombardment densification of amorphous carbon films is one method of increasing the etch selectivity of an amorphous carbon film, however, ion-bombardment induced film densification invariably leads to a proportional increase in the compressive film stress, both on the showerhead of the PECVD chamber and the substrate. Highly compressive carbon residues on the showerhead poorly adhere to the showerhead surfaces, producing flakes and particles during prolonged durations of deposition. The stray carbon residue builds on the showerhead and may become a source of contamination in the chamber. Eventually, the stray carbon residue may clog the holes in the showerhead that facilitate passage of the precursor gas therethrough thus necessitating removal and cleaning of the showerhead or possibly replacement.
[0009] Therefore, there is a need for an apparatus or method that reduces formation of loose carbon deposits on aluminum surfaces in semiconductor processing chambers.
SUMMARY
[0010] Embodiments of the present invention as recited by the claims generally provide an apparatus and method that reduces formation of loose carbon deposits on aluminum surfaces and reduces in-film particle formation in semiconductor processing chambers.
[0011] An article having a protective coating for use in semiconductor applications and methods for making the same are provided. In certain embodiments, a method of coating an aluminum surface of an article utilized in a semiconductor processing chamber is provided. The method comprises providing a processing chamber, placing the article into the processing chamber, flowing a first gas comprising a carbon source into the processing chamber, flowing a second gas comprising a nitrogen source into the processing chamber, and depositing a coating material on the aluminum surface. In certain embodiments, the coating material comprises a nitrogen containing amorphous carbon layer. In certain embodiments, the coated article is a showerhead configured to deliver a gas to the processing chamber.
[0012] In certain embodiments, a method of reducing contaminants in a layer deposited in a semiconductor processing chamber containing an aluminum surface is provided. The method comprises providing a semiconductor processing chamber, placing a substrate into the processing chamber, flowing a first gas comprising a carbon source into the processing chamber, flowing a second gas comprising a hydrogen source into the processing chamber, forming a plasma from an inert gas in the chamber, and depositing a layer on the substrate.
[0013] In certain embodiments, an article for use in a semiconductor processing chamber is provided. The article comprises a showerhead, a support pedestal, or a vacuum chamber body having an aluminum surface and a coating material comprising a nitrogen containing amorphous carbon material applied on the aluminum surface in a plasma enhanced chemical vapor deposition process.
[0014] In certain embodiments a showerhead having an aluminum surface coated with a nitrogen containing amorphous carbon material is provided. The nitrogen containing amorphous carbon material is applied to the showerhead by a method comprising flowing a first gas comprising a carbon source into the processing chamber, flowing a second gas comprising a nitrogen source into the processing chamber, forming a plasma in the chamber, and depositing the nitrogen containing amorphous carbon material on the aluminum surface.
[0015] In certain embodiments, a showerhead configured to deliver gas to a semiconductor processing chamber is provided. The showerhead comprises an upper surface, a lower surface comprising aluminum, wherein the lower surface has a surface roughness of between about 30 nm and about 50 nm, and a plurality of openings formed between the upper surface and the lower surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A more particular description of the invention, briefly summarized above, may be had by reference to certain embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain embodiments and are therefore not to be considered limiting of its scope.
[0017] FIG. 1 is a sectional view of a PECVD chamber assembly;
[0018] FIG. 2 is a sectional view of a showerhead used in the PECVD chamber assembly of FIG. 1 ;
[0019] FIG. 3 depicts an exemplary flow diagram of a method of coating an aluminum surface of an article;
[0020] FIG. 4 is a graph demonstrating the effect of an exemplary coating material on in-film particle performance of 10 kÅ thick Low k amorphous carbon layer;
[0021] FIG. 5A is a sectional view of a showerhead before the showerhead is treated to increase surface roughness;
[0022] FIG. 5B is a sectional view of a showerhead with a roughened surface;
[0023] FIG. 5C is a sectional view of a showerhead with carbon residue attached to the roughened surface;
[0024] FIG. 6 illustrates a graph demonstrating the effect of faceplate roughness on the in-film particle performance of 10 kÅ thick Low k amorphous carbon layer; and
[0025] FIG. 7 illustrates a graph demonstrating the effect of H 2 dilution on the in-film particle performance of 10 kÅ thick Low k amorphous carbon layer.
[0026] To facilitate understanding, identical reference numerals have been used, wherever possible, to designate identical elements that are common to the figures. It is contemplated that elements and/or process steps of one or more embodiments may be beneficially incorporated in one or more other embodiments without additional recitation.
DETAILED DESCRIPTION
[0027] In certain embodiments, a processing system having coated aluminum surfaces that are advantageous for the deposition of amorphous carbon and other films is disclosed.
[0028] FIG. 1 is a sectional view of an exemplary PECVD chamber assembly 100 . The PECVD chamber may be any plasma enhanced CVD chamber or system including systems such as the CENTURA ULTIMA HDP-CVD™ system, PRODUCER APF PECVD™ system, PRODUCER BLACK DIAMOND™ system, PRODUCER BLOK PECVD™ system, PRODUCER DARC PECVD™ system, PRODUCER HARP™ system, PRODUCER PECVD™ system, PRODUCER STRESS NITRIDE PECVD™ system, and PRODUCER TEOS FSG PECVD™ system, available from Applied Materials, Inc. of Santa Clara, Calif. An exemplary PRODUCER® system is further described in commonly assigned U.S. Pat. No. 5,855,681, issued Jan. 5, 1999, which is herein incorporated by reference.
[0029] Plasma enhanced chemical vapor deposition (PECVD) techniques generally promote excitation and/or disassociation of the reactant gases by the application of an electric field to a reaction zone near the substrate surface, creating a plasma of reactive species immediately above the substrate surface. The reactivity of the species in the plasma reduces the energy required for a chemical reaction to take place, in effect lowering the required temperature for such PECVD processes.
[0030] FIG. 1 is a sectional view of a PECVD chamber assembly 100 . The chamber assembly 100 has a sidewall 105 , a ceiling 106 , and a base 107 which enclose a processing region 121 . A substrate pedestal 115 , which supports a substrate 120 , mounts to the base 107 of the chamber assembly 100 . A backside gas supply (not shown) furnishes a gas, such as helium, to a gap between the backside of the substrate 120 and the substrate pedestal 115 to improve thermal conduction between the substrate pedestal 115 and the substrate 120 . In certain embodiments, the substrate pedestal 115 is heated and/or cooled by use of embedded heat transfer fluid lines (not shown), or an embedded thermoelectric device (not shown), to improve the plasma process results on the substrate 120 surface. A vacuum pump 135 controls the pressure within the process chamber assembly 100 , typically holding the pressure below 0.5 milliTorr (mT). A gas distribution showerhead 110 can consist of a gas distribution plenum 140 connected to a gas supply 125 and can communicate with the process region over the substrate 120 through plural gas nozzle openings 142 . The showerhead 110 , made from a conductive material (e.g., anodized aluminum, etc.), acts as a plasma controlling device by use of a first impedance match element 175 A and a first RF power source 180 A. A bias RF generator 162 can apply RF bias power to the substrate pedestal 115 and substrate 120 through an impedance match element 164 . A controller 170 is adapted to control the impedance match elements (i.e., 175 A and 164 ), the RF power sources (i.e., 180 A and 162 ) and certain other aspects of the plasma process. In certain embodiments dynamic impedance matching is provided to the substrate pedestal 115 and the showerhead 110 by frequency tuning and/or by forward power serving.
[0031] In operation, the substrate 120 can be secured to the substrate pedestal 115 by providing a vacuum therebetween. The temperature of the substrate is elevated to a pre-determined process temperature by regulating thermal transfer to the substrate pedestal 115 by, for example, a heating element (not shown). During the deposition process, the substrate is heated to a steady temperature typically between about 200° C. and 700° C.
[0032] Gaseous components, which in certain embodiments may include propylene and hydrogen, can be supplied to the process chamber assembly 100 via the gas nozzle openings 142 in showerhead 110 . A plasma is formed in the process chamber assembly 100 by applying RF power to a gas source such as argon or nitrogen. The gaseous mixture reacts to form a layer of amorphous carbon, for example Advanced Patterning Film or “APF” available from Applied Materials, Inc. of Santa Clara, Calif., on the surface of the substrate 120 .
[0033] FIG. 2 is a sectional view of an exemplary showerhead 110 . As shown in FIG. 2 , the showerhead can comprise an upper surface 215 and a lower surface 205 . A plurality of gas nozzle openings 142 can be formed between the lower surface 205 and the upper surface 215 . In certain embodiments, the coating material 210 is disposed on the lower surface 205 of the showerhead 110 . The coating material 210 can be applied before final assembly of the process chamber assembly 100 . The coating material 210 can also be applied to other parts of the showerhead 110 such as the face plate and the gas distribution plate. However, in certain embodiments, the coating material 210 can be applied to the showerhead 110 after final assembly of the process chamber assembly 100 . Optionally, the coating material 210 can be applied to other aluminum surfaces within the process chamber assembly 100 , for example, the chamber 100 itself and the support pedestal 115 . In certain embodiments, it may be necessary to periodically reapply the coating material 210 to the showerhead 110 or other aluminum surface. In certain embodiments, aluminum surface is cleaned prior to reapplication of the coating material 210 .
[0034] In certain embodiments, the coating material 210 comprises a layer of nitrogen containing amorphous carbon or other material that inhibits flaking of carbon residue from the showerhead 110 . The thickness of the coating material 210 is sufficient to provide a “sticky” seasoned layer and is typically between about 500 Å and about 3000 Å, such as between about 1000 Å and about 2000 Å, for example about 1500 Å. The coating material 210 functions as an adhesion promoting layer between the bare lower surface 205 of the showerhead 110 and the carbon residues deposited on the showerhead 110 during the amorphous carbon deposition. Thus the coating material 210 adheres to aluminum surfaces as well as amorphous carbon surfaces. Since nitrogen can bond with carbon as well as aluminum surfaces, it can create a “sticky” seasoned layer. In certain embodiments, the seasoned layer can be predominantly carbon which can allow forthcoming amorphous carbon residues to adhere to the showerhead and thereby can inhibit flaking or fall-on particles.
[0035] FIG. 3 depicts a flow diagram 300 of certain embodiments of a method of coating an aluminum surface of an article. For example, in step 310 , a processing chamber is provided. In step 320 , the article is placed into the processing chamber. In step 330 , a first gas comprising a carbon source is flowed into the processing chamber. In step 340 , a second gas comprising a nitrogen source is flowed into the processing chamber. In step 350 , a plasma is formed in the chamber. In step 360 , a coating material is deposited on the aluminum surface.
[0036] Typical carbon sources include hydrocarbon compounds with the general formula C x H y where x has a range of between 2 and 10 and y has a range of between 2 and 22. For example, propylene (C 3 H 6 ), propyne (C 3 H 4 ), propane (C 3 H 8 ), butane (C 4 H 10 ), butylene (C 4 H 8 ), butadiene (C 4 H 6 ), acetelyne (C 2 H 2 ), pentane, pentene, pentadiene, cyclopentane, cyclopentadiene, benzene, toluene, alpha terpinene, phenol, cymene, norbornadiene, as well as combinations thereof, may be used as the hydrocarbon compound. Liquid precursors may be used to deposit amorphous carbon films. The use of liquid precursors in the deposition of amorphous carbon films is further discussed in United States Patent Application Publication No. 2005/0287771, published Dec. 29, 2005, entitled LIQUID PRECURSORS FOR THE CVD DEPOSITION OF AMORPHOUS CARBON FILMS, which is herein incorporated by reference to the extent it does not conflict with the current specification. These liquid precursors include, but are not limited to, toluene, alpha terpinene (A-TRP), and norbornadiene (BCHD).
[0037] Similarly, a variety of gases such as hydrogen (H 2 ), nitrogen (N 2 ), ammonia (NH 3 ), or combinations thereof, among others, can be added to the gas mixture, if desired. Argon (Ar), helium (He), and nitrogen (N 2 ) can be used to control the density and deposition rate of the amorphous carbon layer.
[0038] The carbon source compound may be introduced into the chamber at a flow rate of between about 200 sccm and about 2000 sccm, such as between about 1,500 sccm and about 2,000 sccm, for example, 700 sccm. The nitrogen source may be introduced into the chamber at a flow rate of between about 100 sccm and about 15,000 sccm, such as between about 5,000 sccm and about 10,000 sccm, for example, 8,000 sccm. Optionally, a carrier gas can be introduced into the chamber at a flow rate of between about 0 sccm and about 20,000 sccm. The carrier gas may be nitrogen gas or an inert gas. In certain embodiments, the flow rates are chosen such that the coating material is predominately carbon. For example, the carbon source compound may be introduced into the chamber at a first flow rate, and the nitrogen source compound may be introduced into the chamber at a second flow rate such that the ratio of the second flow rate to the first flow rate is between about 50:1 and about 1:1, such as between about 10:1 and about 1:1, for example, about 7:1. In certain embodiments, the carbon source compound is propylene and the nitrogen source is nitrogen.
[0039] In certain embodiments, during deposition of the nitrogen containing amorphous carbon layer, the substrate can be typically maintained at a temperature between about 200° C. and about 700° C., preferably between about 250° C. and about 350° C., such as about 300° C. In certain embodiments, a RF power level of between about 20 W and about 1,600 W, for example, about 1,000 W, for a 300 mm substrate is typically used in the chamber. The RF power can be provided at a frequency between about 0.01 MHz and 300 MHz, for example, 13.56 MHz. In certain embodiments, the RF power can be provided to a gas distribution assembly or “showerhead” electrode in the chamber. In certain embodiments, the RE power may be applied to a substrate support in the chamber. In certain embodiments, the RF power may be provided at a mixed frequency, such as at a high frequency of about 13.56 MHz and a low frequency of about 350 kHz. The RF power may be cycled or pulsed and continuous or discontinuous.
[0040] In certain embodiments, the spacing between the showerhead and support pedestal during the deposition of the nitrogen containing amorphous carbon layer may be between about 280 mils and about 1,500 mils, for example, 400 mils, and the pressure in the chamber may be between about 1 Torr and about 10 Torr, for example, 7 Torr.
[0041] FIG. 4 is a graph demonstrating the effect of certain embodiments of the coating material on in-film particle performance of 10 kÅ thick Low k amorphous carbon. FIG. 4 shows the effect of a nitrogen amorphous carbon layer of approximately 1,500 Å thick deposited on the showerhead prior to the bulk Low k amorphous carbon deposition. The exemplary coating material was deposited using the following conditions: a substrate temperature of 300° C., a chamber pressure of 7 Torr, a spacing of 400 mils, a nitrogen flow rate of 8,000 sccm, a propylene flow rate of 700 sccm, a RF power level of 1,000 W, a deposition rate of 2,100 Å/min. These conditions produced a nitrogen containing amorphous carbon layer with a refractive index of 1.69, a light absorption coefficient of 0.02, and a stress of −80 MPa.
[0042] Still referring to FIG. 4 , the exemplary Low k amorphous carbon layer was deposited on wafer 1 without the benefit of the nitrogen containing amorphous carbon layer. The exemplary Low k amorphous layer was deposited on wafers 2 - 4 with the benefit of the nitrogen containing amorphous carbon layer. The results show a significant reduction in in-film adders or contaminants, represented by A 1 and A 2 , for the exemplary Low k amorphous carbon layers deposited on wafers 2 - 4 .
[0043] In certain embodiments a method for improving the adhesion strength of the lower surface 205 of the showerhead 110 is provided. FIG. 5A is a sectional view of the showerhead 110 before the showerhead 110 is treated to increase surface roughness. The showerhead 110 can comprise an upper surface 215 and a lower surface 205 . A plurality of gas nozzle openings 142 can be formed between the lower surface 205 and the upper surface 215 . In certain embodiments, this method increases the surface roughness of the lower surface 205 of the showerhead 110 . In certain embodiments, this method may also be used to increase the surface roughness of other parts of the chamber 100 . For example, in certain embodiments this method increases the root mean square (“RMS”) roughness of the lower surface 205 of the showerhead 110 from about 20 nm to between about 30 nm and about 50 nm, for example, about 40 nm. FIG. 5B is a sectional view of the showerhead 110 with a roughened surface 502 . Roughening of the lower surface 205 to produce roughened surface 502 may be performed by a variety of methods known to those of skill in the art. For example, two such methods of roughening can be achieved by physically bombarding the showerhead with small metallic balls, also known as a “bead blasting process,” and/or application of various chemical treatments known in the art.
[0044] FIG. 5C is a sectional view of a showerhead with carbon residue 504 securely attached to the roughened surface 502 . In certain embodiments, the “bead blasting process” can provide a textured and roughened surface 502 that enhances the adherence of carbon residue 504 to the roughened surface 502 of the showerhead 110 . In bead blasting, beads are propelled toward the surface by air at a pressure that is suitably high to roughen the surface. The beads may comprise a material having a hardness higher than that of the underlying structure to allow the beads to erode and roughen the lower surface 205 of the showerhead 110 to form a roughened surface 502 . Suitable bead materials include for example, aluminum oxide, glass, silica, or hard plastic. In certain embodiments, the beads comprise a grit of aluminum oxide having a mesh size selected to suitably grit blast the surface, such as for example, a grit of alumina particles having a mesh size of about 200. The bead blasting may take place in, for example, a bead blaster, comprising an enclosed housing.
[0045] In certain embodiments, FIG. 6 illustrates a graph demonstrating the effect of faceplate roughness on the in-film particle performance of 10 kÅ thick Low k amorphous carbon layer. For example, FIG. 6 compares the In-Film adders for a 10 kÅ thick Low k amorphous carbon layer deposited in a chamber containing an exemplary bead-blasted faceplate versus a standard faceplate. In certain embodiments, the exemplary bead-blasted faceplate can have a roughness of 40 nm where the standard faceplate has a roughness of 10 nm. For example the results show a significant reduction of in-film adders/contaminants for 10 kÅ thick Low k amorphous carbon deposited in a chamber containing an exemplary bead-blasted faceplate with a roughness of 40 nm versus a chamber containing a standard faceplate with a roughness of 10 nm. These results demonstrate that an increase in the surface roughness of the showerhead increases the adhesion strength between the showerhead and carbon residues thus reducing the presence of in-film adders in the deposited Low k amorphous carbon layer.
[0046] In certain embodiments, a method of reducing the presence of in-film adders is provided. The method comprises the addition of H 2 as a dilution gas during the bulk deposition process. In certain embodiments, this method may be used with deposition processes described in United States Patent Application Publication No. 2005/0287771, published Dec. 29, 2005, entitled LIQUID PRECURSORS FOR THE CVD DEPOSITION OF AMORPHOUS CARBON FILMS and U.S. patent application Ser. No. 11/427,324, filed Jun. 28, 2006, entitled METHOD FOR DEPOSITING AN AMORPHOUS CARBON FILM WITH IMPROVED DENSITY AND STEP COVERAGE which are herein incorporated by reference to the extent they do not conflict with the current specification. In certain embodiments, the addition of H 2 has been shown to significantly reduce the in-film particles. It is believed that several mechanisms play a role in this phenomenon. For example, hydrogen species can passivate the gas phase CH x species, thereby limiting the growth of these radicals into potential particle nuclei. Additionally, for example, the addition of H 2 may lead to a widening of the plasma sheath at the electrode surfaces, thus leading to a reduction in the momentum of the ions bombarding the electrodes.
[0047] In certain embodiments, FIG. 7 illustrates a graph demonstrating the effect of H 2 dilution on the in-film particle performance of an exemplary 10 kÅ thick Low k amorphous carbon layer. Deposition for the first sample, represented by “A,” was performed with an exemplary argon flow rate of 8,000 sccm and an exemplary helium flow rate of 400 sccm. Deposition for the second sample, represented by “B,” was performed with an exemplary argon flow rate of 7,000 sccm and an exemplary hydrogen flow rate of 1,000 sccm. Deposition for the third sample, represented by “C,” was performed with an exemplary argon flow rate of 5,000 sccm and an exemplary hydrogen flow rate of 2,000 sccm. Deposition for the fourth sample, represented by “D,” was performed with an exemplary argon flow rate of 5000 sccm and an exemplary hydrogen flow rate of 3,000 sccm. The results show that an increase in the addition of H 2 as a dilution gas can yield a decrease in in-film adders.
[0048] While the foregoing is directed to certain embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
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An article having a protective coating for use in semiconductor applications and methods for making the same are provided. In certain embodiments, a method of coating an aluminum surface of an article utilized in a semiconductor processing chamber is provided. The method comprises providing a processing chamber; placing the article into the processing chamber; flowing a first gas comprising a carbon source into the processing chamber; flowing a second gas comprising a nitrogen source into the processing chamber; forming a plasma in the chamber; and depositing a coating material on the aluminum surface. In certain embodiments, the coating material comprises an amorphous carbon nitrogen containing layer. In certain embodiments, the article comprises a showerhead configured to deliver a gas to the processing chamber.
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BACKGROUND
[0001] I. Field of the Invention
[0002] The present invention is generally directed to a method and apparatus for voltage upconverting. More particularly, the present invention is directed to a method and apparatus for providing a miniaturized, flexible high voltage up-converter. Aspects of the invention are particularly useful in providing an apparatus comprising a plurality of up-converting modules while also allowing the apparatus to maintain a desired degree of flexibility. However, certain aspects of the invention may be equally applicable in other scenarios as well.
[0003] II. Description of Related Technology
[0004] In conventional angioplasty operations, a stent is inserted into a patient's artery that may be occluded or constricted by plaque. These stents allow a surgeon to, via in-vivo stent manipulation and guidance, enter the patient's body and keep the occlusion unrestricted. If, subsequently, the stent occluded again, irradiation of the constricted stent area may be required. Alternatively, catheters may be used to irradiate a cancerous growth. Irradiation occurs with radioactive seeds emitting beta or gamma rays. To produce these beta or gamma rays, however, the catheters have to be provided with means allowing those radioactive seeds to travel to the site where treatment is needed. These seeds are highly radioactive and irradiate the entire length of the artery from insertion point to the treatment site. Once removed from the shielding container, they pose a health risk to the patient and the medical professionals administering treatment. To solve some of these problems associated with the radioactive seeds, it is desirable to provide an X-ray generating device that generates an X-ray source near the desired area and the X-ray dose can be generated in-vivo at will. Because the radiation must be produced at the site of interest (i.e., at the obstructed artery or the cancerous growth), this X-ray tube is typically located at a distal end of the stent or catheter.
[0005] Under ordinary operation, these X-ray tubes require a high degree of power (voltage) to operate. For example, U.S. Pat. No. 5,090,043 entitled “X-ray Micro-Tube and Method of Use in Radiation Oncology” to Parker et al. teaches the use of an apparatus and method for the treatment of a patient having a tumor.
[0006] Parker et al. teaches using an X-ray generating source positioned at a location in close proximity to site or application (e.g., an artery, a vein, or a tumor). The X-ray generating source is operable at a voltage level in the range of approximately 10-60 kilo-electron volts (keV) to thereby enhance absorption of the generated X-rays by the tumor and minimizing the side effects of radiation therapy on the patient normal tissue.
[0007] Therefore, to provide the necessary voltage and power to certain types of miniature X-ray tubes, approximately 10-60 keV are required. For treatment of occluded stents, approximately 20 kV are sufficient. To provide this high level of voltage at a distal end of a catheter, the power must be provided along the entire catheter cable to the catheter distal end. Proposed catheters, however, are provided with a lengthy high voltage power cable. For example, a proposed catheter high voltage cable is typically on the order of three feet in length. Therefore, a dangerous situation arises where the peak voltage of 20 kV must traverse along the entire length of the catheter cable and then along the length of the catheter to eventually reach the X-ray unit.
[0008] Providing this peak voltage along a high voltage cable feeding the catheter and then also running the entire length of the catheter poses certain dangerous operating conditions. For example, storing such a large amount of energy can accidentally and/or inadvertently discharge and harm or fatally injure a patient and/or physician. Flashover between the high voltage components and an exterior housing of the catheter (an electrical ground) could harm or even kill the patient, the administering physician, and/or others involved in the in-vivo operation (e.g., members of the operating staff). Flashover occurs where there is leakage between the outside grounded and the inside high-voltage and this leakage if followed by a dielectric breakdown. This flashover concern exists along the entire cable length.
[0009] Therefore, because of a requirement for a long high voltage cable, most proposed miniature X-ray tube catheter systems behave as essentially a very large, charged capacitor.
[0010] There is, therefore, a general need to be able to reduce the necessity of a lengthy high voltage cable. There is also a general need to reduce a high voltage system's overall capacitance, and therefore potential flashover. These general needs should also be met while also being able to generate a high enough voltage for X-ray application at the point of observation or X-ray application.
[0011] Aside from these high voltage breakdown and capacitance concerns, there is also a maneuvering or manipulating concern associated with catheters containing miniaturized X-ray tubes. For example, because such medical devices may be used in a variety of applications (e.g., angioplasty, tumor irradiation, etc.), the catheter containing certain components must be flexible enough so that during an in-vivo operation, a user of the device (i.e., a surgeon) can maneuver and/or manipulate the subject catheter so as to manipulate or guide the X-ray unit along an artery to accurately position the catheter at a desired location. Because certain proposed miniature X-ray tubes have been large (larger than 2.5 mm in diameter), there is a further need for a flexible, guidable device comprising a X-ray tube device having a diameter less than 2.5 mm. It is believed that an ideal X-ray tube for angioplasty procedures has a diameter ranging from 0.5 to 1.0 mm. Other diameter sizes could also be desired depending on the application of the X-ray tube.
[0012] Even though the same proposed concepts may describe a relatively compact voltage source, the dimensions of such voltage sources are large, often on the scale of inches. For example, the voltage source disclosed in U.S. Pat. No. 4,241,360 discloses a voltage source having a size on the order of 0.5 inches in length (12 mm) and 0.2 inches wide (5 mm). For medical applications, and especially for catheters that are inserted inside a body, further miniaturization is desired. In addition, where a voltage source is used in a catheter or other in-vivo applications, the catheter and hence the voltage source must have some degree of flexibility and maneuverability.
[0013] There is also a need to provide a miniaturized power source that reduces the risk to the patient by minimizing the discharge power and while also maintaining catheter flexibility. There is also a general need to provide a power source that can be guidable through difficult passageways and provide a source of power at difficult to reach areas.
SUMMARY
[0014] According to one exemplary arrangement, an apparatus for up-converting an initial voltage includes a first photodiode module. A first photon source is optically coupled to the first photodiode module to a light source. The first module up-converts the initial voltage to a first up-converted voltage. A second photodiode module receives the first up-converted voltage from the first photodiode module and a photon source coupled to the second photodiode module to the source. The second photodiode module up-converts the first up-converted voltage to a second up-converted voltage.
[0015] According to another exemplary arrangement, a method of voltage up-converting includes the steps of electrically coupling a first up-converting module to a second module and optically coupling a photon source to the first and the second modules. The photon source generates at the first up-converting module an up-converted voltage. This upconverted voltage is provided to the second up-converting module from the first up-converting module and the source is utilized to up-convert the first voltage.
[0016] In another arrangement, a miniaturized, flexible voltage up-converting instrument includes an X-ray generating source insertable into a body of a patient to a location in close proximity to a desired point of X-ray application. A first modular voltage up-converter is coupled to the generating source. An upconverted voltage is applied to the source to generate a desired X-ray dose at a desired point of application.
[0017] In yet an alternative arrangement, a method of fabricating a voltage up-converter is provided. The method includes the steps of:
[0018] providing a substrate containing a thin layer of silicon conducting material;
[0019] performing an initial n − 0 type of ion implantation region, said region defining an initial photodiode pattern on a surface of said substrate;
[0020] fabricating a plurality of p + type ion implantation regions along said photodiode pattern;
[0021] fabricating a second plurality of n + ion implantation regions along said photodiode pattern; and
[0022] providing an oxide layer along a top surface of said photodiode pattern.
[0023] In yet another arrangement, a miniaturized, flexible voltage up-converting instrument includes an X-ray generating source insertable into a body of a patient to a location in close proximity to a desired point of X-ray application. A first modular voltage up-converter is coupled to the X-ray generating source so that an up-converted voltage is applied to the X-ray source to generate a desired amount of X-ray dose at the desired point of X-ray application.
[0024] These as well as other advantages of various aspects of applicant's present arrangements will become apparent to those of ordinary skill in the art by reading the following detailed description, with appropriate reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] An exemplary arrangement described herein with reference to the drawings, in which:
[0026] [0026]FIG. 1 illustrates a known miniature X-ray apparatus system;
[0027] [0027]FIG. 2 is a cross sectional view of the high-voltage cable of a miniature X-ray apparatus system illustrated in FIG. 1;
[0028] [0028]FIG. 3 illustrates a schematic representation of a preferred arrangement of a miniature, flexible voltage up-converter system comprising a plurality of voltage up-converter modules;
[0029] [0029]FIG. 4 illustrates a schematic representation of one of the plurality of voltage up-converter modules provided in the up-converter system illustrated in FIG. 3;
[0030] [0030]FIG. 5 illustrates a flow chart providing certain processing steps for fabricating an arrangement of the voltage up-converter illustrated in FIG. 4;
[0031] [0031]FIG. 6( a ) illustrates a first processing step for fabricating a lateral type photodiode pattern that can be used for the voltage up-converter module illustrated in FIG. 4;
[0032] [0032]FIG. 6( b ) illustrates another processing step for fabricating the voltage upconverter illustrated in FIG. 4;
[0033] [0033]FIG. 6( c ) illustrates another processing step for fabricating the voltage upconverter illustrated in FIG. 4;
[0034] [0034]FIG. 6( d ) illustrates another processing step for fabricating the voltage upconverter illustrated in FIG. 4;
[0035] [0035]FIG. 6( e ) illustrates another processing step for fabricating the voltage up-converter illustrated in FIG. 4;
[0036] [0036]FIG. 6( f ) illustrates another processing step for fabricating the voltage up-converter illustrated in FIG. 4;
[0037] [0037]FIG. 6( g ) illustrates a cross sectional view of the voltage up-converter illustrated in FIG. 6( f );
[0038] [0038]FIG. 6( h ) illustrates another processing step for fabricating the voltage upconverter illustrated in FIG. 4;
[0039] [0039]FIG. 6( i ) illustrates a cross section of the FIG. 6( h ) including an additional processing step;
[0040] [0040]FIG. 7 illustrates a representative voltage (V) versus current (I) graph of one of the photo-diodes included in the voltage up-converter section illustrated in FIG. 6( a );
[0041] [0041]FIG. 8 illustrates a perspective view of the voltage up-converter module illustrated in FIG. 3 fabricated on a sapphire substrate;
[0042] [0042]FIG. 9 is a side view of a voltage up-converter illustrated in FIG. 8 coupled to a light source;
[0043] [0043]FIG. 10( a ) illustrates a preferred arrangement of an encapsulated voltage-upconverter module; and
[0044] [0044]FIG. 10( b ) illustrates another preferred arrangement of an encapsulated voltage-up-converter module.
DETAILED DESCRIPTION
[0045] 1. Overview
[0046] As previously described, X-ray generating devices require a large potential voltage. For example, a proposed X-ray device, such as the X-ray device illustrated in FIG. 1, generally requires an applied voltage on the order of between 15 kV to 30 kV. Providing such a large potential voltage presents certain safety concerns, especially where the X-ray generator is provided in a miniaturized instrument, such as a catheter. For example, one such typical X-ray device system is illustrated in FIG. 1.
[0047] [0047]FIG. 1 illustrates a schematic view of a proposed arrangement of a high voltage X-ray system 10 . The X-ray system 10 includes an instrumentation system 18 and an X-ray enclosure 14 . The enclosure 14 contains an X-ray emitting apparatus 12 . Apparatus 12 includes an X-ray emitting source and a high voltage wire 16 . The X-ray emitting source is located at a distal end of the enclosure. The X-ray emitting source 12 must be electrically coupled to the high voltage source 22 , such as by way of a high voltage wire 16 .
[0048] As seen from FIG. 1, the X-ray source 12 includes an X-ray emitting head 21 and a power wire 16 to which the head 21 is connected. The instrumentation system 18 is also provided and includes a control unit 20 and a high voltage power source 22 . The control unit 20 , preferably an operator controlled unit, operates the X-ray unit and determines, via an operator control device, when the X-ray apparatus begins irradiation. The operator control device (not shown) could be a foot switch or other human interface, such as a button, switch, or other like device.
[0049] As illustrated in FIG. 1, the X-ray apparatus is directly coupled to the high voltage wire 16 . The high voltage cable runs the length of the X-ray system housing 14 , L h . At one end d of the X-ray system housing 14 , the high voltage wire terminates at the instrumentation system 18 where the high voltage wire is electrically coupled to the high voltage power source 22 .
[0050] Typically, the X-ray head 21 will include a vacuum chamber. The vacuum chamber houses a microscopic cathode for generating electrons. An anode will also be provided. The anode accelerates and attracts the electrons and emits X-ray radiation 24 upon bombardment by the accelerated electrons. The emitted X-ray radiation is then used to irradiate a constricted artery, a cancerous growth (tumor), or other unwanted substance. For more information relating to such a typical X-ray head, the reader is directed to Tang U.S. Pat. No. 5,729,583; Parker U.S. Pat. No. 5,090,043; Smith U.S. Pat. No. 5,984,853; and Smith U.S. Pat. No. 6,241,651, herein entirely incorporated by reference and to which the reader is directed for further details.
[0051] As illustrated, the X-ray emitter 12 resides within an enclosure 14 . Such an enclosure could include a manually manipulated medical device used for in-vivo applications. For example, the housing illustrated in FIG. 1 could be a catheter used in an angioplasty operation. Alternatively, the miniaturized X-ray source could be used or placed within the confines of a structure that requires a high potential including dental applications, desk top crystallography, protein examinations, and the like.
[0052] One limitation as to the manipulation of the arrangement of FIG. 1 relates to the actual size of the X-ray unit 12 (L x ) and its diameter and the high voltage wire provided along the length L h of the body. Where the X-ray unit 12 has a length of L h , the catheter head 21 would not be able to be flexed along this portion of the enclosure. Rather, the housing could only be flexed in between the points of b and d and could not be flexed between the points of c and b. The actual size of the catheter head 21 therefore, restrains the manipulation of the enclosure.
[0053] Another limitation of the arrangement illustrated in FIG. 1 stems from the fact that the high voltage wire 16 carries the high voltage the entire distance L h from the power source to the X-ray unit 12 . Therefore, there is a potential risk that there will be a breakdown between the internal wire and the catheter outer enclosure 26 (i.e., ground). This is particularly problematic given that a potential breakdown could occur anywhere along the entire length of the catheter since a voltage of significant magnitude is present along the entire length of the cable. This is particularly problematic given that the enclosure may be used as an in-vivo medical instrument.
[0054] The X-ray apparatus 14 comprises both a distal end and a proximal end. Where the high voltage power source is utilized to generate X-rays, the high voltage power source will ordinarily be located in the proximal end of the medical device. Once the X-ray unit is energized with a desired amount of power, X-rays 24 are emitted from the distal end. Preferably, these X-rays 24 are emitted in a rotational symmetric fashion.
[0055] [0055]FIG. 2 illustrates a cross sectional view of the device housing illustrated in FIG. 1 along the A-A′ view. Referring now to FIGS. 1 and 2, typically, the enclosure housing 26 of the system 10 has a diameter d ranging from about 1.4 to about 2 millimeter (mm). Diameter d may be measured from the center of the high voltage wire 16 to the outer wall 28 of enclosure 26 . A proposed X-ray device, such as the X-ray device 12 illustrated in FIG. 1, may have a diameter of approximately 1-2 mm and may have a length Lx of approximately 2-4 mm long. The catheter extends from the proximal end to the distal end wherein this length L h could be as long as 3 feet. Supplying a high voltage (20 kV) along a 3 foot cable having a diameter of about 2 mm presents a dangerous situation since the energy stored along the catheter is large and therefore, the catheter in essence acts like a large, charged capacitor.
[0056] This may be seen by equating the energy stored in such a system. For example, the stored energy of the system may be calculated using the following equation: U=½C*V 2 , where U is the stored potential energy, C is the capacitance, and V the voltage. For a catheter having a diameter of approximately 1.4 mm and the high voltage wire having a radius r 1 ranging from 40 to approximately 220 micrometers (μm), the overall capacitance of the device will generally range from 3.9×10 −11 to 9.6×10 −11 Farads for a 3 foot cable and catheter system. If the X-ray source 12 required about 20 kV of power, the total energy stored along the device would approach 0.01 Watt-seconds. If this energy were to inadvertently discharge during a short time period, for example during 1 micro-second (μsec) time interval, the dissipated power (P=U/T) would be at a dangerous level: P=104 Watts. Therefore, by providing a point of use power supply (providing a desired amount of power at only one specific point), which is in close proximity to the X-ray head, the overall system capacitance may be significantly reduced and therefore the capacitive discharge potential.
[0057] [0057]FIG. 3 illustrates one preferred arrangement of a voltage up-converter system 50 . The system 50 includes a voltage up-converting point of use device 52 coupled to an instrumentation control 54 . The instrumentation control 54 includes a power source 56 , a light source 58 , and a control circuit 57 .
[0058] The up-converting point of use device 52 extends from a distal end 51 to a proximal end 53 and includes a plurality of voltage up-converter modules 62 ( a - d ). An X-ray emitter 64 is provided at the distal end. As illustrated in FIG. 3, the up-converting point of use device includes four up-converter modules are shown. However, it will be appreciated by those of ordinary skill in the art that other upconverter modules may also be utilized. For example, a point of use device could have more or less than four modules depending on the overall design and performance requirements sought.
[0059] As will be described in further detail below, each voltage up-converter module 62 ( a - d ) comprises a plurality of photodiodes. As can be seen from the arrangement illustrated in FIG. 3, the modules 62 ( a - d ) are coupled in a cascaded series, one after the other. Alternatively, a miniaturized up-converting module could comprise, rather than photodiodes, certain conventional, relatively compact voltage sources. For example, a voltage source such as the voltage sources disclosed in U.S. Pat. Nos. 5,282,122 and 4,241,360, herein entirely incorporated by reference and to which the reader is directed for further details, may be used in certain circumstances where a miniaturized, flexible, device is desired.
[0060] Each up-converter module provides an incremental voltage up-conversion from an initial input voltage. Such an initial input voltage may be provided from the power source 56 or as an up-converted voltage from another up-converter module. A final up-converted voltage is then available at the X-ray emitter 64 . For example, the first voltage up-converter module 62 ( a ) receives a first input voltage and up-converts this first input voltage to a first output voltage. This first input voltage may be received by the power source 56 of the instrumentation control 54 . Alternatively, because of the current and voltage characteristics of the solid state components making up the up-converter module 62 ( a ), an initial input voltage may not be required. In such a scenario, a photon source 72 is provided by the light source 58 along the fiber optic cable 70 . In this manner, the photons provided by the first fiber optic cable 72 are used to optically generate an output voltage so as to provide an input to the second up-converting module 62 b.
[0061] The first output voltage (and now a second input voltage) is then applied to the second voltage up-converter module 62 ( b ). This second up-converter module 62 ( b ) up-converts this input voltage to a second output voltage (i.e., a third input voltage). Voltage up-converter 62 ( b ) then provides an up-converted output voltage to a third voltage up-converter module 62 ( c ). As with the first and the second voltage up-converters 62 ( a - b ), the third voltage up-converter module 62 ( c ) up-converters this input voltage and provides an output voltage to the fourth and final power supply module 62 ( d ). In this up-converting manner, the modules may be fabricated so as to produce a known and desired, final up-converted voltage to the X-ray device 64 . This up-converted voltage is then used by the X-ray device 64 to generate the X-rays 66 .
[0062] An anode of the X-ray emitter receives this voltage from the fourth voltage upconverter and, under the control of the operator control system 57 , emits an X-ray pattern 66 as previously described above.
[0063] Preferably, both the X-ray source 64 and the up-converting modules are contained within a single enclosure, such as a medical instrument (a catheter). In the arrangement illustrated in FIG. 3, four up-converting modules are provided. However, as those of ordinary skill will recognize, other up-converting module arrangements may also be provided. Those of ordinary skill will also recognize, as will be described, various aspects of up-converting module fabrication will tend to effect a number of modules required to eventually produce the necessary and desired final voltage to be provided to the X-ray device 64 . Varying an initial input voltage will also affect the final up-converted output voltage.
[0064] The up-converting device may be designed to produce a wide array of different voltages. For example, in one arrangement, the first modular section 62 ( a ) has an input potential supplied along input line 71 of approximately 0 to 1000 volts and up-converts this input voltage to approximately 4 kV. This initial input potential could be provided by the power source 56 . Other input potentials could also be provided. For example, in one arrangement, the input potential may be 0 volts. In such an arrangement, the first modular section relies on a light source (photon source via fiber optic cable) to provide an initial voltage up-conversion.
[0065] In one arrangement, the voltage up-converter modules 62 ( a - d ) are all essentially identical modules. That is, each up-converter module has been fabricated so as to produce essentially the same up-converting characteristics (each module up-converts an input voltage by the same amount: 4-5 kV). Alternative arrangements may also be provided wherein the modules comprise different up-converting characteristics (up-converting rates) to thereby produce different up-converting voltages. For example, a first up-converting module could up-convert an input of 0.1 kV to 3 kV (an up-converting rate of approximately 3 kV) and a second upconverting module could up-convert 3 kV to 9 kV (an up-converting rate of approximately 6 kV). As those of ordinary skill in the art will recognize, other upconverting rates may also be provided.
[0066] Returning to FIG. 3, the second modular section 62 b receives the output of the up-converting module 62 ( a ) along voltage line 75 and up-converts this input voltage (4-5 kV) to a second voltage that may be provided at voltage line 77 . In one arrangement, this second voltage is 10 kV. This up-converting process is repeated through the remaining modular sections. In this manner, the fourth modular section 62 ( d ) up-converts an input voltage provided along voltage line 79 to an output voltage of 20 kV. For certain angioplasty operations, this is a sufficient voltage.
[0067] One advantage of the device illustrated in FIG. 3 is that there is generally only one general location in the entire system where a peak voltage of 20 kV is provided. This point is located at the output of the fourth up-converter modular section 62 ( d ). It is only at the fourth modular section output (at the X-ray unit 64 ), therefore, that the greatest probability of a dielectric breakdown can occur. However, unlike in certain proposed miniaturized high voltage configurations, this peak voltage is not present, nor is it required, along the entire length of the voltage source enclosure. Rather, any peak voltage is provided at only one point: the input of the X-ray unit. Consequently, the overall structural charge-up capacitance of the entire structure is reduced and may be reduced to approximately the size of the last modular section (i.e., the size of modular section 62 ( d )).
[0068] In one arrangement, the size of the last modular section, and therefore the relevant capacitance, is roughly on the order of about 1 millimeter. In one arrangement, the overall capacitance may be reduced by a factor of 1000 over the proposed system illustrated in FIG. 1 by reducing the length from 3 feet (˜1000 mm) to 1 mm, which is the X-ray head. Therefore, in the advent of an inadvertent discharge, only 10 Watts would be discharged as compared to 10,000 Watts as mentioned above.
[0069] The voltage up-converter arrangement illustrated in FIG. 3 provides a number of advantages. One advantage is that peak voltages are only present at the desired point of X-ray application. That is, the peak voltage is available only near at the X-ray unit. Therefore, the peak voltage need not propagate along the entire length of the catheter. Therefore, the point of highest voltage has the largest probability of dielectric breakdown. Here, because the size of the last modular section is miniaturized, the system's overall capacitance is also quite small since the length of the capacitance (i.e., the length of the last modular component) is only on the order of 1 mm. Consequently, the overall system concern for flashback is substantially reduced.
[0070] Another advantage of the arrangement illustrated in FIG. 3 is its flexible characteristics. As previously discussed, there is a need for a flexible and maneuverable device that allows an up-converted voltage to be applied at certain small locations. Because of the multi-sectioned structure of the arrangement illustrated in FIG. 3, the device 50 can be manipulated in various configurations.
[0071] Several methods may be implemented to fabricate one of the modular sections provided in the system illustrated in FIG. 3. For example, FIG. 4 illustrates an arrangement 90 of one of the up-converting modular sections illustrated in FIG. 3. In this arrangement, the modular section comprises a solid-state device containing a large number (several thousand) laterally fabricated photodiodes. A schematic representation of such a potential photo diode arrangement 90 is illustrated in FIG. 4. In this schematic representation, the photo diode arrangement 90 has a width of W and a length of L. In one arrangement, this width W is about 1.0 mm and this length L is about 1.3 mm. Such dimensions make this photo diode module an ideal candidate for applications requiring a miniaturized “point of use” power source.
[0072] As shown in FIG. 4, the arrangement 90 includes a serial array of diodes provided along a substrate surface. Preferably, this substrate comprises a sapphire supporting structure. The photodiodes making up the modular section 90 are fabricated in a cascaded, serial fashion. Preferably, and as will be discussed in greater detail below, the photodiodes are laterally disposed in a pattern along a substrate surface and configured in a generally meandering type of configuration as shown in FIG. 4. The photodiodes begin at a first termination point 93 , wind along the meandering photodiode pattern, and eventually end at a second termination point 95 . The modular section 90 is provided with an input voltage at a modular section voltage input line 92 , up-converts this input voltage, and then provides a modular section voltage output at line 94 . The modular section input, normally a wire, can receive an initial potential voltage (e.g., 0-1000 volts). Line 94 provides an output voltage. Where the input wire supplies an input voltage, the modular section up-converts the initial potential voltage to a second potential voltage which can then be supplied as an input to another modular section. Alternatively, where the modular structure 90 is the last modular section in a cascaded plurality of sections (such as the forth modular section 62 ( d ) illustrated in FIG. 3), section 90 provides an up-converted peak voltage to a device, such as the X-ray unit 64 illustrated in FIG. 3. The modular section 90 is optically coupled to a light source via an optical fiber 96 . Fiber 96 provides a source of light (photons) so as to energize the plurality of photo diodes 100 . For example, in one arrangement, the modular section 90 receives a source of photons 98 over optical fiber 96 , wherein, the optical fiber 96 is optically coupled to a light source, such as the light source 58 illustrated in FIG. 3. In one arrangement, the optical fiber 96 has a diameter of 120 um (0.12 mm). In one arrangement, the fiber optic cable 96 is bundled with a plurality of other optical fibers. These various optical fibers act as a separate photon source to each modular section.
[0073] The modular section can be fabricated to have a length designated L and a width designated W such that the modular section is small enough to be contained in a miniature instrument, such as the instrument illustrated in FIG. 3. More preferably, in one arrangement, the designated length L is 1.3 mm and the designated width W is 1 mm. However, as those of ordinary skill in the art will recognize, other structures, configurations, and/or dimensions may also be utilized.
[0074] The modular structure 90 may be encapsulated within an encapsulation media 98 . Encapsulation media 98 is shown in FIG. 4 as surrounding or “encapsulating” the modular device substrate. Wires 92 , 94 and the fiber optic cable 96 protrude outside the encapsulated area. In such an arrangement, the encapsulation media 98 provides a degree of optical and electrical isolation between the optical sensitivities of the plurality of photodiodes 100 and an environment surrounding the encapsulated media. The media could comprise certain plastics, pyrelene, Teflon, polyimide, certain forms of polydimethylsiloxane (PDMS), or other types. The encapsulation medium 98 also provides a degree of stability (or support) for the wire 92 , the outgoing wire 94 , and the fiber optic cable 96 .
[0075] Utilizing the arrangement illustrated in FIG. 4, a large number of photo-diodes may be fabricated onto a small substrate footprint. Generally, the greater the number of photodiodes per module, the greater the module's up-converting rate. This can be illustrated by equating the number of diodes that may be fabricated onto a 1×1.3 mm 2 chip, such as the modular section illustrated in FIG. 4. The unit cell (area per diode) is 15×10 μm so this equals 150 μm. The total area of the up-converter module is 1×1.3 mm=1000×1300=1.3×10 6 μm 2 . If N is defined as the number of diodes per module, one can see that N=(1.3×10 6 )/150 which equals approximately 8,700 diodes. Therefore, if each photodiode generates a photo voltage of approximately 0.5 volts, a module comprising 8,700 photo-diodes can generate 4350 volts (4.35 kV). Modular sections having other up-converting rates may also be fabricated in a similar manner. In addition to silicon as described below, other photo materials may also be used, including Gallium Arsenide.
[0076] The photodiodes provided in the modular section 90 may be fabricated utilizing various methods. One such method involves the fabricating process 112 illustrated in FIG. 5. Process 112 is particularly useful in fabricating an array of laterally disposed photo-diodes. Process 112 will be described in reference to FIG. 5 and the various steps illustrated in FIGS. 6 ( a - i ).
[0077] First, at step 114 and as illustrated in FIG. 6( a ), a silicon-on-insulator substrate 142 may be quartz (SiO 2 ) or alternatively, sapphire (Al 2 O 3 ), is first provided. This substrate contains commercially available polycrystalline silicon, laser crystallized polycrystalline silicon, or single crystal silicon. This is referred to as Silicon-On-Insulator (S-O-I).
[0078] Ion implantation (phosphorus or arsenic) is performed to render the undoped silicon of the SOI wafer slightly n − type at a desired concentration, preferably at a concentration of approximately 1×10 15 atoms/cm 3 to 8×10 15 atoms/cm 3 .
[0079] Next, referring now to FIG. 6( a ), a photo-diode pattern 144 is formed by depositing a positive photoresist on substrate 142 . This photo-diode patterning occurs at step 118 in FIG. 5.
[0080] Next, a photoresist is provided. Such a positive photoresist may be Shipley 1818 that is deposited onto the substrate 142 by spin coating. Other coating methods could also be used. After baking at about 100° C. for several minutes, the photoresist is then exposed via a mask using an ultraviolet light source. The photodiode pattern 144 is developed and the silicon is etched using a plasma etcher containing a CF 4 /O 2 mixture. Other etching gases can be used as well as chemical etchants.
[0081] The pattern 144 is preferably of a meander-type pattern. As will be explained in further detail below, such a meandering photo-diode type pattern results in an array structure that provides a high density of serially connected laterally constructed diodes (photo-diodes/mm 2 ). Those of skill in the art, however, will note that other type of photo-diode pattern could also be used. For example, certain patterns could be chosen that maximize the distance between the input voltage and the up-converted voltage.
[0082] As can be seen from FIG. 6( a ), the meander-type pattern 144 comprises a number of columns 145 ( a - e ) and a number of rows 141 ( a - e ). These various columns 145 ( a - e ) are attached via a number of rows 141 ( a - e ). For example, column 145 ( c ) is connected to column 145 ( d ) via row 141 ( c ). In one arrangement, each column has a width w 1 of approximately 5 μm and each row connecting adjacent columns has a width w 2 of approximately 5 μm.
[0083] The meandering type pattern 144 begins at a first terminal point 156 and extends across a surface 142 of the substrate 140 to a second terminal point 157 . The first terminal point 156 has a larger width than the rows and will preferably provide a contact point for an electrical connection, such as for the wire 92 illustrated in FIG. 4. Similarly, the second terminal point 157 has a width large enough so as to provide a contact point for another electrical connection, such as for the wire 94 illustrated in FIG. 4.
[0084] As a next step in the fabrication process, a p + type implant takes place. (step 120 , FIG. 5). FIG. 6( b ) illustrates p + type implantation along a portion of the photo-diode pattern 144 illustrated in FIG. 6( a ). Prior to this procedure, the photoresist on top of the n − silicon 144 of FIG. 6( a ) has been removed via a wet or a dry stripping step.
[0085] A photo-resist step is now repeated to fabricate a multitude of p + regions along the meandering pattern 144 . Boron could be used to fabricate these p + regions. A photo resist is then spun on, baked, exposed, and developed and boron is ion implanted to a concentration of about 1×10 18 ions/cm 3 to about 5×10 8 ions/cm 3 in the regions where the photoresist has been developed (see FIG. 6 b ).
[0086] [0086]FIG. 6( b ) illustrates a fabricated region portion 150 of the n − implanted meander 144 . As illustrated in FIG. 6( b ), the fabricated portion 150 comprises a first p + implant zone 156 and a second p + implant zone 158 . Adjacent this first p + implant region 156 is a first photoresist 154 protecting an underlying n − implanted region during p + implant. The second p + implant region 158 is provided adjacent the first and the second photo resists 154 , 152 , respectively. The remainder of the entire photo-diode pattern 144 of FIG. 6( a ) extending from the first termination point 156 to the second termination point 157 is fabricated in a similar manner.
[0087] Prior to the next implantation step, the photoresist regions are removed. (step 122 in FIG. 5) and an n + implantation process occurs at step 126 of FIG. 5. This n + implantation step 126 is illustrated in FIG. 6( c ). As shown, fabricated substrate portion 160 includes a first, a second, and a third photoresist area 162 , 164 , and 166 , respectively. These photoresist areas act to protect the underlying previously implanted regions. The n + implants are represented by areas 170 and 168 . In one arrangement, the n + implant comprises either phosphorous or arsenic and is implanted to a concentration of approximately 1×10 18 to 5×10 18 ions/cm 3 .
[0088] In a next step, the photoresist regions 162 , 164 , and 166 are removed. Removing the photoresists 162 , 164 , and 166 results in a top view of a portion of a fabricated device 180 is illustrated in FIG. 6( d ). As shown in FIG. 6( d ), the fabricated device 180 now comprises a p + region defining a first termination point 182 . Adjacent this p + region termination point 182 is an n − type region 183 A, an n + type region 183 B, and then another p + type region 183 C. This p + to n − to n + pattern is repeated throughout the photodiode pattern, extending from the first termination point 156 to the second termination point 157 of FIG. 6( a ).
[0089] At step 128 (FIG. 5), the silicon and substrate are cleaned. After the cleaning step 128 , a protective oxide layer, preferably SiO 2 , is grown over the various doped silicon regions. This occurs at step 130 . In one arrangement, an oxide layer of about 1000 Angstroms is grown at about 950-1000 degrees Celsius. During the oxide layer growing process, the ion implanted regions are being activated, i.e., the ion implanted regions are rendered electrically conductive.
[0090] [0090]FIG. 6( e ) illustrates a cut away view along view B-B′ of the substrate portion 180 illustrated in FIG. 6( d ). This cut-away view illustrates the substrate 194 after an oxide layer 192 has been grown over the surface 193 of the device 190 . As shown, the lateral array of the various doped regions comprising the photodiodes 197 are disposed along the top surface 193 of the substrate layer 194 .
[0091] A next process step includes photo-masking the substrate to form a contact opening. Preferably, at least two contact openings per photodiode module are formed. For example, as illustrated in FIG. 6( f ), a photo-resist 202 is provided over a portion of the substrate, excluding the developed areas over region 182 of FIG. 6 d and partial regions where p + and n + regions meet. The SiO 2 layer, in the unprotected regions, is etched using buffered HF (hydrofluoric acid). After photoresist stripping, the device looks like what is illustrated in FIG. 6 g . The SiO 2 is removed from surface portions 211 , 213 overlaying the laterally disposed p + region 211 and from a region overlapping adjacent n + and p + regions 213 .
[0092] In the next process step 131 (FIG. 5), contact material is deposited along the surface of the fabricated substrate. This deposited contact material is photo-shaped to form a contact region for the voltage input and output. This deposited contact material is also photo-shaped to shunt the p + and the n + regions. Preferably, the contact material is aluminum, however, Cr/Au or other similar materials. Good contacts can be formed to the silicon regions and wire bonds may be formed on the contact material. FIG. 6( h ) shows a top view of the photodiode device with two metal regions 242 , 244 as described above. Wire 264 may then be connected to contact material in FIG. 6( i ) by wire bonding, such as to apply an input voltage for up-converting.
[0093] [0093]FIG. 6( i ) illustrates the cross section of the device shown in FIG. 6( h ) with the inclusion of the wire to 264 to contact material 256 .
[0094] As a next processing step, the device illustrated in FIG. 6( i ) may be encapsulated in an encapsulation media. Encapsulation provides a number of advantageous features. For example, encapsulation protects against moisture, provides the fabricated up-converting module with an enhanced level of rigidity, and also prepares for inclusion into a medical device.
[0095] The process illustrated in FIGS. 5 and 6( a - i ) results in a plurality of photodiodes laterally fabricated along a substrate surface. FIG. 7 illustrates a current versus voltage graph 270 that demonstrates how the fabricated photo-diode device utilizes an optical source to provide voltage up-converting. As shown in the graph 270 , the line V dark 278 represents the ordinary operating characteristic of a photodiode absent any illumination. In this condition, the voltage versus current characteristics demonstrate that there is no voltage output at zero current.
[0096] However, once the photodiode is illuminated, the current versus voltage graph shifts. This shift is graphically represented as V light , 277 . V light 277 has now shifted along the y-axis so that now, the graph intercept with the x-axis has shifted where this shift is defined as V OC or the photodiode's photo-voltage when no current is drawn (an open circuit condition). Ordinarily, such a diode photo-voltage may be on the order of approximately 0.5 volts. When current is drawn, the open circuit voltage is somewhat lowered.
[0097] [0097]FIG. 8 illustrates a perspective view of a fabricated miniaturized up-converter module 300 prior to encapsulation. The miniaturized up-converter device 300 comprises the doped regions arranged in a meandering pattern 309 and provided along a substrate surface 302 . A first wire 306 provides an input voltage V 1 at a first termination point. A second wire 304 is used to supply a remote device with an up-converted output voltage V 2 at the second termination point. This upconverted output voltage V 2 may then be supplied to another miniaturized upconverter module, like device 300 , or may be used to provide an up-converted voltage to a device such as an X-ray device.
[0098] [0098]FIG. 9 illustrates a photodiode module 320 connected to a fiber. The encapsulated module 320 provides a photodiode device 346 encapsulated within a structure 348 . The photodiode device 346 is encapsulated within a structure 348 . The photodiode device 346 includes an input wire 322 and an output wire 324 , both wires extend beyond the encapsulation structure 348 . At one end of the enclosure, a fiber optic light source 326 is provided for providing a source of photons 328 . These photons are incident along the plurality of photodiodes residing along a bottom surface 344 of the up-converting module 346 . As the photons propagate along the length of the module 346 , from the fiber optic cable 326 to a back end 342 . Some of the photons reflect off the module bottom surface 344 and off of a bottom enclosure portion 341 . The fiber optic cable 326 is fixedly attached to the module via glue 342 or some other adhesive.
[0099] A reflective surface 340 may be provided along the top surface of this portion so as to increase an overall reflectivity along the bottom portion 341 . A structure back end 342 may also be provided with a reflecting medium 343 . The reflective medium may be chosen to have an index of reflection so as to enable the photons reflecting off of this back surface to be totally internally reflected.
[0100] In one arrangement, the up-converting module, such as the module illustrated in FIG. 9, may be encapsulated. For example, two types of module encapsulation arrangements are illustrated FIGS. 10 a and b . FIG. 10 a illustrates one encapsulation arrangement wherein each separate module is independently encapsulated. In FIG. 10 a , a first encapsulated module 361 is provided with an input wire 364 and an output wire 366 . The output wire 366 is electrically coupled to an input wire of a second encapsulated module 363 . The second encapsulated model 363 also includes an output wire 362 that may be electrically coupled to another encapsulated module. Alternatively, output wire 362 may be electrically coupled to a device requiring a peak up-converted voltage, such as an X-ray device.
[0101] [0101]FIG. 10 b illustrates an alternative encapsulation arrangement. FIG. 10 b illustrates an encapsulation arrangement wherein two up-converting modules are encapsulated within a single encapsulation structure 378 . In FIG. 10 b , a first module 371 has an input wire 372 and an output wire 376 . The output wire 376 is coupled to an input wire of a second module 373 . The second model 373 includes an output wire 374 that may be coupled to another encapsulated module or other device requiring an up-converted voltage, such as an X-ray device.
[0102] Exemplary embodiments of the present invention have been described. Those skilled in the art will understand, however, that changes and modifications may be made to these embodiments without departing from the true scope and spirit of the present invention, which is defined by the claims.
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A method and apparatus for providing a miniaturized, flexible high voltage upconverter. Aspects of the invention are particularly useful in providing an apparatus comprising a plurality of up-converting modules while also allowing the apparatus to maintain a desired degree of flexibility. However, certain aspects of the invention may be equally applicable in other scenarios as well.
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FIELD OF THE INVENTION
[0001] This invention relates generally to a method and system for evaluating a mixture containing colored objects, and more particularly, for evaluating the purity of cullet.
INCORPORATION BY REFERENCE
[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
BACKGROUND
[0003] Glass containers are 100% recyclable and can be recycled endlessly without any loss in purity or quality. Over a ton of natural resources are saved for every ton of glass recycled. Energy costs drop about 2-3% for every 10% cullet (post-consumer glass) used in the manufacturing process. Glass furnace life is increased by 10% when recycled glass is used in the production of new glass containers. One ton of carbon dioxide is reduced for every six tons of recycled container glass used in the manufacturing process.
[0004] Although glass container manufacturers are able to use as much as 95% recycled glass in the manufacturing process, glass container manufacturers often use only about 35% recycled glass. When using recycled glass as feedstock to manufacture new glass containers, energy costs of glass container manufacturers can be 15% less, emissions can be reduced by 20%, and furnace life can be extended by 10%. Glass container manufacturers prefer to use all the recycled furnace-ready cullet they can procure. A significant barrier to this is the quality of recycled glass available and assurance that the cullet receive is furnace-ready cullet, which must be high purity clean and color-sorted. With contaminated cullet, the reject rate in the manufacture of new glass containers increases, which increases the cost of manufacturing new glass containers. Even one small contaminant in a manufactured bottle can result in rejection.
[0005] Consumers place their recyclables by their curb side, which is picked up by hauling companies and taken to a Material Recovery Facility (MRF) where the various recyclables are sorted out and the residual, which is a mixture having high glass content, is sent to Glass Processors to be cleaned, color sorted and then sold as cullet to glass container manufacturers for use in producing new glass containers.
[0006] In years past, consumers had to place recyclables in different bins by their curb side. However, in order to reduce the cost of recycling and increase the amount that is recycled, cities have since transitioned to “single stream collection” whereby all recyclables are placed in a single bin. With single stream collection, Material Recovery Facilities (MRFs) have to deal with co-mingled material. While MRFs remove larger pieces of paper, most of aluminum cans and plastic containers, their residue and what they are unable to remove, comes out of their facilities with a large percentage of broken glass, typically as three-color (clear, brown, green) mixed dirty glass. So glass is part of this residual that MRFs send to glass processors, hence the glass is mixed with a lot of other material which is considered to be contaminants. The glass processors receive this as their raw material feedstock, which can contain as much as 40 to 50% contaminant (non-glass). However, the furnace-ready cullet which glass processors are required to provide to glass container manufacturers must contain less than 0.001% contaminant or almost 100% clean color sorted glass. The quality of cullet is the most important factor for glass container manufacturers.
[0007] While producing quality cullet is important, the ability to test the cullet is crucial. Today glass processors use manual methods to test the quality of the cullet that is delivered to them. A material sample, usually 50 lbs, is spread on a work table, a quality inspection person manually separates the contents of the sample, weighs each content group, fills out a sheet of paper with data which is compared to the specification of the glass container manufacturer (or other end user) to determine if the cullet delivery passes or fails to meet specifications. This manual process can take up to 45 minutes for each sample. The samples have to be tested several times a day and for each truck shipment, adding high labor cost to the end product. Accordingly, there is a need for efficient and accurate method and system for testing the quality of cullet.
SUMMARY
[0008] Described herein are a method and system for glass processing.
[0009] Various aspects of the invention are directed to a method comprises taking an image of an object from the mixture, the object possibly being either a single piece from the mixture or at least two pieces from the mixture. The method further comprises determining, from the image, angles of an outline of the object. The method further comprises evaluating the angles to determine whether the object is at least two pieces, and evaluating a characteristic of the object.
[0010] Various aspects of the invention are directed to a system comprises an imaging device configured to take an image of an object from the mixture, the object possibly being either a single piece from the mixture or at least two pieces from the mixture. The system further comprises a light source configured to direct light toward the imaging device. The system further comprises a processor configured to determining, from an image taken by the imaging device, angles of an outline of the object. The processor is further configured to evaluate the angles to determine whether the object is at least two pieces and to evaluate a characteristic of the object.
[0011] Various aspects of the invention are directed to a non-transitory computer readable medium having a stored computer program embodying instructions, which when executed by a computer, causes the computer to evaluate a mixture including a plurality glass pieces. The computer readable medium comprises instructions to take an image of an object from the mixture, the object possibly being either a single piece from the mixture or at least two pieces from the mixture. The computer readable medium further comprises instructions to determine, from the image, angles of an outline of the object instructions to evaluate the angles to determine whether the object is at least two pieces, and instructions to evaluate a characteristic of the object.
[0012] Various aspects of the invention are directed to a method comprising taking an image of an object from the mixture, the object having the potential of being either a piece of glass with label or a piece of glass without a label. The method further comprises determining, from the image, angles of an outline of the object. The method further comprises detecting, from the image, a light transmittance boundary line within the outline of the object, the light transmittance boundary line having an endpoint on the outline. The method further comprises identifying the object as a piece of glass with a label based, at least, on the angle of the outline at the endpoint of the light transmittance boundary.
[0013] The features and advantages of the invention will be more readily understood from the following detailed description which should be read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic view of an exemplary system, showing an imaging device, processor coupled to the imaging device, a light source, and a plurality of objects to be examined.
[0015] FIG. 2 is a simulated image of the objects taken by the imaging device and communicated to the processor.
[0016] FIG. 3 is a block diagram showing an exemplary method.
[0017] FIG. 4 is a diagram showing object outlines obtained from the image of FIG. 2 .
[0018] FIG. 5 is a detailed view of the object outline of one of the objects in FIG. 4 .
[0019] FIG. 6 is a schematic view of an exemplary system, showing a glass sorter and quality test modules.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] Referring now in more detail to the exemplary drawings for purposes of illustrating embodiments of the invention, wherein like reference numerals designate corresponding or like elements among the several views, there is shown in FIG. 1 a plurality of objects 10 A- 10 D disposed between imaging device 12 and light source 14 . Imaging device 12 is configured to take an image of all objects 10 A- 10 D simultaneously, or optionally take an image of only one or a limited number of the objects.
[0021] Objects 10 A- 10 D are samples obtained from a mixture that includes many pieces of glass and non-glass debris material. The mixture can be residual material from a Material Recovery Facility (MRF). The mixture can be cullet produced by a glass processor which sorts residual material from the MRF. The mixture can be cullet received by a glass manufacturer for making new glass containers.
[0022] The glass pieces in the mixture can belong to various color types. Color types include without limitation clear (or flint), amber (or brown), and green. The non-glass debris material can be ceramic plastic, metal, wood, stone, or rock. The mixture can be a cullet mixture resulting from a prior process which attempted to separate glass pieces by color type. Additionally or alternatively, the mixture can be the result of a prior sorting process which attempted to remove non-glass debris material. The method and system described herein can be used to verify quality of the sorting process. For example, method and system can test whether a cullet mixture satisfies a predetermined requirement, such as 95% amber glass by weight and/or less than 5% non-glass debris material by weight. As another example, the predetermined requirement can be 98% clear glass by weight and/or less than 2% non-glass debris material by weight. Additionally or as an alternative to use after a sorting process, the method and system described herein can be used during the sorting process to help ensure that the resulting cullet mixture satisfies predetermined requirements.
[0023] In FIG. 1 , four objects ( 10 A- 10 D) are simultaneously within field of view 13 of imaging device 12 . It is possible for there to be a greater or lesser number of objects within field of view 13 than what is illustrated. As discussed below, any one of the four objects ( 10 A- 10 D) can in fact be multiple items. A system and method will be described for determining whether or not any of the objects ( 10 A- 10 D) comprises multiple items.
[0024] Light source 14 is configured to direct light toward objects 10 A- 10 D. The type of light includes visible light. Light source 14 is oriented such that an outline each of the objects can be detected by the imaging device 12 . Light source 14 includes any one or a combination of a mirror, a light guide, and a light generator such as a light bulb or light emitting diode (LED). The light directed by light source 14 allows imaging device 12 to determine the composition and characteristics of objects 10 A- 10 D. Characteristics includes without limitation color type and material type. Color type includes without limitation clear (or flint), amber (or brown), and green. Material type includes without limitation glass versus non-glass debris material.
[0025] Imaging device 12 can include one or more electronic sensors configured to detect the intensity and color of light passing through objects 10 A- 10 D and at the edges of objects 10 A- 10 D. Electronic sensors include without limitation charge-coupled devices (CCD) and complementary metal-oxide-semiconductors (CMOS). Imaging device 12 is coupled to processor 16 . Processor 16 includes one or more integrated circuits for evaluating images from the imaging device 12 and one or more memory components for storing the images.
[0026] FIG. 2 shows image 18 taken by imaging device 12 . Image 18 is stored and evaluated by processor 16 . Each of the objects 10 A- 10 D can actually be one or more pieces of glass and/or non-glass debris material. In the illustration, object 10 A consists of three overlapping pieces of glass, object 10 B consists of a single piece of glass, object 10 C consists of one piece of glass and one piece of non-glass debris material, and object 10 D consists of a single piece of glass with a label. The illustrated composition for the objects is exemplary and is not intended to limit the invention. Other combinations for each object are possible, such as: two pieces of glass with labels; two pieces of glass with labels and one piece of non-glass debris material; one piece of glass with a label, two pieces of glass without a label, and a piece of non-glass debris material; and so on.
[0027] Processor 16 is configured to determine the composition of each one of the objects ( 10 A- 10 D) by analyzing image 18 . The composition refers to the number of items present or contained in each object. By determining the composition of each object, it is possible to characterize the object more accurately and thereby enable a more accurate quality test of whether a cullet mixture meets predetermined requirements or enable more accurate sorting to ensure that the resulting cullet mixture meets the predetermined requirements. Without a determination of composition, object 10 A could be mistakenly characterized as a single piece of amber glass when in fact it consists of one piece of amber glass, one piece of clear glass, and one piece of green glass. As a further example, object 10 C could be mistakenly characterized as single of piece of desired glass when in fact it consists of one piece of desired glass and one piece of undesirable debris material. In yet another example, object 10 D could be mistakenly characterized as a single piece of undesirable debris material when it is a piece of desired glass with a label adhered to it. These potential inaccuracies can be avoided by analyzing image 18 to determine the composition of one or more of the objects.
[0028] In some embodiments, as shown in FIG. 3 , the determination of composition (block 20 ) of the objects ( 10 A- 10 D) includes determining, from image 18 , angles of an outline of the object (block 22 ). Next, angles are evaluated (block 24 ) to determine whether each of the objects contains at least two pieces.
[0029] Referring to FIG. 4 , the determination of angles (block 22 ) is performed by obtaining an outline of each of the objects ( 10 A- 10 D). The outline refers to edges of the object which define an area of image 18 occupied by the object. In FIG. 4 , only outlines 26 A- 26 D of the objects are illustrated. Other details of image 18 in FIG. 2 (such as indicators of color type, opacity, and where pieces overlap) are omitted from FIG. 4 to clarify the discussion below. Each of the outlines 26 A- 26 D includes one or more vertices. As discussed below, angles at each of the vertices can be used to determine the number of pieces in each object.
[0030] FIG. 5 shows a detailed view of outline 26 A of object 10 A. Outline 26 A includes vertices V 1 to V 13 . The interior angle Φ at each of the vertices is compared to a threshold value. For example, the threshold value can be 180 degrees, and processor 16 determines whether a vertex has an interior angle Φ greater than 180 degrees. Results of the comparison are shown in TABLE I.
[0000]
TABLE I
Does interior angle Φ
Vertex
violate threshold?
V1
No
V2
No
V3
YES (suspect vertex)
V4
No
V5
YES (suspect vertex)
V6
No
V7
No
V8
No
V9
No
V10
YES (suspect vertex)
V11
No
V12
YES (suspect vertex)
V13
No
[0031] The interior angle Φ of outline 26 A is greater than the threshold value of 180 degrees at vertices V 3 , V 5 , V 9 , and V 12 . A vertex which violates the threshold (e.g., has an interior angle Φ greater than 180 degrees) represents either a stress concentration that could result in the piece of glass breaking apart into more pieces or an intersection between two pieces of glass. For convenience of discussion, a vertex which violates the threshold is referred to as a suspect vertex. The threshold value is selected such that a suspect vertex is more likely to represent an intersection between two separate pieces. The threshold value of 180 degrees is selected to provide confidence that a suspect vertex most probably represents an intersection between two separate pieces, as opposed to representing a single piece of glass with a stress concentration. Other threshold values for the interior angle Φ can be selected, such as 185 degrees, 190 degrees, 195 degrees, 200 degrees, 205 degrees, and so on. The threshold value can be a value in the range of 180 degrees to 205 degrees, for example. In general, a greater threshold value can provide greater confidence that a suspect vertex truly represents an intersection between two separate pieces.
[0032] In some embodiments, the angle which is determined in block 22 of FIG. 3 is the exterior angle θ. For the exterior angle θ, the threshold angle is used in reverse. That is, a vertex is identified as a suspect vertex when its exterior angle θ is less than the threshold of 180 degrees. Other threshold values for the exterior angle θ can be selected, such as 185 degrees, 190 degrees, 195 degrees, 200 degrees, 205 degrees, and so on.
[0033] In some embodiments, a suspect vertex is paired with another suspect vertex as a condition to concluding that the two suspect vertices represent an intersection between two separate pieces. In FIG. 5 , processor 16 determines that leg L 5 of vertex V 5 is aligned with leg L 10 of vertex V 10 . Due to alignment of legs, processor 16 identifies vertices V 5 and V 10 as a suspect vertex pair and as an intersection between two separate pieces 28 and 30 . Alignment is found when legs L 5 and L 10 are on the same imaginary line (i.e., legs L 5 and L 10 are collinear) or when legs L 5 and L 10 form an angle that is less than an alignment threshold angle. The alignment threshold angle can be, for example, any one of 2 degrees, 4 degrees, 6 degrees, 8 degrees, 10 degrees, and so on.
[0034] Additionally or alternatively, processor 16 determines vertices V 5 and V 10 are in sufficient proximity to each other as a condition to concluding that the two suspect vertices represent an intersection between two separate pieces. Due to sufficient proximity, processor identifies vertices V 5 and V 10 as a suspect vertex pair and as an intersection between two separate pieces 28 and 30 . Sufficient proximity is found when the distance D between vertices V 5 and V 10 is within a threshold distance. The threshold for distance D can be an absolute distance. The absolute distance can be, for example, any one of 5 mm, 1 cm, 2 cm, 3 cm, 4 cm, and so on. The threshold for distance D can be a percentage of another dimension taken from outline 26 A. For example, the threshold for distance D can be a percentage (such as 50%, 100%, 150%, or 200%) of a leg (such as L 5 or L 10 ) adjacent to a suspect vertex. As a further example, the threshold for distance D can be a percentage (such as 50%, 25%, 10%, or 5%) of an overall length L or width W of the object. In the foregoing examples, pairing of suspect vertices V 5 and V 10 is based on a predetermined criteria, such alignment and/or proximity. In addition or alternatively, other criteria can be used, such as similarity in the curvature of legs adjacent to the suspect vertices (e.g., legs L 5 and L 10 ), similarity in image pixel color of legs adjacent to the suspect vertices, and/or presence of a light transmittance boundary line at the suspect vertices. Light transmittance boundary lines 40 are described below.
[0035] Optionally, other suspect vertices can be paired by a process of elimination. For example, after suspect vertices V 5 and V 10 are paired in object 10 A, the only remaining suspect vertices are V 3 and V 12 . In this situation where there are exactly two remaining suspect vertices, suspect vertices V 3 and V 12 are automatically identified by processor 16 as a suspect vertex pair and as an intersection between two separate pieces 30 and 32 ( FIG. 2 ).
[0036] Referring to FIG. 4 , outline 26 B of object 10 B has only one suspect vertex. That is, outline 26 B has only one vertex (V 3 ) having an interior angle Φ that is greater than the threshold or an exterior angle θ that is less than the threshold. In some embodiments, since the total number of suspect vertices for object 10 B is exactly one, processor 16 identifies that vertex (V 3 ) as not being an intersection between two separate pieces. Processor 16 concludes that object 10 consists of a single piece 34 ( FIG. 2 ).
[0037] On the other hand, outline 26 C of object 10 C has exactly two suspect vertices. That is, vertices V 1 and V 5 each have an interior angle Φ that is greater than the threshold or an exterior angle θ that is less than the threshold. In some embodiments, since the total number of suspect vertices for object 10 C is exactly two, processor 16 identifies those vertices (V 1 and V 6 ) as a suspect vertex pair and as an intersection between two separate pieces 36 and 38 ( FIG. 2 ).
[0038] In object 10 C, piece 36 is actually a piece of translucent glass, and piece 38 is actually a piece of opaque, non-glass debris material. This composition can be determined by processor 16 as follows. The opacity of piece 38 results in light transmittance boundary line 40 ( FIG. 4 ) within outline 26 C. The light transmittance boundary line 40 can arise when, for example, no light or very little light passes through the opaque, non-glass debris material. Processor 16 detects light transmittance boundary line 40 as an abrupt change in light intensity passing through object 10 C captured in image 18 . Light transmittance boundary line 40 has endpoints 40 E at suspect vertices V 1 and V 5 . Additionally or alternatively, since endpoints 40 E are located at suspect vertices V 1 and V 5 , processor 16 identifies those vertices (V 1 and V 5 ) as a suspect vertex pair and as an intersection between two separate pieces 36 and 38 ( FIG. 2 ) and does not mistakenly identify piece 36 as a piece of glass with a label. Further evaluation by processor 16 , as described below, will reveal piece 36 as a piece of glass and piece 38 as non-glass debris material.
[0039] Referring again FIG. 4 , outline 26 D of object 10 D has no suspect vertex. That is, none of vertices V 1 to V 5 have an interior angle Φ that is greater than the threshold or an exterior angle θ that is less than the threshold. In some embodiments, since the total number of suspect vertices for object 10 D is exactly zero, processor 16 concludes that object 10 D consists of a single piece 42 ( FIG. 2 ). Piece 42 is actually a single piece of glass with a label L, as shown in FIG. 2 . This can be determined by processor 16 as follows. Label L is a piece of paper, opaque plastic, or foil which is adhered on the surface of piece 42 . Label L results in light transmittance boundary line 40 . The light transmittance boundary line 40 can arise when, for example, no light or very little light passes through label L. Processor 16 determines that endpoints 40 E of light transmittance boundary line 40 are not located at any suspect vertex. Additionally or alternatively, since endpoints 40 E are not located at any suspect vertex, processor 16 concludes that object 10 D consists of a single piece of glass 42 with label L and does not mistakenly conclude that object 10 D contains a piece of non-glass debris material.
[0040] Referring again to FIG. 3 , the characteristic of the object can be determined (block 50 ) after the composition of the object has been determined (block 20 ). As described above, when processor 12 concludes that the object is a single piece of material, it can deduce that the single piece is a piece of glass with a label based, at least, on the presence of a light transmittance boundary line within the outline of the object. To evaluate other characteristics, processor 12 analyzes image 18 to determine, for each piece contained within the object, color type, material type, and/or whether the piece is a piece of glass with a label.
[0041] After concluding that object 10 A consists of three pieces, processor 12 determines areas of possible overlap that might lead of inaccurate analysis. The areas of possible overlap are areas between suspect vertex pair V 5 , V 10 and between suspect vertex pair V 3 , V 12 ( FIG. 5 ). In some embodiments, processor 12 analyzes areas of image 18 adjacent to a vertex which is not a suspect vertex. For example, processor can analyze image areas adjacent to vertices V 6 , V 4 , and V 2 to determine the color type of each of glass pieces 28 , 30 , and 32 respectively.
[0042] Additionally or alternatively, after concluding that object 10 C consists of two pieces, processor 12 analyzes areas of image 18 adjacent to points P on the outline and located at a distance away from suspect vertex pair V 1 , V 5 ( FIG. 4 ). Selection of areas at a distance away from suspect vertices V 1 and V 5 can help avoid areas of possible overlap that could lead of inaccurate analysis.
[0043] After the composition (i.e., number of items) of each object is determined, the characteristics (e.g., color type, presence of non-glass debris, and presence of labels adhered to glass) of individual pieces in each object can be determined using system and methods known in the art, in addition to or as alternatives to the methods described above. See, for example, U.S. Pat. No. 5,314,071 issued to Christian et al., entitled “Glass Sorter.”
[0044] Imaging device 12 , processor 16 , and light source 14 can be implemented to perform quality tests on the cullet output of a glass sorter.
[0045] In FIG. 6 , glass sorter 44 is configured to sort a mixture of glass pieces 45 by color type and eject a separate cullet output stream 46 A, B, C for each glass color type. For example cullet output stream 46 A can be a stream of green cullet, output stream 46 B can be a stream of amber (or brown) cullet, and output stream 46 C can be a stream of clear (or flint) cullet. Glass sorter 44 includes conveyor belt 48 which transports the mixture of glass pieces 45 to sorting assembly 50 .
[0046] Sorting assembly 50 produces output streams 46 A, B, C. Sorting assembly 50 includes sensor modules 52 and light modules 54 directed toward sensor modules 52 . Sensor modules 52 are used to determine the color type of the glass pieces which fall from the edge of conveyor belt 48 . Sorting assembly 50 includes actuators 56 controlled by control module 60 which is communicatively coupled to conveyor belt 48 , sensor modules 52 , and light modules 54 . Actuators 56 can be pneumatic blowers, mechanical gates, or electrostatic plates. Actuators 56 are configured to push or guide selected glass pieces into a selected one of the output streams 46 A, B, C based upon analysis of data from sensor modules 52 by control module 60 . In the illustrated embodiment, sensor modules 52 are located above free-fall trajectory 58 of mixed glass material 45 . The number, arrangement and orientation of sensor modules 52 , light modules 54 , and actuators 56 can be different from what is illustrated. The sensor modules, light modules, and actuators can be as described in U.S. Pat. No. 7,351,929, U.S. Pat. No. 7,355,140, or U.S. Pat. No. 8,436,268. The entirety or a portion of glass sorter 44 can be as described in U.S. Pat. No. 5,314,071.
[0047] Tests on the quality of the cullet output of glass sorter 44 ( FIG. 6 ) can be performed using quality test modules 62 which are configured to determine the composition and characteristics of objects as described in connection with FIGS. 1-5 . Transporters 64 move cullet from each of output streams 46 A, B, C to quality test modules 62 . Each transporter 64 can be a conveyor belt, a rotating feed wheel, a pivoting diverter plate, or similar device. Each quality test module 62 includes imaging device 12 , processor 16 , and light source 14 previously described (see FIGS. 1-5 ). Each transporter 64 slides or drops cullet pieces (for example, objects 10 A- 10 D in FIG. 1 ) between imaging device 12 and light source 14 . Processor 16 provides an indication of the purity of the cullet. For example, processor 16 can indicate that the amber cullet output from glass sorter 44 satisfies or fails to satisfy a predetermined quality requirement, such as at least 95% amber glass by weight. As another example, the predetermined quality requirement can be that any of the cullet output must be less than 2% non-glass debris material by weight with the remainder being at least 95% by weight of the desired color type. Each quality test module 62 optionally includes output module 66 which provides the indication of purity. Output module 66 can be a display screen or printer that shows the purity level. Alternatively, output module 66 can be an audio or visual alarm configured to automatically alert the person who is operating glass sorter 44 .
[0048] In the illustrated embodiment, there are three quality test modules 62 . One quality test module 62 is dedicated for each cullet collection area 47 A, B, C. In other embodiments, sorter 44 is configured to sort more than three color types and output a corresponding number of cullet output streams. There can be a separate quality test module for each cullet collection area. Alternatively, there can be only one quality test module which is movable between various cullet collection areas.
[0049] In FIG. 6 , the quality test modules 62 are shown at fixed locations at the end of each cullet output streams. In other embodiments, there is no quality test module at a fixed location. For example, there can be a quality test module that is stored at a location away from the cullet output streams. When needed, a sample quantity can be taken from a cullet output stream and then carried by a person to quality test module so that a quality test can be performed.
[0050] In some embodiments, one or more of the quality test modules 62 are communicatively coupled to control module 60 of glass sorter 44 . Control module 60 is configured to alter the operation of glass sorter 44 based on output signals from quality test module 62 . For example, if the predetermined quality requirement is not met, processor 16 within quality test module 66 automatically causes control module 60 to stop conveyor belt 48 and other machinery in glass sorter 44 to allow for maintenance or adjustments to the machinery. As another example, if the predetermined quality requirement is not met, processor 16 within quality test module 66 automatically causes control module 60 to change one or more glass sorter parameters to increase the purity level of the cullet. Glass sorter parameters include without limitation the speed of conveyor belt 48 , the rate at which mixed glass is place onto conveyor belt 48 , and settings for suctioning and/or filtering out non-glass debris from the mixture of glass material 45 .
[0051] In some embodiments, one or more of the quality test modules 62 are configured or programmed to performed the above-described tests on the quality of cullet at random times or at fixed time intervals. In the case of fixed time intervals, tests can be performed every 5 minutes, or every 10 minutes, or every 30 minutes, or other time duration. In the case of testing at random times, the time interval between tests is not fixed, and the time intervals of many tests can be specified to provide an average time interval. For example, tests can be performed randomly such a first time interval is 32 minutes, followed by a second time interval of 15 minutes, and followed by a third time interval of 18 minutes, and so on, such that all time intervals result in an average time interval. The average time interval between tests is 5 minutes, 10 minutes, 30 minutes, or other time duration. Optionally, one or more of the quality test modules 62 are further configured or programmed such that, when the predetermined quality requirement is not met, the quality test modules 62 automatically increase the frequency of testing. For example, the quality test module 62 may automatically reduce the fixed time interval or the average time interval. Increasing the frequency of testing provides a greater number of data points for characterizing the quality of the cullet.
[0052] Additionally or alternatively, one or more of the quality test modules 62 are configured or programmed such that, when the predetermined quality requirement has been met and exceeded, the quality test module 62 automatically decreases the frequency of testing. For example, the quality test module 62 may automatically increases the fixed time interval or the average time interval.
[0053] In some embodiments, sorting assembly 50 can determine the composition and characteristics of objects as described in connection with FIGS. 1-5 . For example, imaging device 12 , processor 16 , and light source 14 (all of which were described in connection with FIGS. 1-5 ) can be implemented to perform sorting within sorting assembly 50 of glass sorter 44 . Within sorting assembly 50 , sensor modules 52 can include or be replaced with imaging devices 12 , light modules 52 can include or be replaced with light sources 14 , and control module 60 can include or be replaced with processor 16 .
[0054] In some embodiments, there are one or more memory components which form a computer readable medium. The computer readable medium may be volatile or non-volatile. Examples of a computer readable medium include without limitation a magnetic storage device (e.g., computer hard drives), an optical storage device (e.g., a CD-ROM and DVD-ROM), or a flash memory device (e.g., memory cards and USB flash drives). Processor 16 and/or control module 60 may include the computer readable medium. Alternatively, processor 16 and/or control module 60 may be communicatively coupled to another device capable of reading the computer readable medium.
[0055] The computer readable medium has a stored computer program embodying instructions, which when executed by a computer (e.g., processor 16 and/or control module 60 , or other computer) causes the computer to evaluate a mixture of glass pieces according to the process steps described herein, including process steps described in connection with any of FIGS. 1-6 . The computer readable medium includes instructions for performing the process steps described herein, including process steps described in connection with any of FIGS. 1-6 .
[0056] While several particular forms of the invention have been illustrated and described, it will also be apparent that various modifications can be made without departing from the scope of the invention. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.
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A mixture of glass pieces can be evaluated by taking an image of an object from the mixture. The object has the possibility of being either a single piece of glass from the mixture or at least two pieces of glass from the mixture. By knowing how many pieces of glass are in each object, the accuracy of the evaluation can be improved. Angles of an outline of the object are determined from the image, and then the angles are evaluated to determine whether the object is at least two pieces. When it is determined that the objection is at least two pieces, it is possible to assign a characteristic, such as color type or material type, for each piece as opposed to assigning the same characteristic to the entire object.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for manufacturing carbon having good resistance to oxidation.
2. Description of the Prior Art
Great hopes are set on carbon material as a high-temperature material since the strength of carbon material is not lowered at a high temperature of 1000° C. or more, and the carbon material has a high heat conductivity.
However, when a temperature of air exceeds 500° C., the carbon material in the air becomes unfit for use since it is oxidized and becomes unfit for use. Therefore, as a method for preventing the oxidation of the carbon material at a high temperature, a method, wherein the carbon material is used in an inert atmosphere, or a method, wherein the carbon material can be used in the atmosphere of high temperature by forming an oxide protective coating on the surface of the carbon material by the use of a chemical deposition method, is known. There is also known a method wherein a surface layer of the carbon material is converted to silicon carbide by reacting the surface layer of the carbon material with silicon monoxide gas at a high temperature. Sintered carbon coated with silicon carbide is widely used for a crucible for withdrawing a single silicon crystal or a susceptor for epitaxial growth or the like in the fields related to semiconductors.
Carbon materials of a porous body having heat resistance and resistance to oxidation are also industrially useful material. Great hopes are placed on a porous carbon body as a porous board for surface combustion, or a heat transfer element releasing heat, which is obtained by means of convective heat or transfer, by means of heat transfer by radiation, or a filter for dust containing gas of high temperature. For this purpose, a high porosity of 40 to 80 vol. % is required. In this case, it is clear that only the surface coating of the porous carbon body is not sufficient. The carbon material for those porous bodies and the prior art methods for coating the porous bodies will now be described.
The carbon material for the porous body is usually manufactured from carbon fiber as a material. The carbon fiber is used in the form of a long fiber of 3 to 20 μm in diameter or in the form of a short fiber obtained by cutting the carbon fiber so that a ratio of the diameter of the short fiber to the length thereof can be from 3 to 50. In the case of the long fiber, a preform obtained by weaving the long fiber in two dimensions or three dimensions is prepared. In the case of the short fiber, a preform is prepared by the use of a shape-keeping property of the short fibers which are entwined with each other.
It is known that since the strength of such preform is small and the resistance to oxidation of the preform at a high temperature is bad, the surfaces of fibers are coated with silicon carbide for the purpose of connecting the fibers with each other and imparting resistance to oxidation to the fibers. The following method is disclosed, for example, in a Japanese Patent Publication Laid Open No. 167290/89:
A high molecular organic silicon compound is impregnated into a preform. The high molecular organic compound is converted to silicon carbide by subjecting the high molecular organic compound to a heat treatment. A coating of silicon carbide or silicon nitride is formed on the surface of silicon carbide by means of a chemical vapor phase deposition method. In the case of coating the preform with silicon carbide, polycarbosilane, polysilostyrene or the like, which is converted to silicon carbide by means of a heat treatment at a temperature of 1000° to 1600° C., is used as a high molecular organic chemical compound of silicon, with which the first layer of the preform is coated. A mixed gas of methyltrichlorosilane, hydrogen and argon is used as a material for silicon carbide, with which the second layer is coated, and those gases are reacted with each other at a temperature of 1000° to 1650° C. In the case of the layer of silicon nitride, a mixed gas of silicon tetrachloride, ammonia, hydrogen and argon is used. In this way, a porous body having not only heat resistance, but also resistance to oxidation can be obtained.
Subsequently, the problems of the prior art methods for manufacturing carbon material having good resistance to oxidation, mainly the problems of the coats in the prior art methods will now be described.
In the foregoing chemical deposition method, since silicon carbide forms layers on the surface of the sintered carbon body or the carbon material of the porous body, silicon carbide insufficiently adheres to the surface of the sintered carbon body or the carbon material. Moreover, since there is a difference in the thermal expansion coefficients between silicon carbide and the sintered carbon body or the carbon material, the base carbon material can be oxidated or impaired by flaking or cracking of coating layers due to repeated heating and cooling. In a conversion method, coating layers of good adhesiveness can be obtained, but this method requires a high temperature of 1700° C. or more, which causes a problem of equipment and operation. Further, a problem of the source of silicon which is supplied in the form of gas is posed as a problem common to the chemical deposition method and the conversion method.
SUMMARY OF THE INVENTION
It is an object of the present invention to manufacture carbon material having good resistance to oxidation.
To attain the above-mentioned object, the present invention provides a method for manufacturing carbon material having good resistance to oxidation, comprising the steps of:
coating carbon material with an inorganic polysilazane;
heating said carbon material coated with the inorganic polysilazane in an inert atmosphere, amorphous silicon nitride being formed on the surface of said carbon material; and
reheating said heated carbon material in a non-nitriding and non-oxidizing atmosphere, silicon carbide being formed on the surface of said carbon material.
The above objects and other objects and advantages of the present invention will become apparent from the detailed description which follows, taken in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a graphical representation showing the relationship between a partial pressure of nitrogen and a heating temperature which can accomplish the non-nitriding atmosphere according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present inventors made a great effort to attain the aforementioned object. As a result, the present inventors have found that a strong coat high in resistance to oxidation can be formed on the surface of the carbon material by coating the carbon material with inorganic polysilazane, heating the carbon material in a non-nitriding and non-oxidizing atmosphere, and forming layers of silicon carbide on the surface of the carbon material, and have completed the present invention.
The shape of the carbon material is determined depending on the use of the carbon material and is specifically not limited. To clean the carbon material and to improve wettability of the carbon material, the carbon material can be washed by an organic solvent such as dichloromethane or the like and coated with inorganic polysilazane.
The sintered carbon body is obtained by forming, sintering and graphitizing material such as natural graphite, artificial graphite, carbon black, coke pitch, carbon fibers or the like. Carbides such as TiC, ZrC, NbC, or B 4 C or boride such as TiB 2 , or ZrB 2 can be added to the carbon material as a sintering assistant. Further, the density of the carbon material can be increased by impregnating pitch into the carbon material after sintering of the carbon material and by making a carbonation sintering of the carbon material.
It is good if the density of said sintered body is high. The apparent density of the sintered body is desired to be 1.6 g/cm 3 or more. It is understood that, when the density of the sintered body is below 1.6 g/cm 3 , the surface shape of the sintered body becomes complicated, when it is examined with a microscope. In consequence, it is difficult to completely coat the surface of the sintered body with silicon carbide and to seal off the base carbon material from the atmospheric gas.
The porous carbon body can be a textile woven by long fiber in two dimensions or three dimensions or a compact formed by using the shape-keeping property of short fibers entwined with each other. When a sufficient shape-keeping property of the short fibers cannot be obtained, an organic or inorganic binder can be added to the compact of the short fibers as a forming auxiliary. The carbon fibers can be of either PAN (polyacrylonitrile) group or of pitch group. The diameter of the fibers is specifically not limited, but desired to be from 3 to 20 μm.
In the case of the carbon fiber, it is clear that since the peripheries of fine fibers are exposed to the atmosphere, the fibers deteriorate more susceptibly under the influence of the atmosphere than a block-shaped sintered body. In this connection, the diameter of the fibers is desired to be larger. There is, however, the lowest limit, which is determined by the decrease of strength of the porous body in connection with the deterioration of the coat and by an expected service life of products. As a result of tests, the aforementioned lowest limit was estimated at 3 μm.
On the other hand, when the diameter of the fibers is over 20 μm, the area of the surfaces, on which the fibers contact each other, is small. Therefore, the connection of the fibers with each other by means of silicon carbide is insufficient, by which only a porous body having a low strength is obtained. The strength of the carbon porous body can be enhanced by increasing the packing density of the fibers. In this case, however, the porosity of the porous body is lowered, by which the function of the porous body is impaired.
In the case of the short fibers, the ratio of the diameter of the fiber to the length thereof is preferred to be 3 to 50. When the ratio is below 3, only a low porosity is obtained. When the ratio is over 50, the fibers are liable to be converted to lumps, being entwined with each other, before forming of the fibers. Therefore, it is difficult to form a compact having pores of a uniform diameter.
Inorganic polysilazane is an elastomer obtained by diluting chlorosilane H 4-a SiCl a (a=1, 2, 3, 4) in a solvent and reacting it with ammonia (NH 3 ). In the method of the present invention, inorganic polysilazane can be produced by using H 2 SiCl 2 as a material or by using a mixture of heterogeneous chlorosilane with H 2 SiCl 2 as a main component. Inorganic polysilazane in the state of a liquid at ordinary temperatures is favorable. For example, polysilazane having structures such as [H 2 SiNH] x , or [H 2 SiNH] x .(H 2 Si) 1 .5 N] y is used. Such inorganic polysilazane can be used as it is as a coating liquid. Inorganic polysilazane can be used as a coating liquid by diluting it with a solvent. Benzene, diethylether, dichloromethane, tetrahydrofuran, pyridine or the like is used as the solvent. The structures, compositions and molecular weight of inorganic polysilazane synthesized vary somewhat depending on the sorts of the solvents. However, although any of them is used, inorganic polysilazane consists of hydrogen, nitrogen and silicon, and does not contain carbon.
The degree of dilution of chlorosilane in the solution is affected by the ease of permeation of chlorosilane into the carbon material and by the thickness of the liquid layers formed on the surface of the carbon material. Therefore, the this degree is unconditionally not determined. However, the concentration of 1 to 80 wt. % of the solution is regarded as appropriate by experience. When the concentration of the solution exceeds 80 wt. %, dried layers of inorganic polysilazane becomes thin, by which the base material are liable to be exposed. The thickness of the dried layers of around 40 to 200 μm is appropriate.
In the case of the thickness of the dried layers of less than 40 μm, when inorganic polysilazane is converted to silicon carbide, being heated, the thickness of silicon carbide is insufficient and cannot obtain a predetermined resistance to oxidation. When the thickness of the dried layers exceeds 200 μm, the dried layers of said silicon carbide become breakable, by which the layers can separate from the base material.
The entire surface of the sintered carbon body can be coated with inorganic polysilazane, or only a portion of the sintered carbon body, which is liable to be oxidized, being exposed during the use of the sintered carbon body, can be coated. The method for coating, wherein the sintered carbon body is coated with the aforementioned coating liquid, is specifically not limited. The coating liquid can be applied by a brush, or immersion of the sintered carbon body into the coating liquid or the like. When the sintered carbon body is previously degassed, immersed into the coating liquid, and the sintered carbon body immersed into the coating liquid is pressurized, the coating liquid permeates well into the pores of the sintered carbon body, by which a good coat without exposure of the base material can be obtained.
In the case of the porous carbon body manufactured from the carbon fiber, the aforementioned coating liquid can be made to permeate into the porous carbon body under pressure. The coating liquid can be made to suck into the pores of the porous carbon body, which are kept vacuous. The method for sucking the coating liquid into the pores of the porous carbon body is favorable since the coating liquid can be made to sufficiently permeate into the small pores formed in the porous body, where the carbon fibers contact each other, by keeping a high pressure for a predetermined period of time after the sucking of the coating liquid.
The applied pressure of 5 to 5000 kg/cm 2 is appropriate. When the pressure is below 5 kg/cm 2 , the coating liquid does not permeate sufficiently into among the surfaces of the fibers. When the pressure is 5000 kg/cm 2 , the coating liquid permeates sufficiently not only into among the surfaces of the fibers, but also into the pores of the fibers. The higher the pressure, the better the permeation of the coating liquid. However, when the pressure is increased to more than 5000 kg/cm 2 , it is difficult to obtain a pressure apparatus, which increases equipment cost.
The treatment carried out after the carbon material have been coated with the aforementioned coating liquid will now be described.
The carbon material coated with the coating liquid is heated in an inert atmosphere by the use of a heating furnace which can regulate the atmosphere. Initially, the solvent is evaporated. Then, polysilazane begins to be decomposed by heat at a temperature of around 150° C. The heat decomposition of polysilazane terminates substantially at a temperature of around 600° C., and amorphous silicon nitride can be obtained. The aforementioned inert atmosphere can be obtained by charging helium, neon or argon into the heating furnace.
After the coating liquid has been decomposed by heat and amorphous silicon nitride has been obtained, the heat treatment is applied to the carbon material in an inert atmosphere at a high temperature. In this case, the aforementioned heating furnace can be used as it is. However, since the heating temperature is high and it takes much time for the heat treatment, another furnace is often desired to be used as the sintering furnace.
The aforementioned inert atmosphere is a non-nitriding and non-oxidizing atmosphere. Said non-nitriding atmosphere means an atmosphere having a sufficiently low partial pressure of nitrogen. Nitrogen gas is released when amorphous silicon nitride, to which inorganic polysilazane has converted, reacts with carbon as a base material and generates silicon carbide. Nitrogen gas is not prevented from being released in an atmosphere having a sufficiently low partial pressure of nitrogen. The partial pressure of nitrogen is 0.1 atm. at 1300° C. and 20 atm at 1900° C., and the partial pressure of nitrogen is desired to be kept within the range shown with oblique lines in FIG. 1. FIG. 1 is a graphical representation showing the relationship between the partial pressure of nitrogen and the heating temperature.
The non-oxidizing atmosphere is in the atmosphere wherein oxide gas such as oxygen, moisture or the like are substantially not contained in said atmosphere, and the generation of silicon monoxide can be ignored at a heating step, at which the layers of silicon carbide are formed.
Inert gas such as helium, neon and argon or hydrogen gas is desired as the atmospheric gas which forms the non-nitriding and non-oxidizing atmosphere during the heating. The pressure of around 10 -4 to 100 atm. is appropriate. The heating temperature of 1300° to 1900° C. in the non-nitriding and non-oxidizing atmosphere is appropriate. When the heating temperature is below 1300° C., the reaction rate is small, which is not put to practical use. When the heating temperature exceeds 1900° C., the phenomenon such that silicon as silicon monoxide gas is vaporized by a very small amount of oxygen inevitably mixed into the atmosphere cannot be ignored. Therefore, the loss of silicon increases.
The time of the heating can be a time enough to form the layers of silicon carbide. The time of the heating can be around 5 to 20 hours at 1300° C., and 0.5 to 5 hours at 1900° C.
According to the present invention, the layers are formed on the surface of the carbon material by liquid inorganic polysilazane, carbon on the surface of the carbon material is converted to silicon carbide by the reaction of said polysilazane with carbon in the base carbon material, and layers of silicon carbide with good adhesiveness can be effectively formed. According to the aforementioned method, in addition to the heat resistance which carbon has originally, the carbon material having the resistance to oxidation at a high temperature can be manufactured.
EXAMPLE 1
A sintered isotropic graphite body of 2.01 gr/cm 3 in apparent density of 50 mm in breadth, 50 mm in length and 10 mm in thickness was immersed into dichloromethane and left as it is for 24 hours. Thereafter, it was taken out and dried. This sintered body was put into a vessel of silicon rubber. The vessel with the sintered body therein was evacuated to 10 -2 Torr. Inorganic liquid polysilazane was introduced into said rubber vessel, and the sintered body was immersed into the liquid inorganic polysilazane. The pressure inside the vessel was increased to the atmospheric pressure. A lid of silicon rubber was attached to said rubber vessel and said rubber vessel was sealed. A pressure of 5000 kg/cm 2 was applied on the vessel from the outside of the vessel by the use of a cold static hydraulic press. Thereafter, the treated sintered body was taken out of the vessel. The treated sintered body was put into a heating furnace and heated therein. The temperature inside the heating furnace was raised to 600° C. at a rate of 10° C./min. The sintered body was kept as it was in the heating furnace for one hour and naturally cooled. Successively, the sintered body was put into a sintering furnace. The temperature inside the sintering furnace was elevated to 1500° C. in an atmosphere of argon at room temperature at a rate of 30° C./min. 5 hours later, the sintered body was naturally cooled. For a test, when this sintered body was kept in the atmosphere at 1200° C. for 100 hours, it was found that the weight of the sintered body increased by only 2.2 wt. %, but there was no change except for the increase of the weight.
EXAMPLE 2
A coating liquid of 50 wt. % inorganic polysilazane and 50 wt. % dichloromethane was regulated, and the same operation as that in the Example 1 was carried out for the sintered isotropic graphite body of 50 mm in breadth, 50 mm in length and 10 mm in thickness. It was found in the above-mentioned test that the weight of the sintered body increased by 0.20 wt. %. Except for the increase of the weight of the sintered body, there was no change.
EXAMPLE 3
Long fibers of 7 μm in diameter of PAN group were woven in two dimensions and stacked in layers, by which a sheet of 2.8 mm in thickness, 100 mm square and 0.72 g/cm 3 in apparent density was obtained. This sheet was immersed into dichloromethane and kept as it was for 24 hours. Then, this sheet was taken out of dichloromethane and dried. The sheet was degassed to 10 -2 Torr in a vacuum in the vessel of silicon rubber. Liquid inorganic polysilazane as the coating liquid was introduced into said rubber vessel, into which the sheet was immersed. Said rubber vessel was sealed by a cover of silicon rubber. After a pressure of 5000 kg/cm 2 had been applied from the outside of the vessel on the vessel, the sheet treated was taken out of the vessel, by which an impregnant was obtained. The impregnant was put into the heating furnace, and heated up to 600° C. at a rate of 10° C./min. The impregnant was kept as it was for one hour. Thereafter, it was naturally cooled. Successively, the impregnant was put into the sintered furnace, and heated up to 1500° C. in an atmosphere of argon of the atmospheric pressure. 5 hours later, the impregnated body was taken out of the sintering furnace and naturally cooled, by which a porous body was obtained. This porous body has the apparent density of 0.89 g/cm 3 . Although the porous body was kept as it was for 100 hours in the atmosphere at 1200° C. for a test, the weight of the porous body increased by only 0.31 wt. %.
EXAMPLE 4
Short fibers of 7 μm in diameter of PAN group were dispersed in dichloromethane by the use of supersonic waves so that the content of the short fibers in dichloromethane can be 5 vol. %. Immediately, dichloromethane with the short fibers dispersed therein was cast into a die. A porous disk of resin of 30 mm in diameter, which has a communicating pores of 50 to 200 μm was inserted into the die. Dichloromethane was pressed out by the use of a ram through the porous disk by pressing dichloromethane from above at a pressure of 200 kg/cm 2 . Dichloromethane was taken out and dried, by which a preform of 3 mm in thickness and 30 mm in diameter was obtained. The apparent density of the preform was 0.81 g/cm 3 . On the other hand, the coating liquid was regulated by dissolving 80 wt. % liquid inorganic polysilazane into 20 wt. % dichloromethane.
The aforementioned preform was put into the vessel of silicon rubber. The pressure inside the vessel was reduced to 10 -2 Torr. The foregoing coating liquid was impregnated into the preform by introducing the coating liquid into the aforementioned rubber vessel. Subsequently, said rubber vessel was sealed with a cover of silicon rubber. A pressure of 5000 kg/cm 2 was applied from the outside of the vessel on the vessel, and the preform treated was taken out of the vessel, by which an impregnant was obtained. The impregnated body was heated in the heating furnace. The heating temperature was elevated up to 100° C. at a rate of 10° C./min. The impregnated body was kept as it was for one hour. The heating temperature was again elevated up to 600° C. The impregnated body was kept as it was for one hour. Thereafter, the impregnated body was taken out of the heating furnace and cooled naturally. Successively, the impregnated body was put into the sintering furnace and heated. The heating temperature was elevated up to 1500° C. at a rate of 30° C. in an atmosphere of argon of the atmospheric pressure, and 5 hours later, the impregnated body was naturally cooled, by which a sintered porous body was obtained. This sintered body has an apparent density of 1.02 g/cm 3 . Although the sintered body was kept as it was for 100 hours in the atmosphere at 1200° C. for the test, the weight of the sintered body increased by only 0.25 wt. %.
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A method for manufacturing carbon material having good resistance to oxidation, comprising coating carbon material, which is a sintered body or a porous body, with an inorganic polysilazane; heating the carbon material coated with the inorganic polysilazane in an inert atmosphere to form amorphous silicon nitride on the surface of the carbon material; and reheating the heated carbon material in a non-nitriding and non-oxidizing atmosphere, the amorphous silicon nitride being decomposed and silicon carbide being formed on the surface of the carbon material; the reheating being conducted at a temperature of 1300° C. to 1900° C. and the non-nitriding and non-oxidizing atmosphere having a partial pressure of nitrogen determined with reference to a graph wherein the abscissa is a temperature in °C. and the ordinate is partial pressure of nitrogen in atmospheres, the partial pressure being defined within an area under a line connecting a first point corresponding to 1300° C. and 0.1 atmospheres and a second point corresponding to 1900° C. and 20 atmospheres.
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This application claims benefit of U.S. Provisional Application Serial No. 60/028,247, filed Oct. 9, 1996, entitled "Lathe Reference Stop And Combination Tool."
BACKGROUND OF THE INVENTION
This invention relates generally to a reference stop for use in a lathe for providing a fixed surface from which measurements can be made for applying tools to a workpiece being worked in the lathe.
Lathes are typically provided with a chuck which is used to grip raw stock to be worked, and means for rotating the chuck at a high rate of speed, which can approach thousands of revolutions per minute ("RPM "). A draw tube may be connected to the chuck for rotation with the chuck. Raw stock passes through the draw tube and is engaged by the chuck during operation of the lathe.
Typically, raw stock is inserted through one end of the machine through the draw tube, and then on through the chuck, where the stock is gripped. However, although the workstock is typically inserted into the backside of the chuck through the draw tube, in certain operations it is necessary to insert the stock directly into the front side of the chuck and on into the draw tube. This is necessary when the stock must be worked at a particular point along its length, and that length dimension, as measured from the end of the stock now within the draw tube, must be accurately measured. A common method of measuring this point is through a simple trial and error approach. The stock is repeatedly inserted through the front end of the chuck into the draw tube and tightened down, and measurements taken until the correct distance from the free end of the workstock to the working point of the lathe tool to be used is found. This can be a tedious, cumbersome, and time-consuming endeavor and reduces the efficiency of operation of the lathe, and further, increases labor costs associated with production. Other means have included devices for attachment of a reference stop to the draw tube. However, because in conventional lathes the draw tube moves rearwardly during the tightening of jaws of the chuck when gripping the stock, and forwardly to loosen the chuck jaws, such reference stops can become difficult to adjust to the proper reference distance.
Accordingly, there exists a need for a means for facilitating setup of stock within a chuck to present a predetermined point of the stock to a desired lathe tool.
SUMMARY OF THE INVENTION
It is, therefore, the principal object of this invention to provide a lathe reference stop for use in positioning workstock in a desired location.
Still another object of the present invention is to provide a lathe reference stop which can readily be used on a conventional lathe.
Another object of the present invention is to provide a combination tool for use in connection with a lathe reference stop constructed in accordance with the present invention.
Yet another object of the present invention is to provide a lathe reference stop and combination tool which are usable in conjunction with one another on a conventional lathe.
Generally, the present invention includes a backstop to be used in a lathe when a piece of workstock must be worked at a predetermined distance from a reference end of the stock. The backstop is adjustable and is provided with a stop tube, the stop tube having a flange which fixedly connects the stop tube to a conventional chuck on the lathe. A threaded shaft adjustment is attached to the backstop for moving the backstop within the sleeve, and the threaded shaft includes a profiled end.
The present invention also includes a tool for insertion into the open end of the draw tube of the lathe. The tool includes a cooperating socket member for engaging the profiled end of the threaded rod. This allows for the threaded rod to be turned to adjust the backstop, while the backstop is installed within the lathe, to therefore move the backstop to a desired reference distance from the chuck.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing, as well as other objects of the present invention, will be further apparent from the following detailed description of the preferred embodiment of the invention, when taken together with the accompanying specification and the drawings, in which:
FIG. 1 is a perspective view of a conventional lathe;
FIG. 2 is an exploded view of a lathe reference stop constructed in accordance with the present invention;
FIG. 3 is an exploded view, with parts cut away, of a lathe reference stop and combination tool constructed in accordance with the present invention;
FIG. 4 is a sectional view of a lathe reference stop constructed in accordance with the present invention;
FIG. 5 is a partial sectional view of a lathe reference stop constructed in accordance with the present invention, installed in a lathe;
FIG. 6 is a sectional view of an alternate embodiment lathe reference stop constructed in accordance with the present invention;
FIG. 7 is a partial sectional view of an extension which can be added to a lathe reference stop constructed in accordance with the present invention; and
FIG. 8 is an exploded view of an alternate embodiment of a combination tool constructed in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The accompanying drawings and the description which follows set forth this invention in its preferred embodiment. However, it is contemplated that persons generally familiar with lathes and lathe tools will be able to apply the novel characteristics of the structures illustrated and described herein in other contexts by modification of certain details. Accordingly, the drawings and description are not to be taken as restrictive on the scope of this invention, but are to be understood as broad and general teachings.
Referring now to the drawings in detail, wherein like reference characters represent like elements or features throughout the various views, the lathe reference stop and combination tool of the present invention are indicated generally in the figures by reference characters 10 and 100, respectively.
Turning to FIG. 1, a lathe A is illustrated having an operator interface B and a chuck C. Extending rearwardly from chuck C is a draw tube D which terminates at its other end at the open end E of lathe A, into which raw stock S is generally inserted for production purposes. A tool work area W is provided in front of chuck C.
FIG. 2 illustrates the lathe reference stop 10 constructed in accordance with the present invention. The reference stop device 10 is inserted through opening O of chuck C, and includes a sleeve 12 to which a flange 14 is welded or attached by fasteners. Flange 14 includes bolt holes 18 through which bolts 20 pass for attaching flange 14 within a recess R of chuck C. When this is done, the conventional flange F provided with chuck C is removed, and sleeve 12 and flange 14 inserted in its place. Flange F is replaced on top of flange 14, after stop device 10 is inserted in draw tube D. Extending rearwardly from chuck C is draw tube D, which is mounted to chuck C, having flange G.
A threaded rod 22, having a profiled end 24, is provided on which jam nut 28 is threadingly connected. Jam nut 28 selectively fixes rotation of threaded rod 22 with respect to sleeve 12 (as shown in FIGS. 3 and 4). To advance threaded rod 32 inwardly or outwardly with respect to sleeve 12, threaded rod 22 is selectively rotated using profiled end 24. It is to be understood that while flange 14 is illustrated as being generally triangular in shape, it could be a variety of other shapes, as desired, in order to be fitted within a particular chuck C of a lathe A.
Provided within end 30 of sleeve 12 is threaded plate 34 which is fixedly connected within the interior of sleeve 12, as shown in FIGS. 3 and 4. Plate 34 can be fixed to sleeve 12 via welding, or through use of a set screw (not shown), or could be formed integrally with sleeve 12, if desired. Additionally, a threaded boss 38 can be provided, as shown in FIG. 3, in the end 30 of sleeve 12, if desired.
End 32 of threaded rod 22 is provided with a backstop, generally 44. As shown in FIG. 3, backstop 44 is a member which is fixed to threaded rod end portion 46 by a set screw 48. Backstop 44 can have a flat surface as illustrated by backstop 44', or could have a cylindrical recess 50 as illustrated with backstop 44". Further, a male stop, or alocator pin, generally 52, can be provided for use in connection with hollow workstock. Locator pin 52 can be fixed within recess 50 by any suitable means, including a set screw (not shown).
FIG. 5 illustrates reference stop device 10 inserted within a draw tube D of a lathe. Bushing 54, preferably attached to threaded rod 22, for example with a set screw 56, near end 46 supports end 46 within sleeve 12. Bushing 54 and backstops 44 are preferably constructed of a hard smooth material, such as nylon, metal, plastic, wood, etc.
Profiled end 24 of rod 22 is internally profiled, for example in an Allen socket manner, for receipt of an Allen-type end of the combination tool, generally 100, constructed in accordance with the present invention, shown in FIG. 3.
Combination tool 100 includes a crank member, generally 110, and a wrench member, generally 112. Crank member 110 includes a handle portion 114, and offset therefrom, an elongated shaft member 116. Shaft member 116 terminates in an Allen wrench-type head 117 for insertion into the Allen-type socket of profiled end 24 of rod 22. Although an Allen-type arrangement is illustrated for profiled end 24 of rod 22 and head 117 of wrench 112, other cooperating configurations could also be used, such as Torx, Phillips, slotted, or some other configuration or variation thereof. Profiled end 24 could also be a male connection, and head 117 a female connection.
Wrench 112 includes an elongated tube member 118 which terminates in a socket member 120. Socket member 120 is adapted to engage jam nut 28. Wrench member 112 also includes transverse handles 122, 124 for engagement by an operator during use, as described below.
Variations of the present invention are illustrated as alternate embodiments in FIGS. 6 through 8. In FIG. 6, O-rings 200 and 202 are provided. O-ring 200 is seated in a groove 204, provided about the circumference of the end of sleeve 12 opposite flange 14. The O-rings 200, 202 are preferably made from rubber, plastic, or some other elastomeric material. O-ring 200 engages with the inner surface of draw tube D to add further support of sleeve 12 in draw tube D.
O-ring 202 is provided in a circumferential groove 206 in bushing 54a. O-ring 202 serves to support and stabilize bushing 54a within sleeve 12 during operation.
A sleeve extension, generally 210 may also be provided. Sleeve extension 210 is of substantially the same diameter as sleeve 12 and includes an opened end 212 for receiving plate 34 of sleeve 12. Sleeve extension 210 includes an end plate 214 having a bore 215 therethrough for receipt of threaded rod 22. Jam nut 28 is used to bear against end plate 214 to force sleeve extension 210 against the end of sleeve 212 to thereby retain sleeve 210 in position.
Plate 214 may also include a circumferential groove 216 which carries an O-ring 218. O-ring 218 performs the same function as O-ring 200 (discussed in regards to the embodiment of FIG. 6) to support the terminal end of sleeve extension 210 against sleeve 12 within draw tube D.
The purpose of sleeve 210 is to support threaded rod 22 in the event threaded rod 22 extends a significant distance outwardly from the end of sleeve 12. Because threaded rod 22 and sleeve 12 rotate with the chuck at a high rate of speed, sleeve 210, by supporting that portion of threaded rod 22 extending outwardly beyond plate 34, keeps the end of threaded rod 22 from orbiting or whirling around within draw tube D.
FIG. 8 illustrates the use of C-shaped centering bushings 220 for use with wrench 112. Annular grooves 222 are provided in the wall of wrench 112 such that bushings 220 seat therein. Bushings 220 could be of a variety of designs, but are preferably constructed of nylon, plastic, or some other suitable material and are C-shaped. The C-shape allows for the bushings 220 to be spread apart sufficiently to be inserted in grooves 222, but are resilient enough such that bushings 220 remain seated in grooves 222 once placed therein.
Bushings 220 serve to center and support wrench 112 as it is inserted in draw tube D. This aids the operator in using wrench 112, and bushings 220 also serve to help the operator locate socket 120 on jam nut 28. The bushings 220 are sized such that wrench 112 may be easily inserted and rotated within draw tube D, while still offering sufficient support to substantially center wrench 112 within the draw tube.
In use, when a reference stop is desired for a workpiece S, flange F of chuck C is removed, and sleeve 12 of reference stop 10 is inserted in opening O of chuck C. Flange 14 of stop 10 is then bolted to chuck C with bolts 20, and flange F replaced. The backstop 44 within sleeve 12 is then adjusted to the proper reference distance by turning threaded rod 22, using a ruler, scale, or other similar measuring device (not shown) which is inserted through opening O of chuck C and which contacts the reference stop. Threaded rod 22 is rotated by crank 110, which has first been inserted through wrench 112. Once backstop 44 is at the desired location as a reference for the workpiece, crank 110 is held stationary while wrench 112 is used to tighten jam nut 28 against end 30 of sleeve 12. This fixes rod 22 against further movement in or out of sleeve 12. Reference stop device 10 is then ready for use.
Removal of reference stop device 10 is accomplished in reverse order as was installation, except, that it is not necessary to use crank 110 and wrench 112 to remove reference stop 10 from lathe A, only flange 14 need be unbolted.
From the foregoing, it can be seen that the present invention provides a reference stop which can be easily inserted into a conventional lathe such as a computer numerical controlled ("CNC") lathe and which can be readily adjusted to provide a reference stop of desired depth for use of a tool T on a workpiece. Further, the present invention provides a combination tool which allows the backstop 44 within reference stop device 10 to be adjusted from outside of lathe A, without removing device 10 from lathe A.
Significantly, because reference stop device 10 is attached to chuck C, as jaws J of chuck C move radially inwardly during tightening against the workpiece S, the reference stop 10, and accordingly backstop 44 remains stationary with respect to jaws J. Therefore, the workpiece reference distance between backstop 44 and chuck C remains constant, even during tightening and loosening of chuck C. While preferred embodiments of the invention have been described using specific terms, such description is for present illustrative purposes only, and it is to be understood that changes and variations to such embodiments, including but not limited to the substitution of equivalent features or parts, and the reversal of various features thereof, may be practiced by those of ordinary skill in the art without departing from the spirit or scope of the present disclosure.
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A reference stop for use in a lathe having a movable chuck and a draw tube adjacent to the chuck. A movable backstop is provided for rectilinear movement within a sleeve. The sleeve is inserted through the chuck of the lathe and extends into the draw tube. A threaded rod is attached to the backstop and extends outwardly from the sleeve, into the draw tube, and in a direction away from the chuck. The threaded rod is turned by a wrench and driver combination, and turning of the threaded rod causes corresponding rectilinear movement of the backstop in the sleeve, thereby allowing for a workpiece reference stop which is adjustable with respect to the chuck.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. application Ser. No. 11/832,406, filed Aug. 1, 2007, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
Counterbatten systems are used with tile roof installations to elevate the roof tiles above the roof deck surface. By elevating the roof tiles, water is prevented from gathering under and/or around the roof tiles, which protects the roof deck from damage, and the air space created between the roof deck and the roof tiles facilitates ventilation of the roof.
Counterbatten systems are typically created by fastening wood strips, which are called vertical battens, in a vertical direction up the roof at 16″ or 24″ on center onto the roof decking. Horizontal, or anchor, battens are then fastened directly onto these vertical battens. The size of the batten strips will vary according to spacing and load factors, but the minimum dimensions are typically ⅜″ thick for the vertical strips and nominal 1″×3″ for the horizontal strips. By installing the horizontal battens onto the vertical battens, nail penetrations into the roof decking are minimized, and the nails that penetrate the roof deck are less likely to be exposed to water because they only penetrate the vertical strips that run parallel to water flow.
Although such counterbatten systems provide some advantages to tile roof installations, they may be time consuming to install. U.S. Pat. No. 6,536,171 discloses an elevated batten system solution in which pads or blocks are attached to the underside of the horizontal batten strips prior to installation, and these pads serve the function of the vertical strips of the counterbatten system. By not having to install the vertical strips, the installation may progress more quickly and with less materials. This elevated batten system uses diamond-shaped pads, which diverts the flow of any water to either side of the pad. Such systems require relatively accurate orientation and attachment of the pads relative to the strips, which can increase the amount of time and cost it takes to manufacture the batten strips. In addition, inconsistencies in the height of the batten strips at each pad may be introduced when the pads are attached to the horizontal strips if a fastener, such as a nail or staple, is not inserted into the pad properly or if varying amounts of adhesive are used to couple the pads to the horizontal strips.
Thus, there remains a need in the art for an improved elevated batten system.
SUMMARY OF THE INVENTION
Various embodiments of the invention provide a method for installing an improved elevated batten assembly for use atop an inclined roof supporting surface and for supporting tiles above the inclined roof supporting surface. The elevated batten assembly comprises (1) an elongate horizontal batten strip that has an underside for generally facing the inclined roof supporting surface and (2) a plurality of support pads that are spaced apart and coupled to the underside of the batten strip. The support pads each include opposing first and second sides, wherein each of the first and second sides comprises a substantially flat surface. The first side is coupled adjacent to and substantially in planar contact with the underside of the batten strip. In addition, the second side of each support pad is configured for being substantially in planar contact with the inclined roof supporting surface, the support pads support the batten strip above the inclined roof supporting surface, and each of the support pads have a cylindrical wall that extends between the first and second sides. According to one embodiment of the invention, the cylindrical-shaped pads do not require orientation relative to the horizontal batten, which may be required when using square or rectangular shaped pads. In addition, the cylindrical wall of the pads deflects water around the pads to prevent pooling, and the first and second sides of the pads allow the pads to fit substantially flush against the underside of the horizontal battens and the roof deck surface, which prevents debris and other materials from getting caught between the pads and the batten and/or the roof deck and prevents damming that can result in roof leaks or premature deterioration of the underlayment, battens, and/or fasteners.
According to other various embodiments of the invention, a method for installing an elevated batten assembly for use atop an inclined roof supporting surface and for supporting tiles above the inclined roof supporting surface is provided. The elevated batten assembly comprises (1) an elongate horizontal batten strip that has an underside for generally facing the inclined roof supporting surface and (2) a plurality of support pads that are spaced apart and coupled to the underside of the batten strip. The support pads each include opposing first and second substantially flat side portions, and the first substantially flat side portion of each support pad is coupled adjacent to and substantially in planar contact with the underside of said batten strip. The second substantially flat side portion of each support pad is configured for being substantially in planar contact with the inclined roof supporting surface. In addition, the support pads support the batten strip above the inclined roof supporting surface, and each of the second substantially flat side portions defines a depressed portion that is configured for receiving a fastener for coupling the support pad to the horizontal batten strip. According to one embodiment, installing the fastener in the depressed portion can prevent inconsistencies in the height of the horizontal batten along the length of the batten due to an improperly attached fastener.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of an elevated batten assembly 10 according to various embodiments of the invention.
FIG. 2A is a lower plan view of the elevated batten assembly 10 assembled according to a first configuration, according to various embodiments of the invention.
FIG. 2B is a lower plan view of the elevated batten assembly 10 assembled according to a second configuration, according to various embodiments of the invention.
FIG. 3 is schematic diagram of the flow of water 13 around an exemplary pad, according to various embodiments of the invention.
FIG. 4A is a lower plan view of a support pad having a depressed portion according to various embodiments of the invention.
FIG. 4B is a side elevational view of the support pad shown in FIG. 4A .
FIG. 5 is a pictorial view showing the outline of an exemplary group of tiles 100 installed atop the elevated batten assembly 10 according to various embodiments of the invention.
FIG. 6 shows two configurations of batten assemblies 10 a , 10 b stacked relative to each other such that the pads of the two batten assemblies have nest between each other in an alternating fashion, according to various embodiments of the invention.
FIG. 7A is a lower plan view of an assembled elevated batten assembly according to an alternative embodiment of the invention.
FIG. 7B is a perspective view of two of the assembled elevated batten assemblies shown in FIG. 7A stacked together according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The elevated batten system according to various embodiments of the present invention is designed to eliminate the need to install the vertical and horizontal battens in separate steps. In particular, pads 14 are attached to the underside of the horizontal battens 12 at the lumber mill or other assembly facility. These pads serve the function of spacing the horizontal batten strips above the roof deck surface, which was served by the the vertical strips used in the prior art counterbatten system described above, but the pads provide a more efficient method of installation and reduce the amount of materials used during installation.
According to various embodiments of the invention, the pads may be cylindrical-shaped or rectangular or square-shaped and made from wood (e.g., plywood) or another suitable material such as rubber, plastic (e.g., HDPE) or other polymer, and/or recycled materials. The pads are attached at pre-defined increments along horizontal batten strips with a suitable fastener (e.g., staples, adhesive, or nails) prior to bundling and shipping from the assembly facility. The pre-defined increments and the dimensions of the pads and the horizontal strips may depend on the load conditions and/or weather conditions to which the roof will be subject. The elevated batten system according to various aspects of the invention may then be installed horizontally along a roof such that the pads are disposed immediately adjacent the roof deck surface or underlayment. In addition, the pre-assembled elevated batten system can be used with any profile of roof tiles and in a variety of load conditions, according to various embodiments. Furthermore, in a particular embodiment, the battens may be treated with pressure treating or other weather resistant properties as needed.
In a particular embodiment, the pads 14 are cylindrical and have a diameter of about 1½″ and a thickness of about ⅜″. The pads are installed on one side of the horizontal batten 12 at 12″ intervals using a staple or other suitable fastener. The pads elevate the horizontal batten above the roof deck by a height substantially equal to the thickness of the pads 14 and provide adequate support for the horizontal batten 12 to prevent deflection.
Elevating the battens 12 allows for water and debris to pass freely beneath the battens and allows improved airflow above the roof support surface, which reduces heat gain in the roof system and reduces cooling costs. In addition, unlike rectangular or square-shaped pads, which may require orientation into a diamond-shape relative to the horizontal axis of the horizontal batten prior to attachment to the horizontal batten, cylindrical-shaped pads do not require orientation relative to the horizontal batten. Furthermore, the cylindrical walls of the pads deflect water around the pads to prevent pooling, and the flat sides of the pads allow the pads to fit substantially flush against the underside of the horizontal battens and the roof deck surface, which prevents debris and other materials from getting caught between the pads and the batten and/or the roof deck and prevents damming that can result in roof leaks or premature deterioration of the underlayment, battens, and/or fasteners. For example, as shown in FIG. 3 , water and/or debris 13 flow around the pad 14 .
In other various embodiments, the pads 14 have rectangular, square, or other polygonal shapes, have thicknesses greater than or less than ⅜″ depending on the height requirements of the installation, and may be installed at alternative selected intervals (e.g., 16 inches on center, 24 inches on center, or other selected distances).
According to a particular embodiment of the invention which is shown in FIGS. 2A and 2B , the pads 14 are spaced from the ends of the horizontal battens in at least two configurations. A first configuration 10 a is shown in FIG. 10A and a second configuration 10 b is shown in FIG. 10B . The pads 14 a in the first configuration 10 a are positioned closer to the end of the horizontal batten 12 a than the pads 14 b in the corresponding second configuration 10 b . The pads 14 b in the second configuration 10 b are spaced from the end of the horizontal batten 12 b such that a pair of battens 10 a , 10 b may be stacked with their respective pad sides cofacing, with the pads nesting between each other in an alternating fashion, such as shown in the embodiment in FIG. 6 . In addition, this alternating configuration provides for more efficient stacking and shipping and provides solid support at each end of adjoining battens. The batten assemblies 10 a, 10 b can be aligned and bundled with plastic strapping.
In an alternative embodiment, which is shown in FIGS. 7A and 7B , the pads are spaced from the ends of the battens to minimize the risk of splitting during the attachment to the roof. In a particular embodiment, the pads are positioned about three inches from each end of the batten, and when stacked, as shown in FIG. 7B , the ends of the battens are slightly staggered with respect to the each other.
The horizontal batten strips 12 are manufactured from wood, according to various embodiments of the invention. In a particular embodiment, the wood used for the strips 12 is Douglas Fir lumber, which is a strong, construction-grade material. Furthermore, the horizontal strips may be nominal about 1″×about 3″ or about 1″×about 2″ lumber and cut into about 4 foot or about 8 foot strips, according to various embodiments. The thickness of the lumber may be between about ⅜″ and about 1″ (e.g., about ¾″) and the height of the lumber may be between about 1″ and about 3″ (e.g., about 1½″ or about 2½″), according to various embodiments of the invention.
In addition, in a particular embodiment, twenty four 4 foot strips that are assembled with the support pads are bundled together and strapped, and each bundle provides a sufficient number of battens for installing approximately one square (100 square feet) of roofing tile. In another embodiment, twelve 8 foot strips assembled with support pads are bundled together and strapped, and each bundle provides a sufficient number of battens for installing approximately one square (100 square feet) of roofing tile. Furthermore, according to various embodiments, the strips 12 may be marked on the side of each strip 12 opposite the side to which the pads 14 are attached with to indicate nailing points, making installation easier for the roof system installers.
In other various embodiments such as those embodiments shown in FIGS. 1 , 4 A, and 4 B, the pads 14 comprise two substantially flat sides that are opposite each other. The first substantially flat side 16 a is installed adjacent the horizontal batten 12 , and the second substantially flat side 16 b is installed adjacent the roof deck surface.
In a particular embodiment which is shown in FIGS. 4A and 4B , a depressed portion 15 is further defined in at least one of the first and/or second substantially flat sides 16 a , 16 b . According to one embodiment, the depressed portion 15 is defined in the second substantially flat side 16 b and a fastener, such as a staple, nail, or screw, is engaged into the depressed portion 15 to attach the pad 14 to the horizontal batten 12 . The depth of the depressed portion 15 is dimensioned such that the head of the fastener when attached to the pad 14 and the horizontal batten 12 does not extend past the plane in which the substantially flat side 16 a , 16 b lies (e.g., the depth of the depressed portion 15 is at least as deep as the thickness of the head of the fastener and may further include some additional tolerance to provide for variations in manufacture of the fasteners, according to one embodiment), and the width of the depressed portion 15 is at least as wide as the width of the head of the fastener.
Installing the fastener in the depressed portion 15 prevents inconsistencies in the height of the horizontal batten 12 along the length of the batten 12 due to an improperly attached (e.g., protruding) fastener, for example. In addition, according to various embodiments such as the embodiment shown in FIG. 5 , the horizontal battens 12 are secured to the roof deck surface 200 using fasteners that are installed into the surface of the battens 12 opposite the underside to which the pads 14 are attached.
By installing the fasteners 20 through the batten 12 and the pad 14 , according to one embodiment, a hole in the roof deck surface 200 made by the fastener is protected from water and debris by the edges of the pads' 14 substantially flat sides 16 b . In addition, the depressed portion 15 allows for flush and non-flush type fasteners to be used to secure the pads 14 to the battens 12 . Upon installing the batten assemblies 10 to the roof deck surface 200 , tiles 100 may be installed over the batten in a conventional manner on the upwardly facing side of the battens.
CONCLUSION
Although this invention has been described in specific detail with reference to the disclosed embodiments, it will be understood that many variations and modifications may be effected within the spirit and scope of the invention as described in the appended claims.
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Various embodiments of the invention are directed to a method for installing an elevated batten system that includes a horizontal batten strip to which cylindrical-shaped pads are coupled. The pads elevate the horizontal batten strip above the roof deck surface, preventing water and debris from gathering on the roof deck surface and eliminating the need to install the vertical and horizontal battens in separate steps. Other various embodiments of the invention are directed to an elevated batten system that includes a horizontal batten strip to which pads are coupled that define a depressed portion. The depressed portion receives a fastener for coupling each pad to the horizontal batten strip, and in some embodiments, prevents irregularities in the height of the horizontal batten strip relative to the roof deck surface when installed on the roof deck surface.
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FIELD OF THE INVENTION
[0001] The present specification relates to a fluoranthene compound and an organic electronic device including the same.
BACKGROUND OF THE INVENTION
[0002] An organic electronic device means a device that needs charge exchanges between an electrode and an organic material using holes and/or electrons. An organic electronic device can be categorized into two main groups depending on the operation principle. First is an electric device in which excitons form in an organic material layer by the photons brought into the device from an external source, these excitons are separated into electrons and holes, and these electrons and holes are used as a current source (voltage source) by being transferred to different electrodes. Second is an electronic device in which holes and/or electrons are injected to an organic material semiconductor that forms an interface with an electrode by applying voltage or current to two or more electrodes, and the device is operated by the injected electrons and holes.
[0003] Examples of an organic electronic device include an organic light emitting device, an organic solar cell, an organic photo conductor (OPC), an organic transistor, and the like, and these all need a hole injection or transfer material, an electron injection or transfer material, or a light emitting material for the driving of the device. Hereinafter, an organic light emitting device will be described in detail, however, in the organic electronic devices, a hole injection or transfer material, an electron injection or transfer material, or a light emitting material is used under similar principles.
[0004] An organic light emission phenomenon generally refers to a phenomenon that converts electric energy to light energy using an organic material. An organic light emitting device using an organic light emission phenomenon typically has a structure that includes an anode, a cathode, and an organic material layer therebetween. Herein, the organic material layer is usually formed as a multilayer structure formed with different materials in order to improve the efficiency and the stability of an organic light emitting device, and for example, may be formed with a hole injection layer, a hole transfer layer, a light emitting layer, an electron transfer layer, an electron injection layer, and the like. In the structure of such an organic light emitting device, holes from an anode and electrons from a cathode flow into an organic material layer when voltage is applied between the two electrodes, excitons form when the electrons and the holes injected are combined, and light emits when these excitons fall back to the ground state. Such an organic light emitting device has been known to have characteristics such as spontaneous light emission, high brightness, high efficiency, low driving voltage, wide viewing angle, high contrast, and quick response.
[0005] In an organic light emitting device, the material used as an organic material layer can be divided into a light emitting material and a charge transfer material, for example, a hole injection material, a hole transfer material, an electron transfer material, an electron injection material and the like, depending on the function. In addition, the light emitting material can be divided into, depending on the light emitting color, a blue, a green and a red light emitting material, and a yellow and an orange light emitting material to obtain better natural color. Meanwhile, when only one material is used as the light emitting material, problems occur such as the maximum light emitting wavelength moving to a long wavelength due to the interaction between molecules, color purity being reduced, or the efficiency of the device being reduced due to a light emission diminution effect. Therefore, a host/dopant-based material may be used as the light emitting material in order to increase color purity and increase light emission efficiency through the energy transfer.
[0006] In order for an organic light emitting device to exhibit excellent characteristics described above, materials that form an organic material layer, for example, a hole injection material, a hole transfer material, a light emitting material, an electron transfer material, an electron injection material, and the like, need to be supported by stable and efficient materials first, however, the development of stable and efficient materials of an organic material layer for an organic light emitting device has not been sufficient so far. Therefore, there have been continuous demands for the development of new materials, and the needs for the development of such materials also apply to other organic electronic devices described above.
SUMMARY OF THE INVENTION
[0007] In view of the above, an objective of the present application is to provide a fluoranthene compound derivative having a chemical structure that can perform various roles required in an organic electronic device depending on substituents, and provide an organic electronic device including the fluoranthene compound derivative.
[0008] The present specification provides a fluoranthene compound represented by the following Chemical Formula 1.
[0000]
[0009] In Chemical Formula 1,
[0010] R1 to R3 are groups represented by -(L)p-(Y)q,
[0011] p is an integer of 0 to 10 and q is an integer of 1 to 10,
[0012] o is an integer of 1 to 5,
[0013] r is an integer of 0 to 6,
[0014] L is a substituted or unsubstituted arylene group; a substituted or unsubstituted alkenylene group; a substituted or unsubstituted fluorenylene group; or a substituted or unsubstituted heteroarylene group having O, N, S or P as a heteroatom,
[0015] Y is hydrogen; deuterium; a halogen group; a nitrile group; a nitro group; a hydroxy group; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted alkoxy group; a substituted or unsubstituted phosphine oxide group; a substituted or unsubstituted aryloxy group; a substituted or unsubstituted alkylthioxy group; a substituted or unsubstituted arylthioxy group; a substituted or unsubstituted alkylsulfoxy group; a substituted or unsubstituted arylsulfoxy group; a substituted or unsubstituted alkenyl group; a substituted or unsubstituted silyl group; a substituted or unsubstituted boron group; a substituted or unsubstituted amine group; a substituted or unsubstituted alkylamine group; a substituted or unsubstituted aralkylamine group; a substituted or unsubstituted arylamine group; a substituted or unsubstituted heteroarylamine group; a substituted or unsubstituted aryl group; a substituted or unsubstituted fluorenyl group; a substituted or unsubstituted carbazole group; or a substituted or unsubstituted heteroring group including one or more of N, O, S and P atoms,
[0016] when p≧2 or q≧2, Ls or Ys are the same as or different from each other,
[0017] R1 and R3 may be bonded to each other to form an aliphatic ring, an aromatic ring, an aliphatic heteroring or an aromatic heteroring, or form a spiro bond,
[0018] when o≧2, R4s are the same as or different from each other,
[0019] R4 is an aryl group substituted with a substituent selected from the group consisting of a substituted or unsubstituted heteroring group including a 5-membered ring or a 6-membered ring that includes one or more of O, S and P atoms, a substituted or unsubstituted monocyclic or multicyclic heteroring group including a 6-membered ring that includes one or more Ns, a substituted or unsubstituted benzocarbazole group, and a substituted or unsubstituted phosphine oxide group; a substituted or unsubstituted phosphine oxide group; a substituted or unsubstituted heteroring group including a 5-membered ring or a 6-membered ring that includes one or more of O, S and P atoms; a substituted or unsubstituted benzocarbazole group; or a substituted or unsubstituted monocyclic or multicyclic heteroring group including a 6-membered ring that includes one or more Ns, or adjacent groups among a plurality of R4s may form an aliphatic ring, an aromatic ring, an aliphatic heteroring or an aromatic heteroring, or form a spiro bond,
[0020] when r≧2, R5s are the same as or different from each other,
[0021] R5 is hydrogen; deuterium; a halogen group; a nitrile group; a nitro group; a hydroxy group; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted alkoxy group; a substituted or unsubstituted phosphine oxide group; a substituted or unsubstituted aryloxy group; a substituted or unsubstituted alkylthioxy group; a substituted or unsubstituted arylthioxy group; a substituted or unsubstituted alkylsulfoxy group; a substituted or unsubstituted arylsulfoxy group; a substituted or unsubstituted alkenyl group; a substituted or unsubstituted silyl group; a substituted or unsubstituted boron group; a substituted or unsubstituted amine group; a substituted or unsubstituted alkylamine group; a substituted or unsubstituted aralkylamine group; a substituted or unsubstituted arylamine group; a substituted or unsubstituted heteroarylamine group; a substituted or unsubstituted aryl group; a substituted or unsubstituted fluorenyl group; a substituted or unsubstituted carbazole group; or a substituted or unsubstituted heteroring group including one or more of N, O, S and P atoms, or adjacent groups among a plurality of R5s are bonded to each other to form an aliphatic ring, an aromatic ring, an aliphatic heteroring or an aromatic heteroring, or form a spiro bond.
[0022] In addition, the present specification provides an organic electronic device that includes a first electrode, a second electrode, and one or more layers of organic material layers disposed between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the fluoranthene compound of Chemical Formula 1.
Advantageous Effects
[0023] A fluoranthene derivative according to the present specification can be used as an organic material layer of an organic electronic device including an organic light emitting device, and the organic electronic device including the organic light emitting device using the fluoranthene derivative can have improved efficiency, low driving voltage and/or improved life span characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 shows an example of an organic electronic device formed with a substrate ( 1 ), an anode ( 2 ), a light emitting layer ( 3 ) and a cathode ( 4 ) by a diagram.
[0025] FIG. 2 shows an example of an organic electronic device formed with a substrate ( 1 ), an anode ( 2 ), a hole injection layer ( 5 ), a hole transfer layer ( 6 ), a light emitting layer ( 3 ), an electron transfer layer ( 7 ) and a cathode ( 4 ) by a diagram.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] The present specification provides a fluoranthene compound represented by Chemical Formula 1.
[0027] In addition, the compound represented by Chemical Formula 1 of the present specification may be represented by the following Chemical Formula 2.
[0000]
[0028] In Chemical Formula 2,
[0029] o, r, and R3 to R5 are the same as those defined in Chemical Formula 1,
[0030] each of n and m is an integer of 0 to 5,
[0031] when n≧2, R6s are the same as or different from each other,
[0032] when m≧2, R7s are the same as or different from each other,
[0033] R6 and R7 are the same as or different from each other, each independently hydrogen; deuterium; a halogen group; a nitrile group; a nitro group; a hydroxy group; a substituted or unsubstituted alkyl group; a substituted or unsubstituted cycloalkyl group; a substituted or unsubstituted alkoxy group; a substituted or unsubstituted phosphine oxide group; a substituted or unsubstituted aryloxy group; a substituted or unsubstituted alkylthioxy group; a substituted or unsubstituted arylthioxy group; a substituted or unsubstituted alkylsulfoxy group; a substituted or unsubstituted arylsulfoxy group; a substituted or unsubstituted alkenyl group; a substituted or unsubstituted silyl group; a substituted or unsubstituted boron group; a substituted or unsubstituted amine group; a substituted or unsubstituted alkylamine group; a substituted or unsubstituted aralkylamine group; a substituted or unsubstituted arylamine group; a substituted or unsubstituted heteroarylamine group; a substituted or unsubstituted aryl group; a substituted or unsubstituted fluorenyl group; a substituted or unsubstituted carbazole group; or a substituted or unsubstituted heteroring group including one or more of N, O, S and P atoms, or adjacent groups may be bonded to each other to form an aliphatic ring, an aromatic ring, an aliphatic heteroring or an aromatic heteroring, or form a spiro bond.
[0034] Examples of the substituents are described below, but are not limited thereto.
[0035] In addition, in the present specification, the term “substituted or unsubstituted” means being substituted with one or more substituents selected from the group consisting of deuterium; a halogen group; an alkyl group; an alkenyl group; an alkoxy group; a cycloalkyl group; a silyl group; an arylalkenyl group; an aryl group; an aryloxy group; an alkylthioxy group; an alkylsulfoxy group; an arylsulfoxy group; a boron group; an alkylamine group; an aralkylamine group; an arylamine group; a heteroaryl group; a carbazole group; an arylamine group; an aryl group; a fluorenyl group; a nitrile group; a nitro group; a hydroxy group; a cyano group, and a heteroring group including one or more of N, O, S and P atoms, or having no substituents.
[0036] In the present specification, an alkyl group may be linear or branched, and although not particularly limited, the number of carbon atoms is preferably 1 to 50. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a t-butyl group, a pentyl group, a hexyl group, a heptyl group and the like, but are not limited thereto.
[0037] In the present specification, the alkenyl group may be linear or branched, and although not particularly limited, the number of carbon atoms is preferably 2 to 50. Specific examples thereof preferably include an alkenyl group in which an aryl group such as a stilbenyl group or a styrenyl group is substituted, but are not limited thereto.
[0038] In the present specification, the alkoxy group may be linear or branched, and although not particularly limited, the number of carbon atoms is preferably 1 to 50.
[0039] The length of the alkyl group, the alkenyl group and the alkoxy group included in the compound does not have an influence on the conjugation length of the compound, and only concomitantly has an influence on the application method of the compound to an organic electronic device, for example, on the application of a vacuum deposition method or a solution coating method, therefore, the number of carbon atoms is not particularly limited.
[0040] In the present specification, the cycloalkyl group is not particularly limited, however, the number of carbon atoms is preferably 3 to 60, and particularly, a cyclopentyl group or a cyclohexyl group is preferable.
[0041] In the present specification, the aryl group may be monocyclic or multicyclic, and although not particularly limited, the number of carbon atoms is preferably 6 to 60. Specific examples of the aryl group include a monocyclic aromatic group such as a phenyl group, a biphenyl group, a triphenyl group, a terphenyl group or a stilbenyl group, and a multicyclic aromatic group such as a naphthyl group, a binaphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a perylenyl group, a tetracenyl group, a crycenyl group, a fluorenyl group, an acenaphthacenyl group, a triphenylene group or a fluoranthene group, but are not limited thereto.
[0042] In the present specification, the heteroring group is a heteroring group that includes O, N, S and P as a heteroatom, and although not particularly limited, the number of carbon atoms is preferably 2 to 60. Examples of the heteroring group include a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a bipyridyl group, a triazine group, an acridyl group, a pyridazine group, a qinolinyl group, an isoquinoline group, an indole group, a carbazole group, a benzoxazole group, a benzimidazole group, a benzothiazole group, a benzocarbazole group, a benzothiophene group, a dibenzothiophene group, a benzofuranyl group, a dibenzofuranyl group or the like, but are not limited thereto.
[0043] In the present specification, examples of the monocyclic or multicyclic heteroring group including a 6-membered ring that includes one or more Ns include a pyridine group, a pyrimidine group, a pyridazine group, a pyrazine group, a triazine group, a tetrazine group, a pentazine group, a quinoline group, a cynoline group, a quinazoline group, a quinoxaline group, a pyridopyrazine group, a pyrazinopyrazine group, a pyrazinoquinoxaline group, an acridine group, a phenanthroline group or the like, but are not limited thereto.
[0044] In the present specification, the monocyclic or multicyclic heteroring group including a 6-membered ring that includes one or more Ns is a heteroring group including at least one or more 6-membered rings that include one or more Ns, and also includes a heteroring group in which a 5-membered ring is fused to a 6-membered ring that includes one or more Ns. In other words, other 5-membered rings or 6-membered rings different from the specific examples described above may be additionally fused, and the fused 5-membered ring or 6-membered ring may be an aromatic ring, an aliphatic ring, an aliphatic heteroring and/or an aromatic heteroring.
[0045] In the present specification, examples of the halogen group include fluorine, chlorine, bromine or iodine.
[0046] In the present specification, the fluorenyl group has a structure in which two cyclic organic compounds are linked through one atom, and examples thereof include
[0000]
[0000] or the like.
[0047] In the present specification, the fluorenyl group includes the structure of an open fluorenyl group, and herein, the open fluorenyl group has a structure in which the linkage of one ring compound is broken in the structure of two ring compounds linked through one atom, and examples thereof include
[0000]
[0000] or the like.
[0048] In the present specification, the number of carbon atoms of the amine group is not particularly limited, but is preferably 1 to 50. Specific examples of the amine group include a methylamine group, a dimethylamine group, an ethylamine group, a diethylamine group, a phenylamine group, a naphthylamine group, a biphenylamine group, an anthracenylamine group, a 9-methyl-anthracenylamine group, a diphenylamine group, a phenylnaphthylamine group, a ditolylamine group, a phenyltolylamine group, a triphenylamine group or the like, but are not limited thereto.
[0049] In the present specification, the number of carbon atoms of the arylamine group is not particularly limited, but is preferably 6 to 50. Examples of the arylamine group include a substituted or unsubstituted monocyclic diarylamine group, a substituted or unsubstituted multicyclic diarylamine group or a substituted or unsubstituted monocyclic and monocyclic diarylamine group.
[0050] In the present specification, the number of carbon atoms of the aryloxy group, the arylthioxy group, the arylsulfoxy group and the aralkylamine group is not particularly limited, but is preferably 6 to 50. The aryl group in the aryloxy group, the arylthioxy group, the arylsulfoxy group and the aralkylamine group is the same as the examples of the aryl group described above.
[0051] In the present specification, the alkyl group in the alkylthioxy group, the alkylsulfoxy group, the alkylamine group and the aralkylamine group is the same as the examples of the alkyl group described above.
[0052] In the present specification, the heteroaryl group in a heteroarylamine group may be selected from among the examples of the heteroring group described above.
[0053] In the present specification, the arylene group, the alkenylene group, the fluorenylene group, and the heteroarylene group are divalent groups of the aryl group, the alkenyl group, the fluorenyl group, and the heteroaryl group, respectively. Descriptions for the aryl group, the alkenyl group, the fluorenyl group and the heteroaryl group may be applied to the arylene group, the alkenylene group, the fluorenylene group, and the heteroarylene group, except that these are divalent groups.
[0054] In the present specification, the substituted arylene group means that a phenyl group, a biphenyl group, a naphthyl group, a fluorenyl group, a pyrenyl group, a phenanthrenyl group, a perylene group, a tetracenyl group, an anthracenyl group, or the like, is substituted with other substituents.
[0055] In the present specification, the substituted heteroarylene group means that a pyridyl group, a thiophenyl group, a triazine group, a quinoline group, a phenanthroline group, an imidazole group, a thiazole group, an oxazole group, a carbazole group, and fused heteroring groups thereof such as a benzoquinoline group, a benzimidazole group, a benoxazole group, a benzothiazole group, a benzocarbazole group, a dibenzothiophenyl group, or the like, is substituted with other substituents.
[0056] An adjacent group in the present specification means each neighboring substituent when there are two or more substituents.
[0057] In the present specification, forming an aliphatic ring, an aromatic ring, an aliphatic heteroring or an aromatic heteroring with an adjacent group means that each of the adjacent substituents forms a bond to form a 5-membered to 7-membered multicyclic or monocyclic ring.
[0058] In the present specification, a spiro bond means a structure in which two cyclic organic compounds are linked to one atom, and may include a structure in which the linkage of one ring compound is broken in the structure of two cyclic organic compounds linked through one atom.
[0059] The present specification provides a novel fluoranthene compound represented by Chemical Formula 1. The compound may be used as an organic material layer in an organic electronic device due to its structural specificity.
[0060] In one embodiment of the present specification, R1 to R3 are represented by -(L)p-(Y)q.
[0061] In one embodiment of the present specification, p is an integer of 0 to 10.
[0062] In one embodiment of the present specification, p is 1.
[0063] In one embodiment of the present specification, p is 0.
[0064] In one embodiment of the present specification, q is an integer of 1 to 10.
[0065] In one embodiment of the present specification, q is 1.
[0066] In one embodiment of the present specification, L is a substituted or unsubstituted arylene group, a substituted or unsubstituted fluorenylene group, or a substituted or unsubstituted heteroarylene group.
[0067] In one embodiment of the present specification, L is a substituted or unsubstituted arylene group.
[0068] In one embodiment of the present specification, L is a substituted or unsubstituted phenylene group.
[0069] In one embodiment of the present specification, Y is hydrogen.
[0070] In one embodiment of the present specification, R4 is a substituted or unsubstituted benzoquinoline group; a substituted or unsubstituted phenanthroline group; a substituted or unsubstituted pyrimidine group; a substituted or unsubstituted triazine group; a substituted or unsubstituted benzophenanthridine group; a substituted or unsubstituted quinoline group; a substituted or unsubstituted carbazole group; a substituted or unsubstituted benzocarbazole group; a substituted or unsubstituted dibenzothiophene group; a substituted or unsubstituted dibenzofuran group; a substituted or unsubstituted phosphine oxide group; a substituted or unsubstituted benzothiophene group; or a substituted or unsubstituted benzofuran group; or a substituted or unsubstituted quinazoline group.
[0071] In one embodiment of the present specification, R4 forms an aliphatic ring by being bonded to an adjacent group.
[0072] In one embodiment of the present specification, R4 forms an aromatic ring by being bonded to an adjacent group.
[0073] In one embodiment of the present specification, R4 is a phenyl group substituted with at least one of the following substituents; or is at least one of the following substituents, or a plurality of adjacent R4s form a hydrocarbon ring substituted with at least one of the following substituents with each other.
[0000]
[0074] * means being linked to a hydrocarbon ring formed by Chemical Formula 1, a phenyl group or a plurality of adjacent R4s being bonded to each other,
[0075] The substituents may be unsubstituted or additionally substituted with substituents selected from the group consisting of a substituted or unsubstituted alkyl group; a substituted or unsubstituted aryl group; and a substituted or unsubstituted heteroring group including one or more of N, O, S and P atoms.
[0076] In one embodiment of the present specification, the substituents are additionally substituted with hydrogen; a methyl group; an ethyl group; a phenyl group; a naphthyl group; a biphenyl group; or a pyridine group.
[0077] In one embodiment of the present specification, the hydrocarbon ring may be an aromatic ring, an aliphatic ring, or a fused ring of an aliphatic ring and an aromatic ring, and may be monocyclic or multicyclic.
[0078] In the substituents, “being substituted” means that a hydrogen atom bonded to the carbon atom of a compound is replaced with other atoms or functional groups, and “substituent” includes all of hydrogen, other atoms and functional groups. The substitution position in the present specification is not limited as long as it is a position at which a hydrogen atom is substituted, that is, a position that can be substituted with substituents, and when two or more are substituted, the two or more substituents may be the same as or different from each other.
[0079] In one embodiment of the present specification, R4 is a substituted or unsubstituted benzoquinoline group.
[0080] In one embodiment of the present specification, R4 is a substituted or unsubstituted phenanthroline group.
[0081] In one embodiment of the present specification, R4 is a substituted or unsubstituted pyrimidine group.
[0082] In one embodiment of the present specification, R4 is a pyrimidine group substituted with a phenyl group.
[0083] In one embodiment of the present specification, R4 is a pyrimidine group substituted with a biphenyl group.
[0084] In one embodiment of the present specification, R4 is a substituted or unsubstituted triazine group.
[0085] In one embodiment of the present specification, R4 is a triazine group substituted with a phenyl group.
[0086] In one embodiment of the present specification, R4 is a triazine group substituted with a naphthyl group.
[0087] In one embodiment of the present specification, R4 is a substituted or unsubstituted benzophenanthridine group.
[0088] In one embodiment of the present specification, R4 is a substituted or unsubstituted quinoline group.
[0089] In one embodiment of the present specification, R4 is a quinoline group substituted with a phenyl group.
[0090] In one embodiment of the present specification, R4 is a quinoline group substituted with a pyridine group.
[0091] In one embodiment of the present specification, R4 is a substituent having a structure in which a phenanthridine group and a benzimidazole group are bonded.
[0092] In one embodiment of the present specification, R4 is a substituent having a structure in which a quinoline group and a benzimidazole group are bonded.
[0093] In one embodiment of the present specification, R4 is a substituted or unsubstituted benzocarbazole group. The benzocarbazole group is either
[0000]
[0094] In one embodiment of the present specification, R4 is a substituted or unsubstituted dibenzothiophene group. The dibenzothiophene group is linked to the fluoranthene core of the present compound at position 6 or position 2 of the following dibenzothiophene group structure.
[0000]
[0095] In one embodiment of the present specification, R4 is a substituted or unsubstituted dibenzofuran group. The dibenzofuran group is linked to the fluoranthene core of the present compound at position 6 or position 2 of the following dibenzofuran group structure.
[0000]
[0096] In one embodiment of the present specification, R4 is a substituted or unsubstituted phosphine oxide group.
[0097] In one embodiment of the present specification, R4 is a phosphine oxide group substituted with a phenyl group.
[0098] In one embodiment of the present specification, R4 is substituted or unsubstituted benzothiophene.
[0099] In one embodiment of the present specification, R4 is benzothiophene substituted with a phenyl group.
[0100] In one embodiment of the present specification, R4 is substituted or unsubstituted benzofuran.
[0101] In one embodiment of the present specification, R4 is benzofuran substituted with a phenyl group.
[0102] In one embodiment of the present specification, R4 is a substituted or unsubstituted quinazoline group.
[0103] In one embodiment of the present specification, R4 is a quinazoline group substituted with a phenyl group.
[0104] In one embodiment of the present specification, R4 is a substituted or unsubstituted phenanthrene group.
[0105] In one embodiment of the present specification, R4 is a substituted or unsubstituted a pyridine group.
[0106] In one embodiment of the present specification, R4 is a pyridine group substituted with a pyridine group.
[0107] Preferable specific examples of the compound according to the present specification include the following compounds, but are not limited thereto.
[0108] In one embodiment of the present specification, R4 is any one of the following structural formulae.
[0000]
[0109] In one embodiment of the present specification, R4 is any one of the following structural formulae.
[0000]
[0110] In one embodiment of the present specification, Chemical Formula 1 is represented by any one of the following Compounds 1 to 38.
[0000]
[0111] The compound of Chemical Formula 1 may have suitable characteristics for use as an organic material layer used in an organic electronic device by having fluoranthene as the core structure and introducing various substituents, as shown in Chemical Formula 1.
[0112] The conjugation length of a compound and the energy band gap have a close relationship. Specifically, the longer the conjugation length is, the smaller the energy band gap is. As described above, the compound core of Chemical Formula 1 includes limited conjugation, therefore, the energy band gap is large.
[0113] In the present specification, compounds having various energy band gap values may be synthesized by introducing various substituents at positions R1 to R7 and R′ of the core structure having a large energy band gap as above. Typically, adjusting an energy band gap by introducing substituents to a core structure having a large energy band gap is simple, however, when a core structure has a small energy band gap, largely adjusting the energy band gap is difficult by introducing substituents.
[0114] In addition, in the present specification, the HOMO and LUMO energy level of the compound may be adjusted by introducing various substituents at positions R1 to R7 and R′ of the core structure having the structure as above.
[0115] In addition, by introducing various substituents to the core structure having the structure as above, compounds having unique characteristics of the introduced substituents may be synthesized. For example, by introducing substituents normally used in a hole injection layer material, a hole transfer layer material, a light emitting layer material and an electron transfer layer material, which are used in the manufacture of an organic electronic device, to the core structure, materials satisfying the conditions required for each organic material layer may be synthesized.
[0116] The compound of Chemical Formula 1 includes fluoranthene in the core structure, thereby has an energy level suitable as a hole injection and/or a hole transfer material in an organic light emitting device. In the present specification, a device having low driving voltage and high light efficiency can be obtained by selecting compounds having suitable energy levels depending on the substituents among the compounds of Chemical Formula 1, and using the compound in an organic light emitting device.
[0117] In addition, by introducing various substituents to the core structure, the energy band gap can be finely adjusted, and meanwhile, characteristics at the interface between organic materials are improved, and therefore, the materials can have various applications.
[0118] Meanwhile, the compound of Chemical Formula 1 has excellent thermal stability due to its high glass transition temperature (T g ). This thermal stability enhancement becomes an important factor that provides a driving stability to a device.
[0119] The compound of Chemical Formula 1 may be prepared based on the preparation examples described later.
[0120] As the compound of Chemical Formula 1 of the present specification, a compound is synthesized by reacting acenaphthenequinone and substituted propanone. To this synthesized compound, ethynyl benzene to which a substituent is attached is synthesized, and the compound of Chemical Formula 1 is provided.
[0121] Alternatively, a compound is synthesized by reacting acenaphthenequinone and substituted propanone, a fluoranthene derivative is synthesized by reacting the compound with substituted ethynyl benzene, and then the compound of Chemical Formula 1 is provided by introducing various substituents to the fluoranthene derivative.
[0122] The present specification also provides an organic electronic device that uses the fluoranthene compound.
[0123] In one embodiment of the present specification, an organic electronic device provided includes a first electrode, a second electrode, and one or more layers of organic material layers provided between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the fluoranthene compound.
[0124] The organic electronic device may be selected from the group consisting of an organic light emitting device, an organic solar cell and an organic transistor.
[0125] The organic material layer of the organic electronic device of the present specification may be formed as a monolayer structure, but may be formed as a multilayer structure in which two or more layers of the organic material layers are laminated. For example, the organic light emitting device of the present specification may have a structure including a hole injection layer, a hole transfer layer, a light emitting layer, an electron transfer layer, an electron injection layer, and the like as the organic material layer. However, the structure of the organic light emitting device is not limited thereto, and may include less number of organic material layers.
[0126] In another embodiment, the organic electronic device may be a normal-type organic electronic device in which an anode, one or more layers of organic material layers, and a cathode are laminated on a substrate in consecutive order.
[0127] In another embodiment, the organic electronic device may be an inverted-type organic electronic device in which a cathode, one or more layers of organic material layers, and an anode are laminated on a substrate in consecutive order.
[0128] The organic electronic device of the present specification may be prepared using materials and methods known in the related art except that the compound of the present specification, that is, the fluoranthene compound, is included in one or more layers of organic material layers.
[0129] For example, the organic electronic device of the present specification may be manufactured by laminating a first electrode, an organic material layer and a second electrode on a substrate in consecutive order. At this time, the organic electronic device may be manufactured by forming an anode through the deposition of a metal, a metal oxide having conductivity, or alloys thereof on a substrate using a physical vapor deposition (PVD) method such as a sputtering method or an e-beam evaporation method, forming an organic material layer that includes a hole injection layer, a hole transfer layer, a light emitting layer and an electron transfer layer thereon, and then depositing a material that can be used as a cathode thereon. In addition to this method, the organic electronic device may be manufactured by consecutively depositing a cathode material, an organic material layer and an anode material on a substrate.
[0130] In addition, when the organic electronic device is manufactured, the fluoranthene compound may be formed as an organic material layer using a solution coating method as well as a vacuum deposition method. Herein, the solution coating method means spin coating, dip coating, doctor blading, ink jet printing, screen printing, a spray method, roll coating or the like, but is not limited thereto.
[0131] In one embodiment of the present specification, the organic electronic device may be an organic light emitting device.
[0132] In one embodiment of the present specification, an organic light emitting device provided includes a first electrode, a second electrode, and one or more layers of organic material layers including a light emitting layer provided between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the fluoranthene compound.
[0133] In one embodiment of the present specification, the organic material layer includes a hole injection layer, a hole transfer layer, or a layer that injects and transfers holes at the same time, and the hole injection layer, the hole transfer layer, or the layer that injects and transfers the holes at the same time includes the fluoranthene compound.
[0134] In one embodiment of the present specification, the organic material layer includes an electron transfer layer, an electron injection layer, or a layer that transfers and injects electrons at the same time, and the electron transfer layer, the electron injection layer, or the layer that transfers and injects electrons at the same time includes the fluoranthene compound.
[0135] In one embodiment of the present specification, the light emitting layer includes the fluoranthene compound.
[0136] In one embodiment of the present specification, the light emitting layer includes the fluoranthene compound as the host of the light emitting layer.
[0137] In one embodiment of the present specification, the light emitting layer includes the fluoranthene compound as the host of the light emitting layer, and a dopant may be selected from among dopant materials known in the industry by those skilled in the related art depending on the characteristics required in an organic light emitting device, but is not limited thereto.
[0138] In one embodiment of the present specification, the organic light emitting device further includes one, two or more layers selected from the group consisting of a hole injection layer, a hole transfer layer, an electron transfer layer, an electron injection layer, an electron blocking layer and a hole blocking layer.
[0139] In another embodiment, the organic material layer of the organic light emitting device may include a hole injection layer or a hole transfer layer including a compound that includes an arylamino group, a carbazole group or a benzocarbazole group, in addition to an organic material layer that includes the fluoranthene compound represented by Chemical Formula 1.
[0140] In one embodiment of the present specification, the organic light emitting device may be a top-emission type, a bottom-emission type or a dual-emission type depending on the materials used.
[0141] For example, in embodiments of the organic electronic device of the present specification, the organic electronic device may have a structure shown in FIG. 1 and FIG. 2 , but the structure is not limited thereto.
[0142] FIG. 1 illustrates the structure of an organic electronic device in which a substrate ( 1 ), an anode ( 2 ), a light emitting layer ( 3 ) and a cathode ( 4 ) are laminated in consecutive order. In this structure, the fluoranthene compound may be included in the light emitting layer ( 3 ).
[0143] FIG. 2 illustrates the structure of an organic electronic device in which a substrate ( 1 ), an anode ( 2 ), a hole injection layer ( 5 ), a hole transfer layer ( 6 ), a light emitting layer ( 3 ), an electron transfer layer ( 7 ) and a cathode ( 4 ) are laminated in consecutive order. In this structure, the fluoranthene compound may be included in one or more layers of the hole injection layer ( 5 ), the hole transfer layer ( 6 ), the light emitting layer ( 3 ) and the electron transfer layer ( 7 ).
[0144] In one embodiment of the present specification, the organic electronic device may be an organic solar cell.
[0145] In one embodiment of the present specification, an organic solar cell provided includes a first electrode; a second electrode; and one or more layers of organic material layers including a photoactive layer provided between the first electrode and the second electrode, wherein one or more layers of the organic material layers include the fluoranthene compound.
[0146] In one embodiment of the present specification, the organic material layer includes an electron transfer layer, an electron injection layer, or a layer that transfers and injects electrons at the same time, and the electron transfer layer, the electron injection layer, or the layer that transfers and injects electrons at the same time includes the fluoranthene compound.
[0147] In another embodiment, the photoactive layer may include the fluoranthene compound.
[0148] In another embodiment, the organic material layer includes an electron donor and an electron acceptor, and the electron donor or the electron acceptor includes the fluoranthene compound.
[0149] In one embodiment of the present specification, when the organic solar cell receives photons from an external light source, electrons and holes are generated between the electron donor and the electron acceptor. The generated holes are transferred to an anode through an electron donor layer.
[0150] In one embodiment of the present specification, the organic solar cell may further include additional organic material layers. The organic solar cell may reduce the number of organic material layers by using organic materials simultaneously having a number of functions.
[0151] In one embodiment of the present specification, the organic electronic device may be an organic transistor.
[0152] In one embodiment of the present specification, an organic transistor provided includes a source, a drain, a gate and one or more layers of organic material layers, wherein one or more layers of the organic material layers include the fluoranthene compound.
[0153] In one embodiment of the present specification, the organic transistor may include a charge generation layer, and the charge generation layer may include the fluoranthene compound.
[0154] In another embodiment, the organic transistor may include an insulation layer, and the insulation layer may be located on the substrate and the gate.
[0155] When the organic electronic device includes a plurality of organic material layers, the organic material layers may be formed with identical materials or different materials.
[0156] In one embodiment of the present specification, the first electrode is a cathode, and the second electrode is an anode.
[0157] In one embodiment of the present specification, the first electrode is an anode, and the second electrode is a cathode.
[0158] The substrate may be selected considering optical properties and physical properties as necessary. For example, the substrate is preferably transparent. Hard materials may be used as the substrate, however, the substrate may be formed with flexible materials such as plastic.
[0159] Materials of the substrate include, in addition to glass and quartz, polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polypropylene (PP), polyimide (PI), polycarbonate (PC), polystyrene (PS), polyoxymethylene (POM), an acrylonitrile styrene (AS) copolymer, an acrylonitrile butadiene styrene (ABS) copolymer, triacetyl cellulose (TAC), polyarylate (PAR), and the like, but are not limited thereto.
[0160] As the cathode material, a material having small work function is normally preferable so that electron injection to the organic material layer is smooth. Specific examples of the cathode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or alloys thereof; multilayer structure materials such as LiF/Al or LiO 2 /Al, or the like, but are not limited thereto.
[0161] As the anode material, a material having large work function is normally preferable so that hole injection to the organic material layer is smooth. Specific examples of the anode material that can be used in the present specification include metals such as vanadium, chromium, copper, zinc or gold, or alloys thereof; metal oxides such as zinc oxides, indium oxides, indium tin oxides (ITO) or indium zinc oxides (IZO); and mixtures of metals and oxides such as ZnO:Al or SnO 2 :Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole and polyaniline, or the like, but are not limited thereto.
[0162] The hole transfer layer is a layer that receives holes from a hole injection layer and transfers the holes to a light emitting layer, and a hole transfer material is a material that can receive holes from an anode or a hole injection layer, move the holes to a light emitting layer, and a material having high mobility for holes is suitable. Specific examples thereof include an arylamine-based organic material, a conductive polymer, a block copolymer having conjugated parts and non-conjugated parts together, and the like, but are not limited thereto.
[0163] The hole injection layer is a layer that injects holes from an electrode, and a hole injection material is preferably a compound that has an ability to transfer the holes thereby has a hole injection effect in an anode and has an excellent hole injection effect for a light emitting layer or a light emitting material, prevents the movement of excitons generated in the light emitting layer to an electron injection layer or an electron injection material, and in addition, has excellent thin film forming ability. The highest occupied molecular orbital (HOMO) of the hole injection material is preferably between the work function of an anode and the HOMO of surrounding organic material layers. Specific examples of the hole injection material include a metal porphyrin, oligothiophene, an arylamine-based organic material, a phthalocyanine derivative, a hexanitrile hexazatriphenylene-based organic material, a quinacridone-based organic material, a perylene-based organic material, anthraquinone, and a polyaniline- and polythiophene-based conductive polymer, and the like, but are not limited thereto.
[0164] The light emitting material is a material that can emit light in a visible light region by receiving holes and electrons from a hole transfer layer and an electron transfer layer, respectively, and binding the holes and the electrons, and is preferably a material having favorable quantum efficiency for fluorescence or phosphorescence. Specific examples thereof include a 8-hydroxy-quinoline aluminum complex (Alq 3 ); a carbazole-based compound; a dimerized styryl compound; BAlq; a 10-hydroxybenzo quinoline-metal compound; a benzoxazole-, a benzthiazole- and a benzimidazole-based compound; a poly(p-phenylenevinylene) (PPV)-based polymer; a spiro compound; polyfluorene, rubrene or the like, but are not limited thereto.
[0165] The light emitting layer may include a host material and a dopant material. The host material includes a fused aromatic ring derivative, a heteroring-containing compound, or the like. Specifically, the fused aromatic ring derivative includes an anthracene derivative, a pyrene derivative, a naphthalene derivative, a pentacene derivative, a phenanthrene compound, a fluoranthene compound or the like, and the heteroring-containing compound includes a carbazole derivative, a dibenzofuran derivative, a ladder-type furan compound, a pyrimidine derivative or the like, but are not limited thereto.
[0166] The dopant material includes organic compounds, metals or metal compounds.
[0167] The dopant material includes an aromatic amine derivative, a styrylamine compound, a boron complex, a fluoranthene compound, a metal complex, or the like. Specifically, the aromatic amine derivative includes arylamino-including pyrene, anthracene, crycene and periflanthene as the fused aromatic ring derivative having a substituted or unsubstituted arylamino group, and the styrylamine compound includes a compound in which substituted or unsubstituted arylamine is substituted with at least one arylvinyl group, and one, two or more substituents selected from the group consisting of an aryl group, a silyl group, an alkyl group, a cycloalkyl group and an arylamino group are substituted or unsubstituted. Specifically, styrylamine, styryldiamine, styryltriamine, styryltetramine or the like is included, but the styrylamine compound is not limited thereto. In addition, the metal complex includes an iridium complex, a platinum complex or the like, but is not limited thereto.
[0168] The electron transfer layer is a layer that receives electrons from an electron injection layer and transfers the electrons to a light emitting layer, and an electron transfer material is a material that can receive electrons from a cathode, move the electrons to a light emitting layer, and a material having high mobility for electrons is suitable. Specific examples thereof include an Al complex of 8-hydroxyquinoline; a complex including Alq3; an organic radical compound; a hydroxyflavone-metal complex or the like, but are not limited thereto. The electron transfer layer can be used together with any desired cathode material as is used according to technologies in the related art. Particularly, examples of the suitable cathode material are common materials that have small work function, and followed by an aluminum layer or a silver layer. Specifically the cathode material includes cesium, barium, calcium, ytterbium and samarium, and in each case, an aluminum layer or a silver layer follows.
[0169] The electron injection layer is a layer that injects electrons from an electrode, and an electron injection material is preferably a compound that has an ability to transfer the electrons, has an electron injection effect in a cathode and has an excellent electron injection effect for a light emitting layer or a light emitting material, prevents the movement of excitons generated in the light emitting layer to the electron injection layer, and in addition, has excellent thin film forming ability. Specific examples thereof include fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylene tetracarboxylic acid, fluorenylidene methane, anthrone or the like, and derivatives thereof, a metal complex compound, a nitrogen-containing 5-membered ring derivative, or the like, but are not limited thereto.
[0170] The metal complex compound includes 8-hydroxyquinolinato lithium, bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper, bis(8-hydroxyquinolinato)manganese, tris(8-hydroxyquinolinato)aluminum, tris(2-methyl-8-hydroxyquinolinato)aluminum, tris(8-hydroxyquinolinato)gallium, bis(10-hydroxybenzo[h]quinolinato)berylium, bis(10-hydroxybenzo[h]quinolinato)zinc, bis(2-methyl-8-quinolinato)chlorogallium, bis(2-methyl-8-quinolinato)(o-cresolato)gallium, bis(2-methyl-8-quinolinato)(1-naphtholato)aluminum, bis(2-methyl-8-quinolinato)(2-naphtholato)gallium or the like, but is not limited thereto.
[0171] The hole blocking layer is a layer that blocks the arrival of holes in a cathode, and generally, may be formed under the same conditions as those of the hole injection layer. Specific examples thereof include an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, BCP, an aluminum complex or the like, but are not limited thereto.
[0172] The electron blocking layer is a layer that improves the probability of electron-hole recombination by receiving holes while blocking electrons, and a material having significantly low electron transfer ability while having hole transfer ability are suitable. As the material of the electron blocking layer, the materials of the hole transfer layer described above may be used as necessary, but the material is not limited thereto, and known electron blocking layers may be used.
[0173] The organic electronic device according to the present specification may be a top-emission type, a bottom-emission type or a dual-emission type depending on the materials used.
[0174] Hereinafter, a method for preparing the compound represented of Chemical Formula 1 and the manufacture of an organic light emitting device including the same will be described in detail with reference to examples. However, the following examples are for illustrative purposes only, and the scope of the present specification is not limited thereto.
Preparation Example
(1) Preparation of [Compound A-1]
[0175]
[0176] After acenaphthenequinone (30 g, 164 mmol) and 1,3-diphenyl-2-propanone (34 g, 164 mmol) were placed in ethanol (600 mL), potassium hydroxide (KOH) (27.6 g, 492 mmol) was added thereto, and the mixture was stirred under reflux for hours at 85° C. The temperature was lowered to room temperature, 300 mL of water was added thereto, the solid produced was filtered and dried, and [Compound A-1] (45 g, yield 77%) was prepared. MS: [M+H] + =357
(2) Preparation of [Compound A-2]
[0177]
[0178] After [Compound A-1] (30 g, 84.2 mmol) and 1-bromo-4-ethynylbenzene (16.8 g, 92.8 mmol) were placed in xylene (500 mL), the mixture was stirred under reflux for 48 hours at 140° C. The temperature was lowered to room temperature, 300 mL of ethanol was added thereto, the solid produced was filtered and dried, and [Compound A-2] (31.3 g, yield 74%) was prepared. MS: [M+H] + =510
(3) Preparation of [Compound A-3]
[0179]
[0180] After [Compound A-1] (30 g, 84.2 mmol) and 1-bromo-4-ethynylbenzene (16.8 g, 92.8 mmol) were placed in xylene (500 mL), the mixture was stirred under reflux for 48 hours at 140° C. The temperature was lowered to room temperature, 300 mL of ethanol was added thereto, the solid produced was filtered and dried, and [Compound A-2] (29.7 g, yield 69%) was prepared. MS: [M+H] + =510
(4) Preparation of [Compound B-1]
[0181]
[0182] After acenaphthenequinone (6.9 g, 38 mmol) and 1,3-bis(4-bromophenyl)propan-2-one (14 g, 38 mmol) were placed in ethanol (300 mL), potassium hydroxide (KOH) (6.4 g, 114 mmol) was added thereto, and the mixture was stirred under reflux for 48 hours at 85° C. The temperature was lowered to room temperature, 200 mL of water was added thereto, the solid produced was filtered and dried, and [Compound B-1] (17.3 g, yield 88%) was prepared. MS: [M+H] + =515
(5) Preparation of [Compound B-2]
[0183]
[0184] After [Compound B-1] (17.3 g, 33.6 mmol) and ethynylbenzene (4.1 g, 40.3 mmol) were placed in xylene (200 mL), the mixture was stirred under reflux for 48 hours at 140° C. The temperature was lowered to room temperature, 200 mL of ethanol was added thereto, the solid produced was filtered and dried, and [Compound B-2] (14.3 g, yield 72%) was prepared. MS: [M+H] + =589
(6) Preparation of [Compound C-1]
[0185]
[0186] After [Compound A-2] (30 g, 58.9 mmol) and bis(pinacolato)diboron (16.5 g, 64.8 mmol) were placed in dioxane (300 mL), potassium acetate (17.3 g, 177 mmol) and then Pd(dppf)Cl 2 CH 2 Cl 2 (0.96 g, 2 mol %) were added thereto, and the mixture was stirred under reflux for 6 hours. The temperature was lowered to room temperature, and the result was filtered. After the filtrate was vacuum distilled and dissolved in chloroform, the result was recrystallized using ethanol, filtered and dried, and [Compound C-1] (27.2 g, yield 83%) was prepared. MS: [M+H] + =557
(7) Preparation of [Compound C-2]
[0187]
[0188] After [Compound A-3] (30 g, 58.9 mmol) and bis(pinacolato)diboron (16.5 g, 64.8 mmol) were placed in dioxane (300 mL), potassium acetate (17.3 g, 177 mmol) and then Pd(dppf)Cl 2 CH 2 Cl 2 (0.96 g, 2 mol %) were added thereto, and the mixture was stirred under reflux for 6 hours. The temperature was lowered to room temperature, and the result was filtered. After the filtrate was vacuum distilled and dissolved in chloroform, the result was recrystallized using ethanol, filtered and dried, and [Compound C-2] (26.2 g, yield 80%) was prepared. MS: [M+H] + =557
EXAMPLE
Example 1
Preparation of [Compound 2]
[0189]
[0190] After [Compound C-1] (17.6 g, 31.6 mmol) and 2-bromo-1,10-phenanthroline (8.2 g, 31.6 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 2] (16.5 g, yield 86%) was prepared. MS: [M+H] + =609
Example 2
Preparation of [Compound 6]
[0191]
[0192] After [Compound C-1] (17.6 g, 31.6 mmol) and 2-chloro-4,6-diphenylpyrimidine (8.4 g, 31.6 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 6] (15.6 g, yield 75%) was prepared. MS: [M+H] + =661
Example 3
Preparation of [Compound 7]
[0193]
[0194] After [Compound C-1] (17.6 g, 31.6 mmol) and 4-chloro-2,6-diphenylpyrimidine (8.4 g, 31.6 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 7] (14.6 g, yield 70%) was prepared. MS: [M+H] + =661
Example 4
Preparation of [Compound 8]
[0195]
[0196] After [Compound C-1] (17.6 g, 31.6 mmol) and 2-chloro-4,6-diphenyl-1,3,5-triazine (8.4 g, 31.6 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 8] (16.1 g, yield 77%) was prepared. MS: [M+H] + =662
Example 5
Preparation of [Compound 26]
[0197]
[0198] After [Compound A-2] (15 g, 29.4 mmol) and 4-dibenzothiophene boronic acid (6.7 g, 29.4 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 26] (12.6 g, yield 70%) was prepared. MS: [M+H] + =613
Example 6
Preparation of [Compound 27]
[0199]
[0200] After [Compound A-2] (15 g, 29.4 mmol) and 4-dibenzofuran boronic acid (6.2 g, 29.4 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 27] (13.5 g, yield 77%) was prepared. MS: [M+H] + =597
Example 7
Preparation of [Compound 11]
[0201]
[0202] After [Compound C-2] (15 g, 26.8 mmol) and 2-chloro-4,6-diphenyl-1,3,5-triazine (7.16 g, 26.8 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.67 g, mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 11] (13.3 g, yield 75%) was prepared. MS: [M+H] + =661
Example 8
Preparation of [Compound 24]
[0203]
[0204] After [Compound A-2] (15 g, 29.5 mmol) and 11H-benzo[a]carbazole (6.4 g, 29.5 mmol) were placed in toluene (150 mL), sodium tetrabutoxide (NaOtBu) (15 g) and then Pd(PtBu 4 ) 2 (0.16 g, 1 mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 24] (11.4 g, yield 60%) was prepared. MS: [M+H] + =645
Example 9
Preparation of [Compound 32]
[0205]
[0206] After [Compound C-1] (18.0 g, 32.4 mmol) and (4-bromophenyl)diphenylphosphineoxide (11.6 g, 32.4 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and then Pd(PPh 3 ) 4 (0.75 g, 2 mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 32] (13.7 g, yield 64%) was prepared. MS: [M+H] + =706
Example 10
Preparation of [Compound 38]
[0207]
[0208] After [Compound C-1] (15.0 g, 27.0 mmol) and 4′-(4-bromophenyl)-2,2′:6′,2″-terpyridine (10.5 g, 27.0 mmol) were placed in tetrahydrofuran (THF) (200 mL), a 2M aqueous potassium carbonate (K 2 CO 3 ) solution (100 mL) and Pd(PPh 3 ) 4 (0.62 g, 2 mol %) were added thereto, and the mixture was stirred under reflux for 4 hours. The temperature was lowered to room temperature, and the solid produced was filtered. The filtered solid was recrystallized using chloroform and ethanol, then filtered and dried, and [Compound 38] (15.5 g, yield 78%) was prepared. MS: [M+H] + =737
EXPERIMENTAL EXAMPLE
Manufacture of Organic Light Emitting Device and Characteristics Measurements Thereof
Experimental Example 1-1
[0209] A glass substrate on which indium tin oxide (ITO) was coated as a thin film to a thickness of 500 Å was placed in distilled water in which a detergent is dissolved, and then was ultrasonic cleaned. At this time, a product of Fischer Corporation was used as the detergent, and as the distilled water, distilled water filtered twice with a filter manufactured by Millipore Corporation was used. After the ITO was cleaned for 30 minutes, ultrasonic cleaning was repeated twice for 10 minutes using distilled water. After the cleaning with distilled water was finished, ultrasonic cleaning was performed using an isopropyl alcohol, acetone and methanol solvent, and the substrate was dried and transferred to a plasma washer. In addition, the substrate was washed for 5 minutes using oxygen plasma, and transferred to a vacuum deposition apparatus.
[0210] On the transparent ITO electrode prepared as above, a hole injection layer was formed to a thickness of 100 Å by thermal vacuum depositing hexanitrile hexazatriphenylene (HAT) of the following chemical formula.
[0000]
[0211] On the hole injection layer, a hole transfer layer was formed by vacuum depositing 4-4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) (1,000 Å) of the chemical formula above.
[0212] Subsequently, a light emitting layer was formed on the hole transfer layer to a film thickness of 230 Å by vacuum depositing the following GH and GD in the weight ratio of 10:1.
[0000]
[0213] On the light emitting layer, an electron injection and transfer layer was formed to a film thickness of 350 Å by vacuum depositing [Compound 2].
[0214] A cathode was formed on the electron injection and transfer layer by depositing lithium fluoride (LiF) to a thickness of 15 Å and aluminum to a thickness of 2,000 Å in consecutive order.
[0215] In the above process, the deposition rate of the organic material was maintained to be 0.4 to 0.7 Å/sec, the deposition rate of the lithium fluoride of the cathode to be 0.3 Å/sec, and the deposition rate of the aluminum to be 2 Å/sec, and the degree of vacuum when being deposited was maintained to be 2×10 −7 to 5×10 −8 torr, and as a result, the organic light emitting device was manufactured.
Experimental Example 1-2
[0216] The organic light emitting device was manufactured using the same method as in Experimental Example 1-1 except that [Compound 8] was used instead of [Compound 2] in Experimental Example 1-1.
Experimental Example 1-3
[0217] The organic light emitting device was manufactured using the same method as in Experimental Example 1-1 except that [Compound 11] was used instead of [Compound 2] in Experimental Example 1-1.
Experimental Example 1-4
[0218] The organic light emitting device was manufactured using the same method as in Experimental Example 1-1 except that [Compound 32] was used instead of [Compound 2] in Experimental Example 1-1.
Experimental Example 1-5
[0219] The organic light emitting device was manufactured using the same method as in Experimental Example 1-1 except that [Compound 38] was used instead of [Compound 2] in Experimental Example 1-1.
Comparative Example 1
[0220] The organic light emitting device was manufactured using the same method as in Experimental Example 1-1 except that the compound of the following Chemical Formula ET-B was used instead of [Compound 2] in Experimental Example 1-1.
[0000]
[0221] When current (10 mA/cm 2 ) was applied to the organic light emitting device manufactured by Experimental Example 1-1 to Experimental Example 1-5, and Comparative Example 1, the results of Table 1 were obtained.
[0000]
TABLE 1
Color
Voltage
Efficiency
Coordinates
Compound
(V)
(cd/A)
(x, y)
Experimental
2
3.71
41.25
(0.374,
Example 1-1
0.621)
Experimental
8
4.15
39.11
(0.374,
Example 1-2
0.621)
Experimental
11
4.10
40.20
(0.374,
Example 1-3
0.620)
Experimental
32
4.50
37.25
(0.373,
Example 1-4
0.618)
Experimental
38
3.63
43.55
(0.373,
Example 1-5
0.618)
Comparative
ET-B
5.51
25.53
(0.373,
Example 1
0.617)
Experimental Example 2-1
[0222] On the transparent ITO electrode prepared as in Experimental Example 1-1, a hole injection layer was formed to a thickness of 100 Å by thermal vacuum depositing hexanitrile hexazatriphenylene (HAT) of the chemical formula above.
[0223] On the hole injection layer, a hole transfer layer was formed by vacuum depositing 4-4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) (700 Å), hexanitrile hexazatriphenylene (HAT) (50 Å) and 4-4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) (700 Å) of the chemical formula above in consecutive order.
[0224] Subsequently, a light emitting layer was formed on the hole transfer layer to a film thickness of 200 Å by vacuum depositing the following BH and BD in the weight ratio of 25:1.
[0000]
[0225] On the light emitting layer, an electron injection and transfer layer was formed to a thickness of 300 Å by vacuum depositing [Compound 7] and the lithium quinolate (LiQ) of the following chemical formula in the weight ratio of 1:1.
[0000]
[0226] A cathode was formed on the electron injection and transfer layer by depositing lithium fluoride (LiF) to a thickness of 15 Å and aluminum to a thickness of 2,000 Å in consecutive order.
[0227] In the above process, the deposition rate of the organic material was maintained to be 0.4 to 0.7 Å/sec, the deposition rate of the lithium fluoride of the cathode to be 0.3 Å/sec, and the deposition rate of the aluminum to be 2 A/sec, and the degree of vacuum when being deposited was maintained to be 2×10 −7 to 5×10 −8 torr, and as a result, the organic light emitting device was manufactured.
Experimental Example 2-2
[0228] The organic light emitting device was manufactured using the same method as in Experimental Example 2-1 except that [Compound 2] was used instead of [Compound 7] in Experimental Example 2-1.
Experimental Example 2-3
[0229] The organic light emitting device was manufactured using the same method as in Experimental Example 2-1 except that [Compound 27] was used instead of [Compound 7] in Experimental Example 2-1.
Experimental Example 2-4
[0230] The organic light emitting device was manufactured using the same method as in Experimental Example 2-1 except that [Compound 38] was used instead of [Compound 7] in Experimental Example 2-1.
Comparative Example 2
[0231] The organic light emitting device was manufactured using the same method as in Experimental Example 2-1 except that the compound of the following Chemical Formula ET-C was used instead of [Compound 7] in Experimental Example 2-1.
[0000]
[0232] When current (10 mA/cm 2 ) was applied to the organic light emitting device manufactured by Experimental Examples 2-1 to 2-4 and Comparative Example 2, the results of Table 2 were obtained.
[0000]
TABLE 2
Color
Voltage
Efficiency
Coordinates
Compound
(V)
(cd/A)
(x, y)
Experimental
7
4.35
6.43
(0.133,
Example 2-1
0.154)
Experimental
2
4.10
6.33
(0.133,
Example 2-2
0.153)
Experimental
27
4.51
5.99
(0.133,
Example 2-3
0.153)
Experimental
38
4.22
6.25
(0.134,
Example 2-4
0.154)
Comparative
ET-C
5.21
5.51
(0.134,
Example 2
0.153)
[0233] From the results of Table 2, it can be seen that the novel compound according to the present specification can be used as the material of an organic material layer of an organic electronic device including an organic light emitting device, and an organic electronic device including an organic light emitting device, which uses the novel compound, shows excellent characteristics in efficiency, driving voltage, stability, and the like. In particular, the novel compound according to the present specification has excellent thermal stability, deep HOMO level and hole stability thereby shows excellent characteristics. The novel compound can be used in an organic electronic device including an organic light emitting device either alone or by being mixed with an n-type dopant such as LiQ. The novel compound according to the present specification improves the efficiency, and improves the stability of a device due to the thermal stability of the compound.
REFERENCES
[0000]
1 : Substrate
2 : Anode
3 : Light Emitting Layer
4 : Cathode
5 : Hole Injection Layer
6 : Hole Transfer Layer
7 : Electron Transfer Layer
|
The present specification provides a novel fluoranthene compound significantly improving the life span, efficiency, electrical and chemical stability and thermal stability of an organic electronic device, and an organic electronic device that contains the compound in an organic compound layer.
| 7
|
FIELD OF THE INVENTION
This invention relates to multilevel metal interconnections on an integrated circuit chip and more particularly to vias, studs, or riser wires between conductors of respective levels of metal interconnections with reduced electromigration failures.
BACKGROUND OF THE INVENTION
The current metalization used in multilevel metal interconnections by some manufacturers include aluminum-copper lines for each level of metalization and tungsten vias or studs between conductors of respective levels of metal interconnections. The use of Cu solute additions to Al is desirable because it reduces the rate of electromigration and stress-voiding. The amount of Cu addition Al, however, is limited by the ability to reactive ion etch the Al(Cu) line to ≦2 wt. % Cu. The tungsten studs act as a complete barrier to copper and aluminum atoms which may be moved or transported at high current densities in the conductors, resulting in copper and/or aluminum depletion adjacent to tungsten studs which, in turn leads to electromigration open failures. To avoid electromigration open failures, a set of downstream ground rules for electrical current is required to limit the current densities in the conductors. The ground rules, however, limit the performance of advanced complementary metal oxide semiconductor (CMOS) logic chips. One solution to this problem is to replace the tungsten stud or via with aluminum, or some other low resistivity material through which aluminum or copper can diffuse or be transported. The main difficulties with an aluminum stud are finding a technique which can be used to fill high aspect ratio holes with aluminum to form the studs or vias. A number of methods have been investigated, such as chemical vapor deposition (CVD), electron cyclotron resonance (ECR), columnated sputtering, hot sputtering and various electro deposition techniques. With the foregoing methods, however, there are subsequent integration, throughput or thermal budget problems.
Another option is to use copper studs or vias. Filling of extremely high aspect ratio holes, greater than 3, has been recently demonstrated using plating with an (ECR) copper/tantalum liner i.e. B. Luther et al. Proceedings IEEE VLSI Multilevel Interconnections Conference, Santa Clara, California Jun. 8-9, 1993 p.15. The problem with pure copper studs or vias is that aluminum and copper react at about 250° C. to form Al 2 Cu with a 2.8% volume expansion. A barrier layer placed on top of the studs sufficient to prevent a reaction between the copper stud or via and the aluminum lines or conductors would also decrease the electromigration lifetime, in a similar manner as a tungsten stud or via, by preventing aluminum or copper atoms from being transported through the barrier layer in regions with high current density. Additionally, the thickness of the barrier layers on the aluminum lines or conductors would increase the line height or conductor height and hence the interlevel capacitance between adjacent conductors. If the barrier layer were to fail during subsequent processing, the copper and aluminum would react forming Al 2 CU with the associated volume increase of 2.8% which would cause delamination at the metal/oxide or insulator interface.
In U.S. Pat. No. 5,010,039 which issued on Apr. 23, 1991 to S-M Ku et al., describes methods of forming contacts to a semiconductor device where via holes are etched through a deposited first insulation layer on a semiconductor chip with defined contact areas below, then sputtered, evaporated or CVD deposition of an Al/Cu alloy is performed to fill the via holes to make a contact stud. The deposited surface may then be chemical-mechanical polished to planarity.
In U.S. Pat. No. 5,071,714 which issued on Dec. 10, 1991 to K. P. Rodbell et al., a multilayered intermetallic connection for semiconductor devices is described wherein aluminum/copper alloy, less that 2% copper, is deposited on a thin layer of Ti, and another layer of Ti is subsequently deposited on top of the AlCu prior to a final cap layer of Al/Cu or Al. The layers are deposited over semiconductor contact areas and are subsequently annealed to form TiAl 3 layers on both the top and bottom AlCu surfaces.
In U.S. Pat. No. 4,884,123 which issued on Nov. 28, 1989 to P. Dixit et al. entitled "Contact Plug and Interconnect Employing a Barrier Lining and a Backfilled Conductor Material", via holes are etched through a first insulator layer on a semiconductor surface over defined contact areas, and then the via interior is flashed with a thin deposit of Ti or TiN, followed by a deposition of Al/Cu, with 1% copper in alloy, to fill and form the contact plug. A second patterned metal layer may be formed contacting the formed Al/Cu contact plugs after planarization.
In U.S. Pat. No. 4,335,506 which issued on Jun. 22, 1982 to G. T. Chiu, a layer of Cu is lift-off deposited onto an Al layer, then the resist is removed and the exposed Al is etched away using the Cu layer as an etch mask. The remaining Al layer with the Cu layer above is annealed to forman Al/Cu alloy metalization and contacts. The step of annealing causes the copper to diffuse into, and alloy with the aluminum layer.
SUMMARY OF THE INVENTION
In accordance with the present invention, an interconnect structure for an integrated circuit for resisting electromigration as high current densities pass through interlayer contact regions of the interconnect structure is described comprising a first patterned interconnect layer having a first metal selected from the group consisting of copper, copper alloys, aluminum and aluminum alloys formed over a first insulation layer and over first electrical contact regions, vias or studs passing through the first insulation layer, a second insulation layer formed over the first patterned interconnect layer and the first insulation layer, the second insulation layer having openings therein with second electrical contact regions, vias or studs therein for making electrical contact with the first patterned interconnect layer, and a second interconnect layer having a second metal selected from the group consisting of copper, copper alloys, aluminum and aluminum alloys formed over the second insulation layer and over the second electrical contact regions, vias or studs, the second electrical contact regions, vias or studs comprising substantially the compound Al 2 Cu in the theta phase. It is understood that if copper or a copper alloy is used as the interconnect levels then a barrier layer would be required between the Al 2 CU stud and the Cu layers. Otherwise the Al 2 CU will decompose.
The invention further provides a method for forming interconnections on an integrated circuit chip starting with a dielectric surface with contact regions, vias or studs such as tungsten studs connecting to silicon devices on the chip comprising the steps of: sputter depositing a layer of titanium followed by a layer of Al-Cu where Cu is about 0.5 wt. % of the Al-Cu layer followed by a layer of Ti followed by a layer of TiN to form a first composite metal layer. The composite layer is subsequently patterned into metal lines and annealed at 200° C. for a minimum of 20 minutes (at 360° C.). During this anneal, the Ti reacts with the Al-Cu forming TiAl 3 intermetallic compound along both the bottom and top interfaces of the Al-Cu layer. Next, a first insulator layer is formed over and thicker than the first composite metal layer and filling all spaces between metal lines in the pattern of the first composite metal layer to form a generally planarized insulator. A Chemical Mechanical Polish (CMP) can also be used to ensure a planarized insulator. Next, defining and forming contact holes in the first insulator layer down to selected areas on the top of the pattern of metal lines formed from the first composite metal layer. In the contact holes, the top TiN and TiAl 3 layers may be removed after forming the contact holes in the first insulator layer. The holes and removal of layers may be accomplished or drilled by reactive ion etching (RIE). Next, the contact holes are filled with Cu such as by chemical vapor deposition (CVD), electrolytic plating, ECR deposition or an electroless Cu processes. Next, a Cu-chemical mechanical polish (CMP) is used to plannarize and to remove any Cu from the dielectric layer. Next, forming Al or Al alloy as a blanket film on top of the first insulation layer and covering all of the Cu filled vias or studs with the blanket film such as by sputtering or evaporation. Alternately, this step may be deleted. Next, annealing the Cu to form Al 2 CU in the vias or studs by reaction with aluminum atoms from the layer above or from the metal lines of the first composite layer below. The annealing temperature typically may be in the range from 200° C. to 400° C. for a time period from 20 to about 60 minutes. Next, the unreacted Al or Al-Cu may be removed from the top surface of the first insulator layer such as by using a wet etch, RIE or CMP. Also, Al 2 CU extending above the contact holes may be removed by CMP. The foregoing steps may be repeated to form additional levels of interconnection.
The invention further provides metal vias or studs of Al 2 Cu in the theta phase which has a resistivity of 8 micro-Ohm-cm which is less than the resistivity of tungsten studs or vias which have a resistivity in the range from 10 to 13 micro-Ohm-cm.
The invention further provides metal vias or studs of Al 2 Cu in the theta phase between patterned metallic layers which serve as a source and path for Cu to move to both the upper and lower Al-Cu lines to reduce the susceptibility to electromigration and thermal voiding as compared to tungsten.
The invention further provides metal vias or studs of Al 2 Cu in the theta phase which may be uncovered during subsequent etching since Al 2 Cu is an excellent etch stop.
BRIEF DESCRIPTION OF THE DRAWING
These and other features, objects, and advantages of the present invention will become apparent upon consideration of the following detailed description of the invention when read in conjunction with the drawing in which:
FIG. 1 is one embodiment of the invention.
FIGS. 2 through 6 show steps in forming the embodiment of FIG. 1.
FIG. 7 shows a cross-section view of an interconnect structure fabricated in the laboratory.
FIG. 8 is a binary phase diagram for Al-Cu.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, FIG. 1 shows interconnect structure 10 above semiconductor chip 14.
Referring to FIG. 1, interconnect structure 10 is shown for resisting electromigration as high current densities pass through interlayer contact regions or studs 12 and 13. Interlayer contact region or studs 12 and 13 comprises substantially the compound Al 2 Cu in the theta phase. Interlayer contact regions 12 and 13 may thus allow the transport of copper atoms and aluminum atoms due to very high current densities to and from adjacent wiring layers. As shown in FIG. 1, a semiconductor chip may have a substrate 15 with p and n impurity regions formed therein and in ohmic contact with contact regions 16 and 17 which may be, for example, titanium silicide for interconnecting to p and n regions. A layer of insulation 20 may be formed over substrate 15 and may be silicon dioxide or silicon nitride. Substrate 15 may be a semiconductor such as silicon, silicon germanium alloy, or germanium or some other semiconductor material. An insulation layer 22, for example, silicon dioxide may be formed over insulation layer 20 and contact regions 16 and 17. Openings may be formed in insulation layer 22 and subsequently filled with a metalization to make ohmic contact with contact regions 16 and 17. The metalization may be tungsten which provides a barrier to copper atoms. As shown in FIG. 1 contact regions 16 and 17 are connected to electrical contact regions or studs 24 and 25. Insulation layer 22 may have an upper surface 23 which is also co-planar with the upper surface of electrical contact regions 24 and 25. The upper surface 23 of insulation layer 22 may be formed by chemical-mechanical polish (CMP) and may be substantially planar.
The integrated circuit chip 14 may now be connected by way of an interconnect structure 10 formed above upper surface 23. Wherein upper surface 23 has a plurality of contact regions such as 24 and 25.
A first patterned interconnect layer 30 may be formed on upper surface 23 such as by a blanket deposition of a metal selected from the group consisting of copper, copper alloys, aluminum and aluminum alloys. The blanket layer may be photolithographically patterned by way of photoresist and etching to form the first patterned interconnect layer 30. In the case of copper, damascene patterns would be used. The thickness of the metal lines or height may be determined by the thickness of the blanket layer of metal and may be in the range from 100 nm to 1500 nm. An insulation layer 34 may be formed over first patterned interconnect layer 30 and over upper surface 23 having a thickness to cover first patterned interconnect layer 30 and may be in the range from layer 30 thickness to 3000 nm. Insulation layer 34 is typically planarized and may have a greater thickness than the thickness of first patterned interconnect layer 30. Insulation layer 34 may be, for example, silicon dioxide, silicon nitride, polyimide and diamond-like carbon. Insulation layer 34 may have openings 36 formed therein to expose portions of first patterned interconnect layer 30 wherein interconnections are desired. Openings 36 may be formed by reactive ion etching (RIE). The openings are subsequently filled with copper which is planarized and annealed at a temperature to allow aluminum atoms to react with the copper to form Al 2 Cu in the theta phase in regions or studs 12 and 13. The copper may require a thin adhesion layer which would be from the group of refractory metals Ti, Ta, TiN, etc. A sacrificial layer of Al or Al alloy would be deposited on top of the Cu to serve as a source of Al to form Al 2 Cu. This can then be removed prior to the deposition of layer 40.
The second patterned interconnect layer 40 is formed over upper surface 35 of insulation layer 34 and over interlayer contact regions or studs 12 or 13. The second patterned interconnect layer 40 may be formed by first forming a blanket deposit of metal selected from the group consisting of copper, copper alloys, aluminum and aluminum alloys. A photoresist layer may be formed over the blanket layer of metal, exposed and developed. The blanket layer may be etched using the photoresist as a mask. The photo resist may be subsequently removed. The height or thickness of the second pattern interconnect layer 40 may be determined by the thickness of the blanket layer of metal deposited prior to patterning and may be in the range from 100 to 1500 nm.
While FIG. 1 shows first patterned interconnect layer 30 and second pattern interconnect layer 40, additional patterned interconnect layers may be added by repeating the structure shown between first patterned interconnect layer 30 and second patterned interconnect layer 40.
FIGS. 2 through 6 shows steps in forming the embodiment of FIG. 1. In FIGS. 2 through 6 like references are used for functions corresponding to the apparatus of FIG. 1. Electrical contact region 24 may be tungsten which provides a barrier to the diffusion of Al and copper atoms towards substrate 15 shown in FIG. 1. First patterned interconnect layer 30 may be formed by sputter depositing a blanket layer of titanium 46 followed by a layer of aluminum-copper 47 followed by a layer of titanium 48 followed by a layer of titanium nitride TiN 49. Layer 49 of titanium nitride provides an anti-reflection coating useful for preventing reflection of light when first patterned interconnect layer 30 is patterned. Layers 46 through 49 comprising first patterned interconnect layer 30 after patterning are annealed at 400° centigrade for a minimum of 20 minutes. During this step of annealing, the titanium layers 46 and 48 react with the aluminum in layer 47 forming TiAl 3 in a metallic compound along both the bottom and top interfaces of layer 47. Layers 46 and 48 initially of titanium are reacted to form TiAl 3 .
Next, an insulation layer 34 such as silicon dioxide is applied over first patterned interconnect layer 30 such as by a PECVD (Plasma Enhanced Chemical Vapor Deposited) oxide 34 and over first patterned interconnect layer 30 which results in a planarized insulator having high aspect features filled with oxide in the first patterned interconnect layer 30. Planarization of insulation layer 34 may be achieved by RIE or by CMP.
Next, openings 36 are drilled or formed in insulation layer 34 down to the top of first patterned interconnect layer 30. Openings 36 and subsequent studs 12 and 13 may be in the range from 100 to 2000 nm in height. In forming openings 36, the alignment of the openings to the first patterned interconnect layer 30 may not be perfect as shown in FIG. 2. Further, layer 49 and 48 may be removed during the drilling or forming of opening 36 which may be formed by RIE.
Next, as shown in FIG. 3, opening 36 including the walls and bottom of opening 36 have a thin adhesion layer 52 of a refractory metal such as tantalum formed thereon for adhesion. Next a copper seed layer 53 can be formed over adhesion layer 52 such as by sputtering. Opening 36 may be completely filled by electroless or electrolytic plating copper using copper seed layer 53 as an electrode during the electrolytic plating process. Alternately, in place of copper seed layer 53, opening 36 may be filled with copper completely by bias sputtering, hot evaporation, CVD, etc.
Next, as shown in FIG. 4, adhesion layer 52, copper seed 53 and copper 54 is removed from upper surface 35 such as by chemical mechanical polish.
Next, as shown in FIG. 5, copper 54 in opening 36 may be annealed at a temperature in the range from 200° centigrade to 548° centigrade to form Al 2 Cu in the theta phase. The aluminum atoms are supplied by diffusing from layer 47 through the adhesion layer 52, copper seed layer 53 and copper layer 54. Since Al 2 Cu has a 2.8 percent volume expansion with respect to Cu alone, the material in opening 46 will extrude upwards and form a mushroom above upper surface 35 which may be subsequently removed by a brief chemical-mechanical polish.
In an alternate method, prior to annealing copper 54, a blanket layer 58 may be formed on upper surface 35 and on the upper surface 55 of copper 54 shown in FIG. 6. Blanket layer 58 may be formed by sputtering or by evaporation. The material in opening 36 namely copper 54 may be converted to Al 2 Cu in the theta phase by annealing in the range from 200° C. to 548° C. for 60 minutes (at 400° C.). Blanket layer 58 as well as layer 47 will provide aluminum atoms by way of diffusion into copper 54 thereby enabling Al 2 Cu to be formed in place of copper 54 and copper seed layer 53, if present. At the same time copper atoms from copper 54 will diffuse into blanket layer 58 and layer 47. Next, the unreacted Al-Cu or Al on upper surface 35 and above opening 36 is removed using a wet etch, RIE or chemical-mechanical polish or combinations thereof. This method would be required if layer 47 was copper.
The resulting structure from the process steps shown in FIGS. 2-6 is interlevel contact regions or studs 12 and 13 shown in FIG. 1 which comprise Al 2 Cu. Interlayer contact regions or studs 12 and 13 comprised of Al 2 Cu are in the theta phase and would have a resistivity of 8 micro-Ohm-cm which is less than that of tungsten vias which would have a resistivity in the range from 10 to 13 micro-Ohm-cm. Since the Al 2 Cu studs are formed reactively they also have a lower contact resistance than the W studs.
Next, as shown in FIG. 1, a second patterned interconnect layer 40 may be formed comprising first depositing a thin titanium layer 66 for adhesion, depositing an aluminum-copper layer 67, depositing thereover a titanium layer 68 followed by a titanium nitride layer 69 which functions as an anti-reflection coating. The blanket layers 66 through 69 may be patterned by applying and developing photoresist to form a mask and etching through the mask.
Layers 66 through 69 may be formed by the same processes and to the same thicknesses as layers 46 through 49. Additional levels of metallization may be added by repeating the steps described herein starting with the step of forming an insulation layer 34 (which may be the same as layer 34 described previously) over second patterned interconnect layer 40.
FIG. 7 shows a cross section view of an interconnect structure fabricated in the laboratory taken with a scanning electron microscope (SEM). In FIG. 7 like references are used for functions corresponding to the apparatus of FIGS. 1 through 6. The width or diameter of interlayer contact region 12 is about one micron wide as shown by arrow 74. The cross section view was taken after forming Al 2 Cu (12) by annealling Cu in contact with an Al line (47) and blanket Al film 58. First patterned interconnect layer 30 shows a TiN layer 49 on either side of interlayer contact region 12 on the top surface of layer 30. FIG. 7 shows interlayer contact region 12 of Al 2 Cu and that some Cu diffused into layers 30 and 40 to form Al 2 Cu precipitates 76 and 78 below and above region 12. A second precipitate 80 and 82 in layers 30 and 40 to the right of region 12 were formed with respect to another contact region of Al 2 Cu out of view to the right of contact region 12. Layer 30 was comprised of Al-Cu where Cu was 0.5% weight. Insulation layer 34 was silicon dioxide. FIG. 7 shows the Al 2 Cu formation prior to removal of the top sacrificial Al (or AlCu) layer. Additionally there appears to be some damage to the lower interface during SEM sample preparation.
It was disclosed by Q. Z. Hong and F. M. d'Heurle, at the Materials Research Symposium 1992 Fall Meeting, that Cu is a dominant diffusing species in Al 2 Cu formation and that the reaction is a function of temperature. At 200° centigrade the ratio of Cu/Al moving species is 3 to 1 whereas at 400° centigrade the ratio of Cu/Al moving species is closer to 1 to 1. Therefore, it is possible to choose an annealing temperature which balances the mass flux to avoid void formation yet allows for the reaction in opening 36 to proceed to completion. Further, it is noted that the theta-phase-studs 12 and 13 will be in equilibrium with layers 47 and 67 of Al-Cu where Cu may be 2 percent weight and therefore may dissolve with additional annealing cycles to satisfy the Al layers 47 and 67 solubility. This has been beneficial since the theta-phase-studs 12 and 13 will then serve as a Cu source for the Al-Cu layers 47 and 67. Layers 47 and 67 would thus be less susceptible to electromigration and less sensitive to thermal voiding than, for example, if the studs 12, 13 were tungsten which provides a barrier to copper and Al. The lower susceptibility is due to Cu and Al being able to diffuse through Al 2 Cu whereas W is impermeable to Cu and Al at normal operating and processing temperatures.
Additionally, during processing, interlayer contact regions 12 and 13 of Al 2 Cu may be uncovered since Al 2 Cu is difficult to etch (wet etch or RIE). Thus, the presence of Al 2 Cu studs 12 and 13 would be very advantageous during the Al-Cu RIE of the second patterned interconnect layer 40 since studs 12 and 13 may be exposed or uncovered. Al 2 Cu is also much more difficult to etch (wet etch or RIE) than Al so stud removal during the etching of second patterned interconnect layer 40 or during over-etch would be greatly reduced.
FIG. 8 is a binary phase diagram for Al-Cu showing that Al 2 Cu in the theta phase forms when Cu is annealed in an Al rich environment. In FIG. 8, the theta phase is shown to be bounded by lines 86-88 and to occur in the range from 53% to 54% weight Cu. Al 2 Cu in the theta phase is stable up to 590° C. At the eutectic temperature of 548.2° C., the composition range is in the range from 31.9 to 32.9 atomic percent Cu. For further information about Al 2 Cu in the theta phase, reference is made to T. B. Massalski, Binary Alloy Phase Diagrams, published by American Society For Metals, Metals Park, Ohio 44073 (1986) pages 106 and 107 which are incorporated herein by reference.
While there has been described and illustrated an interconnect structure formed on an integrated circuit chip for resisting electromigration by providing interlayer contact regions of Al 2 Cu in the theta phase between patterned interconnect layers of Al-Cu or Al, it would be apparent to those skilled in the art that modifications and variations are possible without deviating from the broad scope of the invention which shall be limited solely by the scope of the claims appended hereto.
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An interconnect structure and method for an integrated circuit chip for resisting electromigration is described incorporating patterned interconnect layers of Al or Al-Cu and interlayer contact regions or studs of Al 2 Cu between patterned interconnect layers. The invention overcomes the problem of electromigration at high current density in the interconnect structure by providing a continuous path for Cu and/or Al atoms to move in the interconnect structure.
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1. PRIORITY CLAIM
[0001] This application claims the benefit of priority to the following U.S. provisional patent applications:
[0000] U.S. Patent Application No. 61/569,621, filed 12 Dec. 2011, under attorney docket number 14528.00045;
U.S. Patent Application No. 61/587,521, filed 17 Jan. 2012, under attorney docket number 14528.00425; and
U.S. Patent Application No. 61/595,546, filed 6 Feb. 2012, under attorney docket number 14528.00460.
2. TECHNICAL FIELD
[0002] This disclosure relates to communication devices with multiple Subscriber Identity Modules (SIMs). The disclosure also relates to enhanced time tracking in communication devices with multiple SIMs.
3. BACKGROUND
[0003] Rapid advances in electronics and communication technologies, driven by immense customer demand, have resulted in the widespread adoption of mobile communication devices. The extent of the proliferation of such devices is readily apparent in view of some estimates that put the number of wireless subscriber connections in use around the world at nearly 80% of the world's population. Furthermore, other estimates indicate that (as just three examples) the United States, Italy, and the UK have more mobile phones in use in each country than there are people living in those countries.
[0004] Relatively recently, cellular phone manufactures have introduced phone designs that include multiple SIM cards. Each SIM card facilitates a separate connection to the same network or different networks. As a result, the SIMs provide the owner of the phone with, for example, two different phone numbers handled by the same phone hardware. Accordingly, the multiple SIM approach alleviates to some degree the need to carry different physical phones, and improvements in multiple SIM communication devices will continue to make such devices attractive options for the consumer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The innovation may be better understood with reference to the following drawings and description. In the figures, like reference numerals designate corresponding parts throughout the different views.
[0006] FIG. 1 shows an example of user equipment with multiple SIMs.
[0007] FIG. 2 shows an example of a paging block and the bits of the paging block.
[0008] FIG. 3 shows an example of determining timing error using the paging block.
[0009] FIG. 4 shows an example of user equipment including multiple SIMS where the scheduled reception of paging blocks for each SIM may collide.
[0010] FIG. 5 shows an example an example of user equipment including multiple SIMS where the time tracking logic uses timing information from the paging blocks of SIM 1 to update the timing offset.
[0011] FIG. 6 shows an example an example of user equipment including multiple SIMS where the time tracking logic uses timing information from the paging blocks of SIM 1 and SIM 2 to update the timing offset.
[0012] FIG. 7 shows another example an example of user equipment including multiple SIMS where the time tracking logic uses timing information from the paging blocks of SIM 1 and SIM 2 to update the timing offset.
[0013] FIG. 8 shows another example an example of user equipment including multiple SIMS where the time tracking logic uses timing information from the paging blocks of SIM 1 to update the timing offset.
[0014] FIG. 9 shows an example an example of user equipment including multiple SIMS where the time tracking logic uses timing information from the paging blocks of SIM 1 and SIM 2 to update the timing offset.
[0015] FIG. 10 shows another example an example of user equipment including multiple SIMS where the time tracking logic uses timing information from the paging blocks of SIM 1 and SIM 2 to update the timing offset.
[0016] FIG. 11 shows an example of a flow diagram of time tracking logic that user equipment may implement in hardware, software, or both.
DETAILED DESCRIPTION
[0017] The discussion below makes reference to user equipment. User equipment may take many different forms and have many different functions. As one example, user equipment may be a cellular phone capable of making and receiving wireless phone calls. The user equipment may also be a smartphone that, in addition to making and receiving phone calls, runs general purpose applications. User equipment may be virtually any device that wirelessly connects to a network, including as additional examples a driver assistance module in a vehicle, an emergency transponder, a pager, a satellite television receiver, a networked stereo receiver, a computer system, music player, or virtually any other device. The discussion below addresses how to track symbol timing in user equipment that includes multiple (e.g., two) SIMs.
[0018] FIG. 1 shows an example of user equipment 100 with multiple SIMs, in this example the SIM 1 102 and the SIM 2 104 . An electrical and physical interface 106 connects SIM 1 102 to the rest of the user equipment hardware, for example, to the system bus 110 . Similarly, the electrical and physical interface 108 connects the SIM 2 to the system bus 110 .
[0019] The user equipment 100 includes a communication interface 112 , system logic 114 , and a user interface 118 . The system logic 114 may include any combination of hardware, software, firmware, or other logic. The system logic 114 may be implemented, for example, in a system on a chip (SoC), application specific integrated circuit (ASIC), or other circuitry. The system logic 114 is part of the implementation of any desired functionality in the user equipment. In that regard, the system logic 114 may include logic that facilitates, as examples, running applications, accepting user inputs, saving and retrieving application data, establishing, maintaining, and terminating cellular phone calls, wireless network connections, Bluetooth connections, or other connections, and displaying relevant information on the user interface 118 . The user interface 118 may include a graphical user interface, touch sensitive display, voice or facial recognition inputs, buttons, switches, and other user interface elements.
[0020] The communication interface 112 may include one or more transceivers. The transceivers may be wireless transceivers that include modulation/demodulation circuitry, amplifiers, analog to digital and digital to analog converters and/or other logic for transmitting and receiving through one or more antennas, or through a physical (e.g., wireline) medium. As one implementation example, the communication interface 112 and system logic 114 may include a BCM2091 EDGE/HSPA Multi-Mode, Multi-Band Cellular Transceiver and a BCM59056 advanced power management unit (PMU), controlled by a BCM28150 HSPA+ system-on-a-chip (SoC) baseband smartphone processer. These integrated circuits, as well as other hardware and software implementation options for the user equipment 100 , are available from Broadcom Corporation of Irvine Calif.
[0021] The transmitted and received signals may adhere to any of a diverse array of formats, protocols, modulations, frequency channels, bit rates, and encodings that presently or in the future support communications including paging notifications associated with SIMs. As one specific example, the communication interface 112 may support transmission and reception under the Universal Mobile Telecommunications System (UMTS). The techniques described below, however, are applicable to other communications technologies that include paging whether arising from the 3rd Generation Partnership Project (3GPP), GSM (R) Association, Long Term Evolution (LTE)™ efforts, or other partnerships or standards bodies.
[0022] In order for user equipment 100 to reliably transmit and receive data over a network, user equipment 100 may synchronize its internal timing with the timing of a base transceiver station (BTS) on the network. User equipment 100 may synchronize with the timing from a BTS of the network by aligning an internal time base 140 of the user equipment 100 with the timing information received from the BTS. In order to assist with synchronization, the BTS may periodically send timing information to the user equipment 100 so that the user equipment 100 can correct its internal time base 140 . In order to receive the timing information, the user equipment 100 may actively listen on the synchronization channel or may periodically listen on the paging channel.
[0023] The user equipment 100 may connect with a network in either active mode or idle mode. When user equipment 100 connects to a network in active mode, user equipment 100 is in frequent communication with the network and frequently receives timing information from the network. When the network connection is in idle mode, the user equipment 100 can remain in a reduced power “sleep” mode, “waking up” periodically to listen for synchronization information contained on the paging channel of the network. User equipment 100 may utilize multiple internal time bases, including, for example, an active mode time base 142 and an idle mode time base 144 . The active mode time base 142 may be more accurate than the idle mode time base 144 . The active mode time base 142 may be used while the user equipment is connected to a network in active mode and actively transmitting/receiving data. User equipment 100 may have an idle mode time base 144 that is used when user equipment 100 is connected to the network in idle mode and not actively transmitting/receiving data. User equipment 100 may use idle mode time base 142 to determine the particular time that user equipment 100 should wake up from sleep mode. Due to the fact that the active mode time base 142 may be more accurate and may consume additional power, the user equipment 100 may, while in sleep mode, power down the active mode time base 142 .
[0024] During periods when user equipment 100 is in sleep mode and does not receive timing information from the BTS, user equipment 100 may rely on its internal time base 140 . However, internal time base 140 may be inaccurate and may “drift” with respect to the timing of the BTS. The time drift may be due to phase error or frequency error with respect to the phase and/or frequency of the BTS. If user equipment 100 does not periodically wake up to listen for the synchronization information contained in the paging block from the network, the user equipment 100 may lose synchronization with the network. As a result, the user equipment 100 may not receive a paging indicator from the network and may miss a call, message, or data that the network has designated for the user equipment 100 .
[0025] When in idle mode, user equipment 100 may be scheduled to wake up at a specified interval to receive the synchronization information contained in the paging block from the network. The specified interval may be based on a background paging schedule (BPS). As one example of the background paging schedule, the network's discontinuous reception cycle (DRX) interval may be used as the background paging schedule. The BPS provides the length of time specified by the network during which the user equipment 100 remains asleep between periods of listening for the synchronization information contained in the paging block. The length of time for the BPS may vary, depending on the type of communication technology used (e.g., GSM, CDMA, UMTS, etc.) and the particular settings used by the particular service provider that operates the network. As one example for one network, the BPS may be 2 seconds, while for other networks, the BPS may be shorter or longer.
[0026] Synchronization information from the network may be contained in a paging block sent from the BTS to the user equipment 100 on the paging channel. FIG. 2 shows an example of paging block 202 . Paging block 202 may contain bursts of data in the paging block. For example, the burst 210 is contained in the paging block 202 . Burst 210 includes data bits 212 and midamble 220 . The midamble is a known sequence of bits, such as a training sequence, that may be contained in each burst of paging block 202 . Midamble 220 can be used for synchronization because the midamble arrives at a known location within each burst. When the user equipment 100 identifies and locates the midamble, the user equipment 100 can identify the start position and/or stop position of the data burst.
[0027] FIG. 3 shows an example of using midamble 220 to determine a timing error 306 . The user equipment 100 may use its internal time base 140 to predict the arrival of midamble 220 at predicted arrival time 302 . Once the user equipment 100 identifies midamble 220 , the user equipment 100 identifies the actual arrival time 304 of midamble 220 . The time difference between the predicted arrival time 302 and actual arrival time 304 results in the timing error 306 . User equipment 100 may use timing error 306 to compensate the internal time base 140 when predicting the arrival time of the next paging block.
[0028] In order to predict the arrival time of the next paging block, user equipment 100 may use a time tracking loop. The time tracking loop may correct for the drift in the internal time base 140 . The time tracking loop may apply a correction factor to account for the timing drift of the internal time base 140 . The correction factor may be updated each time user equipment 100 receives a paging block and determines timing error 306 from the burst.
[0029] Where a user equipment has multiple SIMs for connecting to multiple networks, the user equipment may require synchronization with multiple BTS's on multiple networks. Each network (e.g., network 130 or 132 ) may supply its own timing information, and the BPS may have a different time period for each network. User equipment 100 may track the timing difference that may exist between the user equipment's internal time base 140 and the timing for each network. As a result, the user equipment 100 may apply a different correction factor for each network with which it is synchronized. As will be described in more detail below, user equipment 100 may use the timing information received from one network, either network, or both networks when tracking the timing correction factor for the user equipment 100 .
[0030] In some implementations, user equipment 100 may share radio frequency resources between multiple SIMs. As a result, both SIMs cannot simultaneously receive paging blocks from the network. Because both SIMs may not simultaneously receive paging blocks from the network, in situations, for example, where user equipment 100 is scheduled to receive a paging block from SIM 1 network 130 at the same time user equipment 100 is scheduled to be receive a paging block from SIM 2 network 132 , the paging blocks “collide.” When the paging blocks from multiple networks collide, user equipment 100 may choose whether to receive the paging block from SIM 1 network 130 , SIM 2 network 132 , or neither. As a result, one or both paging blocks may be ignored or lost. If user equipment 100 ignores or loses a paging block, user equipment may wait for the next scheduled paging block.
[0031] FIG. 4 shows an example of “collisions” between paging blocks from multiple networks. Timing graph 400 shows a schedule of paging blocks from SIM 1 network 130 and SIM 2 network 132 that are designated for user equipment 100 . Paging blocks 402 , 404 , and 406 are scheduled by SIM 1 network 130 at BPS 1 time interval 401 . Paging blocks 412 , 414 , 416 are scheduled by SIM 2 network 132 at BPS 2 time interval 411 . Based on the schedule, paging block 402 and paging block 412 are scheduled to arrive at user equipment 100 in a partially overlapping manner, indicated by timing overlap 420 . Because paging block 402 and paging block 412 are scheduled to collide (i.e., overlap), user equipment 100 may choose to receive paging block 402 , paging block 412 , or neither. Similarly, paging block 404 and paging block 416 are scheduled to arrive at user equipment 100 at the same time, indicated by timing overlap 432 . Because paging block 404 and paging block 416 are scheduled to collide, user equipment 100 may choose to receive paging block 404 , paging block 416 , or neither. As a result of the collisions, user equipment 100 may lose opportunities to receive timing information from either SIM 1 network 130 or SIM 2 network 132 . When paging blocks collide and user equipment 100 waits for additional paging blocks, the internal time base may drift further out of synchronization with the network. As a result of lost paging blocks, user equipment 100 may not be able to update the timing correction factor as frequently as desired. Thus, the user equipment may lose synchronization between the user equipment 100 and network 130 or 132 . System logic 114 provides certain advantages.
[0032] In one implementation, the system logic 114 includes one or more processors 116 and a memory 120 . The memory 120 stores, for example, time tracking logic 122 that the processor 116 executes. The memory 120 may also store SIM 1 network timing information 124 , SIM 2 network timing information 126 , and time tracking parameters 128 . As will be described in more detail below, the time tracking logic 122 facilitates timing correction so that user equipment 100 can more accurately synchronize with each network, even when some paging blocks collide.
[0033] The time tracking logic 122 may independently track the drift of internal time base 140 for each network with which user equipment 100 is connected. The time tracking logic 122 may independently track the time base drift by having independent tracking loops for each network. For example, if user equipment 100 is connected in idle mode to SIM 1 network 130 , the time tracking logic 122 may use the timing error determined from paging blocks received from SIM 1 network 130 . Using the timing error from paging blocks received from SIM 1 network 130 , the time tracking logic 122 may apply an appropriate correction factor to the internal time base 140 . Similarly, if user equipment 100 is connected in idle mode to SIM 2 network 132 , the time tracking logic 122 may use the timing error determined from paging blocks received from SIM 2 network 132 . Using the timing error from paging blocks received from SIM 2 network 132 , the time tracking logic 122 may apply an appropriate correction factor to the internal time base 140 .
[0034] In another implementation, the time tracking logic 124 may track the drift of internal time base 140 by combining—into a single tracking loop—the timing error determined from paging blocks received from the multiple networks with which user equipment 100 may be connected. For example, if user equipment 100 is connected to SIM 1 network 130 and SIM 2 network 132 , the time tracking logic 122 may use the SIM 1 network paging blocks and SIM 2 network paging blocks in order to determine the appropriate time base compensation for synchronizing user equipment 100 with SIM 1 network 130 and SIM 2 network 132 . In particular, by combining the timing error determined from paging blocks received from multiple networks, the user equipment is able to take advantage of timing information received from both networks in order to more frequently update the timing compensation and more accurately synchronize the timing of the user equipment 100 to the timing of the network, even when some paging blocks collide and/or are lost.
[0035] The time tracking logic 122 may use certain time tracking parameters 128 in order to utilize timing error determined from paging blocks received from multiple networks for improved time tracking. The time tracking logic 122 may store the time tracking parameters 128 in memory 120 and update the time tracking parameters 128 as the processor 116 calculates and processes the timing information. For example, when user equipment 100 is in idle mode, each time a paging block is received from SIM 1 network 130 or SIM 2 network 132 , the time tracking logic 122 may update the time tracking parameters 128 .
[0036] In one implementation, example time tracking parameters 128 may include:
[0000]
TABLE 1
Parameter
Variable
Type
Description
α 1
constant
Gain of the first order phase locked loop.
This constant may be used to stabilize the
loop and may be set to a rational number
less than one
α d
constant
Gain of the “delta loop.” This constant
may be used to stabilize the loop and may
be set to a rational number less than one
n
index
An index representing receipt of the current
paging block; n + 1 is the next scheduled
paging block
i(n)
input
Network Identification (e.g., SIM1 network
or SIM2 network) for the n-th paging block
ê(n)
input
The measured timing error from the n-th
paging block
c
internal state
First order loop filter output, representing
variable
the timing adjustment due to phase error
d
internal state
The differential adjustment applied when
variable
the next scheduled paging block is from a
different network
δ
internal
Timing adjustment between the previous
variable
paging block and the current paging block
[0037] In one implementation, using the time tracking parameters 128 listed above, the time tracking logic 122 may implement the following algorithm:
[0000]
TABLE 2
for n = 1,2, ...
% calculate loop filter output (phase error timing adjustment)
c = α 1 ê(n);
% update differential adjustment
d = d + (−1) i(n) α d c;
% determine time base adjustment based on phase timing error
if
i(n + 1) == i(n)
then δ = c;
elseif
i(n + 1) == 1
then δ = c − d;
elseif
i(n + 1) == 2
then δ = c + d;
end
[0038] FIG. 5 shows an example timing graph 500 that includes a series of paging blocks from SIM 1 network 130 and SIM 2 network 132 that are scheduled for user equipment 100 . Because of radio frequency resource sharing, as described above, paging blocks 412 , 414 , 416 , and 418 , in this example, are lost due to collisions with paging blocks from SIM 1 network 130 . User equipment 100 may chose instead to receive paging blocks 402 , 404 , and 406 from SIM 1 network 130 . Following timing graph 500 from left to right and using one implementation of time tracking logic 122 , user equipment 100 receives paging block 402 . Using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 1 . Time tracking logic 122 uses timing error ê 1 and gain factor α 1 to determine the loop filter output c 1 . Time tracking logic 122 updates the differential adjustment factor, d 1 , subtracting the currently calculated loop filter output c 1 from the prior differential adjustment factor, d. Note that time tracking logic 122 subtracts c 1 from d 1 because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Time tracking logic 122 determines the timing adjustment, δ 1 , for the next scheduled paging block using the loop filter output c 1 . User equipment 100 may use timing adjustment, δ 1 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 404 . After user equipment 100 receives and processes paging block 402 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 2 , to predict the expected arrival of the next paging block 404 .
[0039] When user equipment 100 expects the next scheduled paging block 404 , user equipment wakes up from sleep mode to listen for paging block 404 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 2 . Time tracking logic 122 uses timing error ê 2 and gain factor α 1 to determine the loop filter output c 2 . Time tracking logic 122 updates the differential adjustment factor, d 2 , subtracting the currently calculated loop filter output c 2 from the prior differential adjustment factor, d 1 . Note that time tracking logic 122 subtracts c 2 from d 1 because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Time tracking logic 122 determines the timing adjustment, δ 2 , for the next scheduled paging block using the loop filter output c 2 . User equipment 100 may use timing adjustment, δ 2 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 406 . After user equipment 100 receives and processes paging block 404 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 2 , to predict the expected arrival of the next paging block 406 .
[0040] When user equipment 100 expects the next scheduled paging block 406 , user equipment wakes up from sleep mode to listen for paging block 406 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 3 . Time tracking logic 122 uses timing error ê 3 and gain factor α 1 to determine the loop filter output c 3 . Time tracking logic 122 updates the differential adjustment factor, d 3 , subtracting the currently calculated loop filter output c 3 from the prior differential adjustment factor, d 2 . Note that time tracking logic 122 subtracts c 3 from d 2 because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Because the timing adjustment, δ 3 , for the next scheduled paging block depends on whether the next scheduled paging block will be received on the same network or whether the paging block with be received from another network, the time tracking logic 122 may not determine the timing adjustment for the next paging block until user equipment 100 determines whether the next scheduled paging block will arrive from SIM 1 network 130 or SIM 2 network 132 .
[0041] FIG. 6 shows another example of how the user equipment 100 may use a similar series of paging blocks. Timing graph 600 includes a series of paging blocks from SIM 1 network 130 and SIM 2 network 132 that are scheduled for user equipment 100 . Because of radio frequency resource sharing, as described above, paging blocks 404 , 406 , and 412 , in this example, are lost due to collisions between paging blocks from SIM 1 network 130 and SIM 2 network 132 . User equipment 100 may chose instead to receive paging blocks 402 , 414 , 416 , and 418 . Following timing graph 600 from left to right and using one implementation of time tracking logic 122 , user equipment 100 receives paging block 402 . Using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 1 . Time tracking logic 122 uses timing error ê 1 and gain factor α 1 to determine the loop filter output c 1 . Time tracking logic 122 updates the differential adjustment factor, d 1 , subtracting the currently calculated loop filter output c 1 from the prior differential adjustment factor, d. Note that time tracking logic 122 subtracts c 1 from d because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Time tracking logic 122 determines the timing adjustment, δ 1 , for the next scheduled paging block using the loop filter output c 1 and adds the differential adjustment factor d 1 . Note that time tracking logic 122 adds d 1 because the currently received paging block 402 is from SIM 1 network 130 while the next scheduled paging block 414 is from SIM 2 network 132 . User equipment 100 may use timing adjustment, δ 1 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 414 . After user equipment 100 receives and processes paging block 402 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 1 , to predict the expected arrival of the next paging block 414 .
[0042] When user equipment 100 expects the next scheduled paging block 414 , user equipment wakes up from sleep mode to listen for paging block 414 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 2 . Time tracking logic 122 uses timing error ê 2 and gain factor α 1 to determine the loop filter output c 2 . Time tracking logic 122 updates the differential adjustment factor, d 2 , adding the currently calculated loop filter output c 2 and the prior differential adjustment factor, d 1 . Note that time tracking logic 122 adds c 2 and d 1 because user equipment 100 is currently listening to the network with network identification two (i.e., SIM 2 network 132 ). Time tracking logic 122 determines the timing adjustment, δ 2 , for the next scheduled paging block using the loop filter output c 2 . Note that time tracking logic 122 does not add or subtract d 2 because the currently received paging block 414 is from SIM 2 network 132 and the next scheduled paging block 416 is also from SIM 2 network 132 . User equipment 100 may use timing adjustment, δ 2 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 416 . After user equipment 100 receives and processes paging block 414 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 2 , to predict the expected arrival of the next paging block 416 .
[0043] When user equipment 100 expects the next scheduled paging block 416 , user equipment wakes up from sleep mode to listen for paging block 416 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 3 . Time tracking logic 122 uses timing error ê 3 and gain factor α 1 to determine the loop filter output c 3 . Time tracking logic 122 updates the differential adjustment factor, d 3 , adding the currently calculated loop filter output c 3 and the prior differential adjustment factor, d 2 . Note that time tracking logic 122 adds c 3 and d 2 because user equipment 100 is currently listening to network identification two (i.e., SIM 2 network 132 ). User equipment 100 may use timing adjustment, δ 3 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 418 . After user equipment 100 receives and processes paging block 416 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 3 , to predict the expected arrival of the next paging block 418 .
[0044] When user equipment 100 expects the next scheduled paging block 418 , user equipment wakes up from sleep mode to listen for paging block 418 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 4 . Time tracking logic 122 uses timing error ê 4 and gain factor α 1 to determine the loop filter output c 4 . Time tracking logic 122 updates the differential adjustment factor, d 4 , adding the currently calculated loop filter output c 4 and the prior differential adjustment factor, d 3 . Note that time tracking logic 122 adds c 4 and d 3 because user equipment 100 is currently listening to the network with network identification two (i.e., SIM 2 network 132 ). Because the timing adjustment, δ 4 , for the next scheduled paging block depends on whether the next scheduled paging block will be received on the same network or whether the paging block with be received from another network, the time tracking logic 122 may not determine the timing adjustment for the next paging block until user equipment 100 determines whether the next scheduled paging block will arrive from SIM 1 network 130 or SIM 2 network 132 .
[0045] FIG. 7 shows another example of how the user equipment 100 may use a similar series of paging blocks. Timing graph 700 includes a series of paging blocks from SIM 1 network 130 and SIM 2 network 132 that are scheduled for user equipment 100 . Because of radio frequency resource sharing, as described above, paging blocks 412 , 416 , and 418 , in this example, are lost due to paging blocks collisions between paging blocks from SIM 1 network 130 and SIM 2 network 132 . User equipment 100 may chose instead to receive paging blocks 402 , 414 , 404 , and 406 . Following timing graph 700 from left to right and using one implementation of time tracking logic 122 , user equipment 100 receives paging block 402 . Using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 1 . Time tracking logic 122 uses timing error ê 1 and gain factor α 1 to determine the loop filter output c 1 . Time tracking logic 122 updates the differential adjustment factor, d 1 , subtracting the currently calculated loop filter output c 1 from the prior differential adjustment factor, d. Note that time tracking logic 122 subtracts c 1 from d because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Time tracking logic 122 determines the timing adjustment, δ 1 , for the next scheduled paging block 414 using the loop filter output c 1 and adds the differential adjustment factor d 1 . Note that time tracking logic 122 adds d 1 because the currently received paging block 402 is from SIM 1 network 130 while the next scheduled paging block 414 is from SIM 2 network 132 . User equipment 100 may use timing adjustment, δ 1 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 414 . After user equipment 100 receives and processes paging block 402 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 1 , to predict the expected arrival of the next paging block 414 .
[0046] When user equipment 100 expects the next scheduled paging block 414 , user equipment wakes up from sleep mode to listen for paging block 414 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 2 . Time tracking logic 122 uses timing error ê 2 and gain factor α 1 to determine the loop filter output c 2 . Time tracking logic 122 updates the differential adjustment factor, d 2 , adds the currently calculated loop filter output c 2 and the prior differential adjustment factor, d 1 . Note that time tracking logic 122 adds c 2 and d 1 because user equipment 100 is currently listening to the network with network identification two (i.e., SIM 2 network 132 ). Time tracking logic 122 determines the timing adjustment, δ 2 , for the next scheduled paging block using the loop filter output c 2 and subtracts the differential adjustment factor d 2 . Note that time tracking logic 122 subtracts d 2 because the currently received paging block 414 is from SIM 2 network 132 while the next scheduled paging block 404 is from SIM 1 network 130 . User equipment 100 may use timing adjustment, δ 2 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 404 . After user equipment 100 receives and processes paging block 414 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 2 , to predict the expected arrival of the next paging block 404 .
[0047] When user equipment 100 expects the next scheduled paging block 404 , user equipment wakes up from sleep mode to listen for paging block 404 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 3 . Time tracking logic 122 uses timing error ê 3 and gain factor α 1 to determine the loop filter output c 3 . Time tracking logic 122 updates the differential adjustment factor, d 3 , subtracting the currently calculated loop filter output c 3 from the prior differential adjustment factor, d 2 . Note that time tracking logic 122 subtracts c 3 from d 2 because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Time tracking logic 122 determines the timing adjustment, δ 3 , for the next scheduled paging block using the loop filter output c 3 . Note that time tracking logic 122 does not add or subtract d 3 because the currently received paging block 404 is from SIM 1 network 130 and the next scheduled paging block 406 is also from SIM 1 network 130 . User equipment 100 may use timing adjustment, δ 3 , as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block 406 . After user equipment 100 receives and processes paging block 404 , it may enter a sleep mode until the next paging block is scheduled to arrive. While in sleep mode, user equipment 100 may use its internal time base 140 along with timing adjustment, δ 3 , to predict the expected arrival of the next paging block 406 .
[0048] When user equipment 100 expects the next scheduled paging block 406 , user equipment wakes up from sleep mode to listen for paging block 406 . Again, using the midamble of the burst, user equipment 100 determines the timing error between the expected arrival of the midamble and the actual arrival of the midamble of the burst, labeled ê 4 . Time tracking logic 122 uses timing error ê 4 and gain factor α 1 to determine the loop filter output c 4 . Time tracking logic 122 updates the differential adjustment factor, d 4 , subtracting the currently calculated loop filter output c 4 from the prior differential adjustment factor, d 3 . Note that time tracking logic 122 subtracts c 4 from d 3 because user equipment 100 is currently listening to the network with network identification one (i.e., SIM 1 network 130 ). Because the timing adjustment, δ 4 , for the next scheduled paging block depends on whether the next scheduled paging block will be received on the same network or whether the paging block with be received from another network, the time tracking logic 122 may not determine the timing adjustment for the next paging block until user equipment 100 determines whether the next scheduled paging block will arrive from SIM 1 network 130 or SIM 2 network 132 .
[0049] As shown through FIGS. 6-8 , time tracking logic 122 may use paging blocks from either SIM 1 network 130 or SIM 2 network 132 to compensate for the phase timing error of the internal time base 140 , even if the paging blocks collide. In some implementations, the time tracking logic 122 may also compensate for the frequency timing error due to the frequency drift of the internal time base. The frequency timing error may be used in addition to the phase timing error to compensate the internal time base when user equipment 100 predicts the arrival of the next paging block.
[0050] In such an implementation, example time tracking parameters 128 may include:
[0000]
TABLE 3
Parameter
Variable
Type
Description
α 1
constant
Gain of the first order phase locked loop.
This constant may be used to stabilize the
loop and may be set to a rational number
less than one
α d
constant
Gain of the “delta loop.” This constant
may be used to stabilize the loop and may
be set to a rational number less than one
α p
constant
Gain of internal time base drift. This
constant may be used to stabilize the
updates to the internal time base drift
and may be set to a rational number less
than one
L
constant
Length (in time) of the averaging window
used in estimating the internal time base
drift
n
index
An index representing receipt of the current
paging block; n + 1 is the next scheduled
paging block
i(n)
input
Network Identification (e.g., SIM1 network
or SIM2 network) for the n-th paging block
ê(n)
input
The measured timing error from the n-th
paging block
Δ s (n)
input
Time since last paging block was received
c
internal state
First order loop filter output
variable
d
internal state
The differential adjustment applied when
variable
the next scheduled paging block is from a
different network
{circumflex over (p)} s
internal state
Estimated drift rate of the internal time
variable
base (in Hertz)
δ
internal
Timing adjustment between the previous
variable
paging block and the current paging block
S Δ, i i = 1, 2
internal state
Cumulative counts of the internal time
variable
base
S δ, i i = 1, 2
internal state
Cumulative timing adjustments
variable
q
output
Time base adjustment for the next paging
block
[0051] Using the time tracking parameters 128 listed above, the time tracking logic 122 may implement the following algorithm:
[0000]
TABLE 4
for n = 1,2, ...
% calculate loop filter output (phase error timing adjustment)
c = α 1 ê(n);
% update differential adjustment
d = d + (−1) i(n) α d c;
% determine time base adjustment based on phase timing error
if
i(n + 1) == i(n)
then δ = c ;
elseif
i(n + 1) == 1
then δ = c − d;
elseif
i(n + 1) == 2
then δ = c + d;
end
% determine time base adjustment based on phase timing error
% and timing error due to frequency drift of the internal time base
q = δ + Δ s (n) {circumflex over (p)} s
% update frequency timing offset parameters
S Δ,1 = S Δ,1 + Δ s (n) ;
S Δ,2 = S Δ,2 + Δ s (n);
S δ,1 = S δ,1 + δ;
S δ,2 = S δ,2 + δ;
if
S Δ,i(n) > L
then
% estimate internal time base frequency drift
{circumflex over (p)} s = {circumflex over (p)} s + α p S δ,i(n) (n)/L ;
S Δ,i(n) = 0 ;
S δ,i = 0;
end
end
[0052] In one implementation using the above parameters and algorithm, time tracking logic 122 , in addition to determining the time base adjustment due to phase timing error, time tracking logic 122 may include an adjustment due to the frequency drift of the internal time base. Time tracking logic 122 may estimate the time base adjustment due to the frequency drift of the internal time base by multiplying the estimated internal time base frequency drift, {circumflex over (p)} s , by the time elapsed since the last paging block was received, Δ s (n). The internal time base frequency drift, {circumflex over (p)} s , may be estimated over a series of paging blocks using an averaging window, L. Time tracking logic 122 accumulates the actual time elapsed, S Δ , between reception of paging blocks and accumulates the accumulated phase timing error, S δ . Each time the actual time elapsed, S Δ , exceeds the length of the averaging window, L, the time tracking logic 122 may update the estimated internal time base frequency drift, {circumflex over (p)} s . Time tracking logic 122 may update the estimated internal time base frequency drift, {circumflex over (p)} s , by the estimated frequency error, calculated by a gain constant, α p , multiplied by the accumulated phase timing error, S δ , divided by the length of the averaging window, L. In addition, the time tracking logic 122 may accumulate the actual time elapsed between reception of paging blocks and accumulate the accumulated phase timing error for each SIM independently.
[0053] FIGS. 8-10 are similar in aspects to FIGS. 5-7 . As discussed above, the time tracking logic 122 may use paging blocks from either SIM 1 network 130 or SIM 2 network 132 to compensate for the phase timing error of the internal time base 140 , even if the paging blocks collide, and even if the paging blocks arrive from different SIM networks. For each reception of the paging block, time tracking logic 122 may calculate, ê, c, d, and δ in the same way as described above for FIGS. 5-7 . However, rather than using δ as the compensation factor to apply to internal time base 140 for predicting the expected arrival of the next paging block, the time tracking logic 122 may use timing compensation q, as shown in FIGS. 8-10 . Timing compensation q includes the compensation factor for the phase timing error and differential offset, δ, as described above, and an additional compensation factor for the timing error from the frequency drift Δ s (n) {circumflex over (p)} s of the internal time base.
[0054] FIG. 11 shows flow diagram 1100 and is one implementation of the time tracking logic 122 . User equipment 100 receives a paging block on SIM 1 network 130 or SIM 2 network 132 ( 1102 ) and processes the paging block to determine the timing error, ê(n), between the expected arrival of the paging block and the actual arrival of the paging block ( 1104 ). Next, time tracking logic 122 determines whether the current network is SIM 1 network 130 or SIM 2 network 132 ( 1106 ). If the current network is SIM 1 network 130 , timing differential, d, is updated by subtracting the loop output, c=α 1 ê(n), from the prior timing differential ( 1108 ). If the current network is SIM 2 network 132 , timing differential, d, is updated by adding the loop output, c=α 1 ê(n), and the prior timing differential ( 1110 ).
[0055] Next, the time tracking logic 122 determines which SIM network will receive the next paging block ( 1112 ). At block 1114 , if the next paging block is on the same network, the timing offset is determined using option 1 ( 1118 ). If the time tracking logic 122 uses option 1 , the timing offset is set to the phase timing error from the loop output, δ=c=α 1 ê(n), and does not account for the timing differential, d. On the other hand if, at block 1116 , the next paging block switches from SIM 2 to SIM 1 , then the timing offset is determined using option 2 ( 1120 ). If the time tracking logic 122 uses option 2 , the timing offset is set to the phase timing error from the loop output and subtracts the timing differential, d, between SIM 2 and SIM 1 . Thus, δ=c−α d d. On the other hand if, at block 1116 , the next paging block switches from SIM 1 to SIM 2 , then the timing offset is determined using option 3 ( 1122 ). If the time tracking logic 122 uses option 3 , the timing offset is set to the phase timing error from the loop output and adds the timing differential, d, between SIM 1 and SIM 2 . Thus, δ=c+α d d.
[0056] Next, the time tracking logic 122 determines the time base adjustment, q, which takes into account the phase timing error, the timing differential, and the frequency timing offset ( 1124 ). q=δ+Δ s (n){circumflex over (p)} s . User equipment 100 may use q as the compensation factor for adjusting the internal time base 140 when predicting the timing of the next scheduled paging block. Next, time tracking logic 122 accumulates the actual time elapsed, S Δ , between reception of paging blocks and accumulates the accumulated phase timing error, S δ ( 1126 ). At block 1128 , time tracking logic 122 determines whether the actual time elapsed, S Δ , exceeds the length of the averaging window, L. If the actual time elapsed, S Δ , exceeds the length of the averaging window, L, the time tracking logic 122 may update the estimated internal time base frequency drift, {circumflex over (p)} s ( 1130 ). In block 1132 , the time tracking logic 122 determines whether to continue listening for the next paging block.
[0057] The methods, devices, techniques, and logic described above may be implemented in many different ways in many different combinations of hardware, software or both hardware and software. For example, all or parts of the system may include circuitry in a controller, a microprocessor, or an application specific integrated circuit (ASIC), or may be implemented with discrete logic or components, or a combination of other types of analog or digital circuitry, combined on a single integrated circuit or distributed among multiple integrated circuits. All or part of the logic described above may be implemented as instructions for execution by a processor, controller, or other processing device and may be stored in a tangible or non-transitory machine-readable or computer-readable medium such as flash memory, random access memory (RAM) or read only memory (ROM), erasable programmable read only memory (EPROM) or other machine-readable medium such as a compact disc read only memory (CDROM), or magnetic or optical disk. Thus, a product, such as a computer program product, may include a storage medium and computer readable instructions stored on the medium, which when executed in an endpoint, computer system, or other device, cause the device to perform operations according to any of the description above.
[0058] The processing capability of the system may be distributed among multiple system components, such as among multiple processors and memories, optionally including multiple distributed processing systems. Parameters, databases, and other data structures may be separately stored and managed, may be incorporated into a single memory or database, may be logically and physically organized in many different ways, and may implemented in many ways, including data structures such as linked lists, hash tables, or implicit storage mechanisms. Programs may be parts (e.g., subroutines) of a single program, separate programs, distributed across several memories and processors, or implemented in many different ways, such as in a library, such as a shared library (e.g., a dynamic link library (DLL)). The DLL, for example, may store code that performs any of the system processing described above. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.
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A technique for time tracking helps a mobile communication device with multiple SIMs to more accurately maintain synchronization with a base station. By utilizing synchronization information from both SIMs, the technique is able to more frequently and more accurately adjust timing information for each SIM. As a result, the mobile communication device exhibits an increased ability to accurately synchronize without the need for a higher precision reference or increased power consumption.
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This application claims benefit of application Ser. No. 60/190,778 filed Mar. 20, 2000.
FIELD OF THE INVENTION
The present invention relates generally to processes for the preparation of parylene dimers, and more particularly to processes for the preparation of derivatives of octafluoro-[2,2]paracylophane, otherwise known as AF4.
BACKGROUND AND SUMMARY OF THE INVENTION
Parylene is a generic term used to describe a class of poly-p-xylylenes which are derived from a dimer having the structure:
wherein X is typically a hydrogen, or a halogen. The most commonly used forms of parylene dimers include the following:
Parylene coatings are obtained from parylene dimers by means of a well-known vapor deposition process in which the dimer is vaporized, pyrolized, i.e. cleaved into a monomer vapor for, and fed to a vacuum chamber wherein the monomer molecules polymerize, and deposit onto a substrate disposed within the vacuum chamber.
Due to their ability to provide thin films and conform to substrates of varied geometric shapes, parylene materials are ideally suited for use as a conformal coating in a wide variety of fields, such as for example, in the electronics, automotive, and medical industries.
Parylene polymers are usually formed by chemical vapor deposition (CVD) processes. One such process is the Gorham process in which a parylene dimer having the molecular structure:
is vaporized and the dimer bonds are then cleaved to yield parylene monomers. The parylene monomers are deposited onto a surface and subsequently polymerized. Because the dielectric constant and melting temperature of parylene polymers usually increases as the number of fluorine atoms within the polymer increases, it is desirable to use octafluoro-[2,2]paracylcophane (AF4).
Octafluoro-[2,2]paracyclophane, more precisely 1,1,2,2,9,9,10,10-Octafluoro-[2,2]paracyclophane, and more commonly referred to in the industry as AF4, is a fluorine substituted version of the above-noted dimers and has the structure:
It is known that parylene coatings (Parylene AF 4 ) which are derived from the AF 4 dimer by the vapor deposition process have a very high melting temperature (about 540° C.), and a low dielectric constant (about 2.3). These characteristics make Parylene AF 4 ideally suited for many high temperature applications, including electronic applications, and potentially as an inter-layer dielectric material for the production of semiconductor chips. However, up to the present time, AF4, which is used as the dimer starting material for depositing Parylene F coatings, has been commercially unavailable due to high costs of production. Both OFP and AF4 are used interchangeably herein and are intended to refer to the same compound.
One known method of producing AF4 is described in U.S. Pat. No. 5,210,341 wherein the process of preparing AF4 utilizes a low temperature in conjunction with a reduced form of titanium in order to produce dimerization of dihalide monomers. One aspect of the '341 patent provides a process for preparing octafluoro-[2,2]paracyclophane, which comprises contacting a dihalo-tetrafluoro-p-xylylene with an effective amount of a reducing agent comprising a reduced form of titanium and an organic solvent at conditions effective to promote the formation of a reaction product comprising octafluoro-[2,2]paracyclophane.
While the process described in the '341 patent is effective for its intended purpose, it has been found that the process is still too expensive for commercial realization due to low yields, that there are some impurities in the AF4 dimer, and furthermore that it would be difficult to adapt to a large scale commercial production.
TFPX-dichloride having the following structure:
is another preferred starting material for the preparation of AF4. Heretofore, the only useful preparation of TFPX-dichloride has been via a high yield, photo-induced chlorination of α,α,α′,α′-tetrafluoro-p-xylene (hereinafter “TFPX”) having the molecular structure:
The conventional procedure for synthesizing TFPX involves the fluorination of terephthaldehyde, which has the molecular structure:
SF 4 and MoF 6 are the most commonly used reagents for terephFthaldehyde fluorination. However, SF 4 and MoF 6 are expensive, reducing the industrial utility of this synthetic scheme. In addition, SF 4 and MoF 6 are toxic materials, so a large amount of hazardous waste is produced using these reagents.
Russian patent 2,032,654 discloses an alternative method of synthesizing TFPX in which α,α,α′,α′-tetrabromo-p-xylene (hereinafter “TBPX”) having the molecular structure:
is reacted with SbF 3 to produce TFPX. This method employs the well established electrophilic catalyzed S N 1 reaction mechanism for replacement of benzylic halogen atoms of the TFPX with fluorine atoms. According to this method, the anitmony in SbF 3 acts as an elctrophile which removes bromine from TBPX to form a carbocation. The carbocation subsequently reacts with fluorine to form TFPX. While this reaction is reported to provide good yield when carried out under comparatively mild reaction conditions, antimony containing compounds are highly toxic and explosive. Furthermore, the SbF 3 is used in a stoichiometric amount rather than a catalytic amount, resulting in large quantities of hazardous waste materials. This method of synthesizing TFPX thus has limited use for industrial applications.
AF4 is a member of the class of paracyclopenones. Paracyclophenone (PCP) chemistry has grown considerably since the isolation of the parent compound in 1949. Braun et al., NATURE (1949) 164, 915. Besides finding commercial application as monomers for the parylene type polymers, these molecules have spawned an unusual and unique chemistry. The close proximity of the face-to-face aromatic rings, coupled with the rigid skeleton and high strain energy translates into such effects as trans-annular interactions, thermal racemization and isomerism, surprising directing effects in multiple electrophilic substitution and unusual spectroscopic phenomena. The use of ring-substituted [2,2] PCP skeletons as chiral backbones is of considerable current interest. Highly fluorinated cyclophanes on the other hand, have received much less attention, even though these compounds have desirable industrial properties and should at least display as equally rich a chemistry as their hydrocarbon counterparts. This imbalance is being redressed following the syntheses of the bridge fluorinated cyle 1,1,2,2,9,9,10,10 octafluoro[2,2]paracyclophane (abbreviated as OFP, and more commonly referred to in the industry as AF4) that have been reported previously.
Two complementary synthetic methods for the introduction of two substituents into the rings of octaflouroparayclophane have thus been developed. Nitration gives three isomers with the nitro functionalities in different rings, oriented pseudo meta, pseudo para and pseudo ortho. Bromination on the other hand gives a dibromide where both halogens are in the same ring, para to each other. All such products serve as versatile starting materials for the preparation of a variety of novel homo- and hetero-annular disubstitututed OFP derivatives. The compounds synthesized have also been found to be precursors of a variety of other disubstituted OFP derivatives. The synthesis, characterization and thermal isomerization of a variety of both homo- and hetero-annularly disubstituted OFP derivatives has also been developed and described.
The instant invention provides improved processes for the preparation of octafluoro-[2,2]paracyclophane which involve contacting a OFP with dry nitrogen, nitronium tetrafluoroborate dissolved in sulphophane to provide pseudo meta-, pseudo para-, and pseudo ortho-dinitro-1,1,2,2,9,9,10,10-octafluoroparacyclophanes. Reduction of these three products using iron powder/concentrated hydrochloric acid provided the corresponding diamino products in good isolated yields. The three diamino products proved to be versatile starting materials for further transformations by reacting with an aqueous solution of copper (I) bromide and hydrobromic acid or an aqueous solution of potassium iodide to provide three isomeric dibromo and diiodo-OFP derivatives in good yield.
Accordingly, among the objects of the instant invention are: the provision of improved processes for the preparation of octafluoro-[2,2]paracyclophane; and more specifically, the provision of improved processes for the preparation of octafluoro-[2,2]paracyclophane from novel OFP precursor derivatives.
Other objects, features and advantages of the invention shall become apparent as the detailed description thereof proceeds.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to highly thermally stable derivatives and precursors of octafluoro[2,2]paracyclophenone (AF4) and their preparation.
The nitration of AF4 gives a mononitro product in high yield. However, when such nitration is carried out under the more forcing conditions of five equivalents of NO 2 BF 4 and a temperature of 80° C. (step i), the products generated are observed to be a mixture of three isomeric dinitro derivatives in over 80% combined isolated yield, with the ratio of the isomers being 1:1:1.
One of the isomers could be separated from the other two by column chromatography since it displayed a lower R f value than the other two, which co-eluted. The quicker running mixture of the two isomers could be enriched in one or the other isomer by fractional crystallization or sublimation. The 19 F NMR spectrum of each isomer showed only 2 AB patterns. The 19 F NMR spectra of AF4 consists of a singlet, and that mononitro-AF4 appears as 4 AB patterns. The increase in the symmetry of these new products relative to mono-nitro-AF4 indicated incorporation of at least two nitro groups.
Mass spectrometry confirmed not only that the products did indeed contain two nitro groups, but also that they were located on different rings. The relative orientation of the nitro groups in each of the three isomers was established through 1 H NMR, and further confirmed by thermal isomerizations and correlation of their physical properties with those already established for hetero-annularly disubstituted [2,2] PCP derivatives. The products were identified as pseudo-meta-, pseudo-para- and pseudo-ortho-dinitrooctafluoroparacyclophanes 2a-c, as illustrated in Scheme 1. No evidence of the pseudo-geminal isomer was observed, although as little as 1% could have been detected.
The introduction of a nitro functionality into one ring deactivates that ring to further electrophilic substitution and guides subsequent reaction to the other unsbubstituted ring. The lack of a pseudo geminal isomer is somewhat surprising since there are many examples of complete (or predominant) pseudo geminal electrophilic aromatic substitutions promoted by the substituents bearing basic functionalities, through their participation as intramolecular bases. Nitrations, however, are known to be less susceptible to such kinetic effects, in comparison to brominations, for example. The inventors have proposed that the lack of such a dinitro isomer in this reaction is due to steric effect. The nitration of the hydrocarbon [2,2] PCP using nitric acid at 75° C. is reported to yield mononitro [2,2] PCP (26%), and pseudo-meta (2%), pseudo-para (2%), pseudo-ortho (1.4%) and pseudo-geminal (0.7%) dinitro isomers.
The inventors have previously demonstrated that nitro-AF4 provides a route to a variety of ring substituted AF4 derivatives and similar synthetic methodologies can be applied here that allow the generation of a number or inter-annularly disubstituted AF4. See Roche et al., J. ORG. CHEM. 1999, 64, 9137.
The reactions in Scheme 1 were all performed on both single isomers and mixtures of the three isomers. The pseudo ortho isomer could always be separated from the pseudo meta/pseudo para mixture by column chromatography, regardless of the substituents. The pseudo meta/pseudo para isomers were, in general, unable to be separated by column chromatography. All reaction yields were essentially the same whether preformed on single or multiple isomers, and are comparable to the corresponding reactions used to make the monosubstituted AF4 analogues. The only difference in reactivity for the three disubstituted isomers in the reactions in Scheme 1 was observed in their trifluoromethylation reactions, where pseudo ortho duiodo isomer gave lower conversions and slower reactions. No isomerism or loss of integrity of the AF4 skeleton was observed during any of these reactions, although deliberate high temperature isomerization of selected examples of these compounds was studied.
The reduction of 2a-c using iron powder/conc. hydrochloric acid (step ii) gave the corresponding diamino products 3a-c in good isolated yields (82-84%). Cyclophanes containing electron donating substituents in one ring and electron acceptors in the other ring are often reported to be colored, and the corresponding inter-annular nitro-amino systems for the hydrocarbon [2,2] PCP vary from yellow to red, depending on the relative orientation of the two substituents. In an attempt to generate 6 (Scheme 2) with an amino group in one ring and a nitro group in the other, the milder reducing agent of cyclohexene and Pd on carbon was used in conjunction with 2c. Besides the corresponding diamino AF4 3c (38%), the nitroamino derivative 6 (11%) was isolated, and the hydroxyl-amino product 7 (15%).
Dissapointingly, 6 was a white solid, in contrast to the orange/yellow color of the corresponding [2,2] PCP compound. This difference can be attributed to the electron density from the interacting 7 systems by the electron withdrawing fluoroalkyl bridging units, thus reducing charge transfer.
The diamino AF4 isomers 3a-c proved to be versatile starting materials for further transformations, with the most straightforward being the formation of the respective N-acetyl and -triflouroacetyl-amides in high isolated yield (84-97%). These compounds proved not only useful for characterization purposes, but also as protecting groups which moderated the reactivity of the diamino AF4 systems, and thus made appropriate materials for the high temperature thermal isomserization studies described infra herein.
The double diazotization of these diamino-systems proved as successful diazotization of monoamino-AF4, and thus the three isomeric dibromo (5a-c) and diiodo-AF4 (4a-c) derivatives were prepared in good isolated yield (60-78%) via Sandmeyer type chemistry (steps iii, iv, v in Scheme 1). The hetero-annular dibromides proved useful for comparison purposes when a homo-annular dibromide was later prepared. The hetero-annular dibromides also served as useful intermediates for further transformations, although the diiodes generally gave higher yields in such reactions, and were therefore the more desirable starting materials.
Triflouromethylation of the pseudo meta and pseudo para AF4 diiodides 4a,b gave moderate yields of corresponding bis(triflouromethylated) products 8a,b (50%) (Scheme 3), along with appreciable amounts of monotrifluoromethylated product 10 (30%) (Scheme 4). It was also observed that the addition of palladium dichloride provided vast improvements in the yields of bis(triflouromethylated) products (80%), and a consequent decrease in chemically reduced side products (Scheme 4).
When a typical uncatalyzed triflouromethylation was performed on pseudo ortho AF4 diiodide 4c (Scheme 4), the only two products obtained besides starting materials were identified as 10 (33%) and pseudo ortho iodo-triflouromethyl OFP 9 (21%). However, the addition of PdCl 2 promoted a superior reaction with the pseudo ortho bis(trifluoromethyl) derivative, 8c, being isolated in 68% yield, along with a 10% yield of iodo-triflouromethyl derivative, 9, which could itself be reduced by zinc in acetic acid to form triflouromethyl-AF4 (91%).
The difference in reactivity displayed by the isomeric diiodides can be best understood in terms of the iodides simply being located either on the same or different sides of the cyclophane. Although exchange of triflouromethyl for iodine should make the iodo-triflouromethyl intermediate compounds more reactive toward further substitution, clearly this is not the case for the pseudo ortho isomer. It is likely that the two reaction centers in the pseudo ortho isomers are so close that when one iodine is replaced by a trifluoromethyl group, there is sufficient steric and electronic shielding by the attached trifluoromethyl group to inhibit further substitution. Having observed through space NMR interaction between syn bridging flourines and a triflouromethyl substituent on the ring, the inventors believe that these syn bridge fluorines also provide steric and electrostatic shielding to an attacking nucleophile. The use of a relatively large transition metal catalyst like Pd(III) may serve to reduce such steric constraints on the incoming nucleophile by coordinating the substrate and the nucleophile before joining them through a reductive elimination, thus resulting in the superior observed yields of triflouromethylyated products in PdCl 2 catalyzed reactions.
The pseudo ortho diiodide 4c was also used to produce the corresponding diphenyl derivative via reaction with phenyl magnesium bromide and PdCl 2 , providing the diphenyl derivative in 21% yield along with 20% monophenyl-AF4. Identical mono and diphenylated products were also obtained via diazonium chemistry and benzene.
Although the overall yields of the diiodides and dibromides were acceptable for a three step procedure (40-53% isolated from AF4) as in Scheme 1, a direct bromination procedure to dibrominate OFP would be much more desirable. To this end, AF4 was subjected to several known bromination methods. However, the only method that was successful in generating more than a trace of dibromo-AF4 was a method recently reported by the inventors for bromination of deactivated aromatics. See Duan et al., SYNLETT (1999), 1245.
When triflouroacetic acid solution of AF4 was exposed to a combination of four equivalents of NBS and sulfuric acid at 80° C., a single major product was produced. The presence of 2AB patterns in the 19 F NMR of this compound led to the belief that the product was a dibromide. The isolated yield of this compound, after column chromatography, was 55%m and somewhat surprisingly, the NMR of the product did not match any of those of the three inter-annular dibromides that had been prepared via the nitration/reduction/diazonium chemistry described hereinabove. Mass spectrometry revealed that the product was indeed a dibromide isomer, but that the bromines were both on the same ring. This information, coupled with the 1 H and 19 F NMR patterns (described infra.) indicated that this was para dibromo AF4, 5d.
A bromine susbtituent is normally viewed as a deactivating and ortho/para directing substituent in electrophilic aromatic substitution, and usually a deactivating substituent would guide subsequent substitution into the other ring of a [2,2] PCP. This was not, however, the case for this reaction, although the second bromine did enter para to the first.
With p-dibromo AF4 (5d) in hand, it was then possible to prepare the p-bis(triflouoromethyl) AF4 derivative, 8d, (Scheme 5) albeit in lower yields than had been obtained for the hetero-annular diiodides, 4c. As expected, the NMR spectra of 8d were also distinctively different from those of 8a, 8b, and 8c.
Thermal Isomerizations
The [2,2] PCP skeleton is rigid, and under normal conditions, maintains its integrity allowing, for example, the application of [2,2] PCP derivatives as chiral ligands and molecular scaffolds of known fixed geometry. 5 This holds true for temperatures below 150-200° C. Above these temperatures, ring substituted [2,2] PCP derivatives exhibit a thermal isomerization which is unique to this system. Typically, the deliberate isomerizations have been performed without solvent at 200° C. for 24 hours. It has been demonstrated that they proceeded though a bibenzyl type diradical intermediate. Reich et al., AM. CHEM. SOC. (1969) 91, 3517.
One might expect the longer C—C bridge length in OFP (1.577 Å) relative to [2,2] PCP (1.569 Å) to allow the racemization of AF4 derivatives to occur at lower temperatures since it is this bond that must break and reform. Conversely, since replacement of hydrogen by fluorine in saturated systems usually increases thermal and chemical stability, coupled with the lower stability of difluorobenzyl radicals relative to benzyl radicals, OFP derivatives might be predicted to require much higher temperatures to undergo such isomerizations. The inventors were therefore interested to determine whether OFP derivatives would undergo such thermal isomenzations, and if so, what temperatures would be required.
Initially the pseudo ortho dibromo-, pseudo ortho diamino- and dinitro-OFP derivatives were examined, but these compounds proved to be perfectly stable and unchanged when heated neat at 200° C. for 12 hours. After 8 hours at 300° C., the diamino compound had fully decomposed, whilst the dibromo and dinitro compounds showed no isomerization. When the temperature was raised to 350° C. the dinitro compound was extensively charred, but showed traces of isomerization to its pseudo para counterpart, whereas the dibromide was also charred but showed no isomerizations. In contrast, heating the pseudo ortho bis(trifluoroaceamido) AF4 led to no charring, and the sample showed traces of isomerization to its pseudo para isomer.
Therefore, the pseudo ortho bis(trifluoroacetamnido)-OFP was heated to 381-390° C. for 2 hours, and was shown by NMR analysis to have converted to a 5:1 ratio of pseudo ortho and pseudo para isomers. Encouraged by this result, this mixture was further heated at 350-360° C. for 24 hrs and the ratio of isomers was found to have changed to 1:7 in favor of the less sterically congested pseudo para isomer. The mass recovery was 75%, with the balance presumably being insoluble polymeric material. Therefore the bridging fluorine atoms in OFP appear to impart 150° C. more kinetic thermal stability to a [2,2] PCP ring system. This not only demonstrates the stabilizing effect of exchanging fluorine for hydrogen, but has serious implications in the use of these fluorinated phanes as chiral ligands, catalysts and auxiliaries, since they display far superior resistance to thermal isomerization than the hydrocarbon analogues, and could therefore be employed at higher temperatures without losing their chirality through thermal racemization.
Characterization
The introduction of a second substituent onto a ring in a [2,2] PCP system can give rise to 7 possible isomers, of which 3 are racemic and 4 are meso (if the two substituents are equivalent). There has been substantial work in this area, and numerous strategies and techniques have evolved that allow unambiguous isomer and structure determination in hydrocarbon [2,2] PCP systems, with 1 H NMR and mass spectrometry comprising the most powerful tools. Previously the inventors reported that not only were these strategies and techniques equally applicable to the characterization of mono substituted OFP derivatives, but that the OFP derivatives also offered the added bonus of 19 F NMR to distinguish between products. Roche et al., J. ORG. CHEM. (1999) 64, 9137. The inventors have demonstrated that the 1 H Substituent Chemical Shift (SCS) values previously derived for the amino-OFP system allow accurate prediction of the 1 H shifts of the three new diamino-OFP products synthesized in accordance with the present invention, and also that the 19 F NMR shifts of the bis(trifluoromethylated) OFP compounds (both hetero- and homo-annular) can also be predicted via the use of the 19 F SCS values derived from monotrifluoromethylated OFP.
Heretobefore, the calculation of 19 F SCS values, and the first demonstration that they may be used to predict the shifts of the bridging fluorines in multiply-substituted OFP derivatives has not been reported.
1 H NMR
Due to their symmetric nature, hetero-annularly identically disubstituted [2,2] PCP's display a simple and characteristic 1 H NMR pattern consisting of one singlet and one AB pattern. All of the disubstituted OFP products described herein also display this feature. The pseudo ortho disubstituted isomer is generally the easiest to recognize since any “gem shift” operates upon the resonance which is a singlet, forcing it downfield, normally clear of the other resonances.
Since it has been demonstrated that amino substituted [2,2] PCP's are the most convenient for NMR investigation, the inventors earlier derived the SCS values for the amino-OFP system (Table 1). Prior work in hydrocarbon [2,2] PCP systems has amply shown that these SCS values are additive, and therefore may be used to calculate proton shifts for multiply substituted systems. The observed 1H shifts can be compared for the three diamino-OFP isomers of the present invention, with those shifts calculated from the SCS values previously dereived (Table 2).
TABLE 1
Amino OFP SCS values
O
m
p
m′
p′
0′
gem
−1.21
0.36
−0.76
−0.20
0.01
−0.12
+0.69
(Where o = ortho, p = para, m = meta, m′ = pseudo meta, p′ = pseudo para, o′ = pseudo ortho and gem = pseudo geminal).
TABLE 2
Predicted ‘H Chemical Shifis using Amino OFP SCS Values
Compound
Peak Type
SCS Effects
Calculated/ppm
Observed/ppm
Pseudo meta
singlet
o + p′
6.10
6.08
DiNH 2
A
m + gem
7.63
7.57
3a
B
p + o′
6.42
6.44
Pseudo para
singlet
o + m′
5.89
6.00
diNH 2
A
m −o′
6.82
6.87
3b
B
p + gem
7.23
7.04
pseudo ortho
singlet
o + gem
6.78
6.89
diNH 2
A
m + p′
6.95
7.00
3c
B
p + m′
6.34
6.36
It is clear that there is good agreement between the predicted and observed chemical shifts.
19 F NMR
Mono-functionalised OFP derivatives exhibit a characteristic four AB pattern in their 19 F NMR spectra, whereas inter-annular identically disubstituted OFP derivatives contain only four different bridging fluorine atoms, which manifest themselves as two A-B patterns. (This is also true for para and ortho oriented intra-annular substituted OFP derivatives). All of the disubstituted OFP derivatives described herein display only two AB patterns in their 19 F NIMR spectra. (Of course, OFP derivatives bearing two different substituents have eight different bridge fluorines that appear as four A-B's, similar to a mono OFP product).
The problem previously described concerning the assignment of fluorine resonances to specific fluorine atoms still exists for the derivatives described here except for the four bis(trifluoromethyl)-OFP derivatives. The “through space” coupling that occurs between a trifluoromethyl ring substituent and the proximate syn bridging fluorines 10 allowed the instant recognition of those bridge fluorines since they appear as quartets. Their partners in the respective A-B patterns could be located by line shape and coupling constant. Thus F 1s /F 1a , F 2s ,/F 2a for trifluoromethyl-OFP could be assigned, although the assignment of the remaining 4 fluorines was ambiguous.
However, because of symmetry in the bis(trifluoromethyl)-OFP derivatives 8a-d, we can use this coupling interaction to fully assign, for the first time, the bridge fluorine resonances of these systems (and further confirm the accuracy of our isomer assignments). The strategy was to first identify the resonances split in to the large and small quartets, and then find their AB partners. Easiest to identify was the pseudo meta isomer, since this is the only isomer to contain both quartet resonances within the same AB. (This also has the unfortunate consequence that the other two fluorines for this isomer cannot be assigned unambiguously). For the other isomers, the resonances with the larger and smaller quartets were assigned F 2s and F 1s respectively. Identification of their AB partners via line shape and coupling constant gave F 2a and F 1a . Thus, for the first time, all the fluorine atoms could be assigned to their fluorine resonances.
This presented a situation where there were 19 F chemical shifts and assignments for four disubstituted OFP derivatives, and assignments for half of the shifts for the corresponding monosubstituted derivative. Since it has been demonstrated that 1 H SCS values are additive for the OFP system, it was projected that the 19 F SCS values should be too, and therefore we should be able to work backwards and assign the remaining four fluorine shifts for the mono derivative. Indeed, one set of assignments for the remaining four fluorines gave much better agreement than the others, as predicted from SCS values taken from the disubstituted systems. These assignments were therefore used in the calculation of the 19 F SCS values for the monotrifluoromethyl OFP system 10.
TABLE 3
19 F SCS values for 10, in ppm
F 1a
F 1s
F 2a
F 2s
F 3a
F 3s
F 4a
F 4s
3.18
4.19
9.77
4.72
3.32
−0.19
2.55
0.38
When these values were used to calculate the shifts for the four bis(trifluoromethyl) derivatives, reasonable agreement was found.
TABLE 4
Calculated 19 F Chemical Shifts for 10, 8a-d.
Isomer
Assignment
Calculated
Found
Pseudo
F 2s
−110.73
−112.90
Para
F 2a
−107.85
−108.28
8b
F 1s
−110.49
−111.77
F 1a
−115.01
−115.65
Pseudo
F 1s
−110.10
−112.03
Meta
F 1a
−104.04
−105.86
8a
F 2s
−115.64
−118.29
F 2a
−114.30
−113.56
pseudo
F 2a
−112.90
−112.23
ortho
F 2a
−105.68
−108.07
8c
F 1s
−114.00
−114.75
F 1a
−111.50
−113.16
para
F 2s
−109.96
−112.85
8d
F 2a
−108.42
−109.27
F 1s
−111.26
−114.83
F 1a
−114.44
−113.47
Homo-annular Substitution
When a second identical substituent is introduced into the same ring as the first in an OFP, there are only three possible isomeric products, of which two are meso and one is racemic. The three isomers can in principle be differentiated simply by inspection of the format of the 19 F and 1 H NMR spectra. The para isomer will result in AB patterns in both the 19 F and the 1 H spectra, whereas the ortho isomer will produce 19 F AB's but singlets in the 1 H NMR spectrum. The para meta isomer would also produce no AB patterns in the 19 F spectrum, but would give an AB in the 1 H spectrum. The only isomer to give rise to AB patterns in both fluorine and proton NMR spectra would be the para isomer. This was observed for dibromo OFP, 5d, and bis(trifluoromethyl) OFP, 8b.
Mass Spectrometry
It has been well documented that mass spectroscopic analysis of [2,2] PCP derivatives provides an excellent method for determination of the number of substituents on each ring. This has also been demonstrated to be the case for mono substituted OFP derivatives, and all the new OFP compounds described herein have mass spectra appropriate to the general rules previously established for both the hydrocarbon and fluorocarbon systems.
This technique provides the simplest way to discriminate between homo- and hetero-annular disubstituted isomers. For example, both the para and pseudo para bis(trifluoromethyl)-OFP'S give the same molecular mass of parent ion of 488. The isomer with a trifluoromethyl group in each ring fragments into two xylylene units of mass 244, whereas the homo-annular isomer fragments into unsubstituted and disubstituted xylylene fragments of mass 176 and 312.
Physical Properties
Reich et al., J. AM. CHEM. SOC. (1969) 91, 3534 derived many correlations between physical properties and relative orientation of disubstituted [2,2] PCP isomers. These general relationships proved equally valid for the OFP systems, and indeed were fundamental to our early characterization work. For example, during column chromatography the disubstituted OFP derivatives always eluted in the same order of pseudo meta/ pseudo para, pseudo ortho, pseudo gem. The pseudo meta and pseudo para isomers could never be separated by column chromatography, although they could be separated on a capillary GC (DB5) column. The pseudo paral pseudo meta isomer mixture could be enriched in one isomer or the other by fractional crystallization or sublimation, with the pseudo para isomer being the least soluble and slowest to sublime. In certain cases, analytical samples of pure pseudo para isomer could be obtained by fractional crystallization. The pseudo para isomer was also the isomer with highest melting point.
Characterization Summary
Both the previously established rules and strategies for characterization of [2,2] PCP and monoOFP derivatives are equally applicable to the identification of disubstituted OFP derivatives, and furthermore allow the discrimination between disubstituted OFP isomers. The use of previously derived 1 H SCS values allowed the prediction of 1 H NMR spectra of disubstituted isomers, and also that derived 19F SCS values for trifluoromethyl OFP can be used for the prediction of the 19 F NMR shifts of the bridge fluonnes for bis(trifluoromethylated) OFP isomers. Mass spectroscopy allows the easiest discrimination between homo- and hetero-annular disubstituted isomers.
The following examples are provided for illustrative purposes and are not intended to limit the scope of the claims which follow.
EXAMPLES
Experimental
All NMR spectra were obtained at ambient temperatures in deuterated acetone, and run on a Varian VXR-300 spectrometer with 1 H at 299.949 MHz with TMS as reference, and at 282.202 MHz for 19 F, using CFCl 3 as reference. All reagents, unless otherwise specified, were used as purchased from Aldrich, Milwaukee, Wis. or are Fischer products obtainable from numerous chemical suppliers. Column chromatography was performed using Chromatographic Silica Gel 200-425 mesh as purchased from Fischer. Melting points are uncorrected. Mass spectroscopic analyses were performed on a Finnigan MAT95Q, with an ionizing potential of 70 eV.
Dinitration of OFP
Under a counter current of dry nitrogen, nitronium tetrafluoroborate (22.10 g, 166.17 mmol) was added to octafluoroparacyclophane 1 (10.20 g, 28.98 mmol) dissolved in sulpholane (100 mL), and the reaction was warmed to 80° C. and stirred at this temperature overnight. The reaction mixture was then allowed to cool to room temperature and then added to ice water (400 mL), and the white precipitate was filtered and chromatographed (hexane/dicholormethane 7/3) to give (R f =0.32) pseudo meta- and pseudo para-dinitro 1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 2a,b (6.92 g, 54% combined; 1:1 mixture): MS m/z 442 (M + , 6%), 125 (100); Anal. Calcd for C 16 H 6 F 8 N 2 O 4 : C, 43.44; H, 1.36; N, 6.33. Found: C, 43.70; H, 1.23; N, 6.21; 2a 1 H NMR δ 8.009 (s, 1H); 8.009 (m, 1H); 7.783 (d, 3 J=8.10 Hz, 1H); 19 F NMR δ −108.806 (d, 2 J=244.70 Hz, 1F); −111.989 (d, 2 J=244.70 Hz, 1F); −115.321 (d, 2 J=239.90 Hz, 1F); −117.317 (d, 2 J=239.90 Hz, 1F); 2b 1 H NMR δ 8.009 (s, 1H); 8.009 (m, 1H); 7.783 (d, 3 J=8.10 Hz, 1H); 19 F NMR δ −109.829 (d, 2 J=246.95 Hz, 1F); −113.986 (d, 2 J=246.95 Hz, 1F); −114.352 (d, 2 J=237.36 Hz, 1F); −115.028 (d, 2 J=237.36 Hz, 1F); (R f =0.20) Pseudo ortho-dinitro-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 2c (3.46g, 27%): mp 213-215° C. 1 H NMR δ 8.075 (s, 1H); 7.827 (m, 2H); 19 F NMR δ −111.023 (d, 2 J=244.70 Hz, 1F); −112.293 (d, 2 J=244,70 Hz, 1F); −114.428 (d, 2 J=242.44 Hz, 1F); −115.582 (d, 2 J=242.44 Hz, 1F); MS m/z 442 (M + , 10%), 125 (100); Anal. Calcd for C 16 H 6 F 8 N 2 O 4 : C, 43.44; H, 1.36; N, 6.33. Found C, 43.70; H, 1.29; N, 6.19. The combined yield of the three dinitro isomers is 81%.
When only 4 equivalents of nitronium tetrafluoroborate was used, the product mixture was subjected to chromatography and shown to contain the mononitrated cyclophane (36%), the pseudo meta- 2a (16%), pseudo para- 2b (16%) and pseudo ortho- 2c (16%) dinitro-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes.
Pseudo Ortho-diamino-1,1,2,2,9,9,10,10-Octafluoro [2,2] Paracyclophane, 3c
A suspension of pseudo ortho-dinitro-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 2c (1.30 g, 2.94 mmol) in ethanol/water (1/1 v/v, 50 mL) was stirred for one hour at room temperature. Iron powder (2.00 g, 35.71 mmol) was added, and the reaction mixture was heated to reflux. Concentrated hydrochloric acid (7 mL) was added dropwise to the mixture, and reflux was continued for 4 hours. After this time, the reaction was cooled to room temperature, and was added to ice water (200 mL). The solids thus produced were filtered, and redissolved in chloroform. This chloroform solution was filtered, evaporated and the solid residue was chromatographed (chloroform) to give (R f =0.41) pseudo ortho-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 3c (0.91 g, 82%): mp 211° C. (dec.). 1 H NMR δ 6.999 (d, 3 J=8.40 Hz, 1H); 6.885 (s, 1H); 6.361 (d, 3 J=8.40 Hz, 1H); 19 F NMR δ −106.652 (dd, 2 J=232.56, 3 J=9.60 Hz, 1F); −114.370 (d, 2 J=232.56 Hz, 1F); −106.873 (dd, 2 J=242.44, 3 J=9.60 Hz, 1F); −111.223 (d, 2 J=242.44 Hz, 1F); MS m/z 382 (M + , 19%), 191 (100); Anal. Calcd for C 16 H 10 F 8 N 2 : C, 50.26; H, 2.62; N, 7.33. Found: C, 50.17; H, 2.41; N, 7.21.
An identical reaction with a 1:1 mixture of pseudo meta- and pseudo para-dinitro-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 2a,b gave the corresponding pseudo meta- and pseudo para-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 3a,b in 84% yield. (hexane/chloroform 1/1, R f =0.46): Anal. Calcd for C 16 H 10 F 8 N 2 : C, 50.26; H, 2.62; N, 7.33. Found: C, 49.98; H, 2.55; N, 7.07. MS m/z 382 (M + , 21%), 191 (100); 3a, 1 H NMR δ 7.566 (d, 3 J=8.40 Hz, 1H); 6.442 (d, 3 J=8.40 Hz, 1H); 6.084 (s, 1H); 19 F NMR δ 100.315 (m, 2F); −112.440 (d, 2 J=234.25 Hz, 1F); −116.601 (d, 2 J=234.25 Hz, 1F); 3b, 1 H NMR δ 7.038 (d, 3 J=8.40 Hz, 1H) 6.874 (d, 3 J 8.40 Hz, 1H); 6.003 (s, 1H); 19 F NMR δ 103.339 (d, 2 J=239.33 Hz, 1F); −109.085 (d, 2 J=239.33 Hz, 1F); −108.562 (d, 2 J=234.25 Hz, 1F); −109.685 (d, 2 J=234.25 Hz, 1F).
An ethanol (10 ml) solution containing pseudo ortho dinitro-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 2c (380 mg, 0.86 mmol), cyclohexene (420 mg, 5.16 mmol) and 10% Pd on carbon (0.2 g) was warmed to reflux, and after 15 minutes of observable reflux, the reaction was evaporated under reduced pressure to a solid residue which was subjected to chromatography (chloroform/hexane 7/3, then chloroform) to give three compounds: (R f =0.46) pseudo ortho nitro-amino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 6 (40 mg, 11%): 1 H NMR δ 8.267 (s, 1H); 7.692 (d, 3 J=8.40 Hz, 1H); 7.466 (d, 3 J=8.40 Hz, 1H); 7.107 (d, 3 J=8.40 Hz, 1H); 6.631 (d, 3 J=8.40 Hz, 1H); 6.453 (s, 1H); 5.818 (br s 2H, NH 2 ); 19 F NMR δ −105.172 (d, 2 J=244.70 Hz, 1F); −112.620 (d, 2 J=244.70 Hz, 1F); −106.128 (d, 2 J=239.90 Hz, 1F); −110.660 (d, 2 J=239.90 Hz, 1F); −109.339 (d, 2 J=244.70 Hz, 1F); −112.615 (d, 2 J=244.70 Hz, 1F); −111.964 (d, 2 J=234.82 Hz, 1F); −116.298 (d, 2 J=234.82 Hz, 1F); MS m/z 412 (M + , 25%), 191 (100). HRMS calcd. for C 16 H 8 F 8 N 2 O 2 412.0458, found 412.0481. (R f =0.20, chloroform) pseudo ortho diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 3c (126 mg, 38%), as above. (R f =0.11, chloroform) pseudo ortho hydroxylamino-amino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 7 (51 mg, 15%): 1 H NMR δ 7.609 (s, 1H); 7.118 (d, 3 J=8.40 Hz, 1H); 6.958 (d, 3 J=8.40 Hz, 1H); 6.627 (d, 3 J=8.40 Hz, 1H); 6.373 (d, 3 J=8.40 Hz, 1H); 6.691 (s, 1H); 8.249 (br s, 1H NH); 7.952 (br s, 1H, OH); 5.337 (br s 2H, NH 2 ); 19 F NMR δ 104.796 (d, 2J=242.16 Hz, 1F); −111.062 (d, 2 J=242.16 Hz, 1F); −106.012 (d, 2 J=244.70 Hz, 1F); −111.220 (d, 2 J=244.70 Hz, 1F); −106.120 (d, 2 J=235.10 Hz, 1F); −113.514 (d, 2 J=235.10 Hz, 1F); −106.529 (d, 2 J=232.28 Hz, 1F); −114.462 (d, 2 J=232.28 Hz, 1F); MS m/z 398 (M + , 23%), 207 (5), 191 (100); HRMS calcd. for C 16 H 10 F 8 ON 2 398.0665, found 398.0656.
Typical Diazotization Producedure
A solution of pseudo ortho-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 3c (2.00 g, 5.24 mmol) in acetic acid (4 ml) was cooled to 0° C. in an ice/brine bath, ice (1.5 mL) and concentrated 98% sulfuric acid (1.5 mL) were carefully added with stirring, and ensuring the temperature was still below 0° C., sodium nitrite (2.00 g, 28.99 mmol) was added in one batch. The reaction was stirred at this temperature for 2 hours, and then used for the following transformations:
Pseudo Ortho-dibromo-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane, 5c
An aqueous solution (10 mL) of copper (I) bromide (4.00 g, 27.87 mmol) and 47% hydrobromic acid (10 mL) was warmed to 70° C., and the diazotization solution previously prepared was added in one batch with stirring. The mixture was kept at 70° C. for 1 hour, and then left to cool overnight. The precipitated product was filtered, and chromatographed (hexane/ether 9/1) to give (R f =0.45) pseudo ortho-dibromo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 5c (1.60 g, 60%): mp 125-126° C. 1 H NMR δ 7.845 (s, 1H); 7.520 (d, 3 J=8.10 Hz, 1H); 7.369 (d, 3 J=8.10 Hz, 1H); 19 F NMR δ 109.460 (d, 2J=239.90 Hz, 1F); −113.529 (d, 2 J=239.90 Hz, −110.473 (d, 2 J=239.90 Hz, 1F); −110.620 (d, 2 J=239.90 Hz, 1F); MS m/z 510 (M + , 5%), 508 (2), 512 (2), 254 (100), 256 (94); Anal. Calcd for C 16 H 6 F 8 Br 2 ; C, 37.65; H; 1.18. Found: C, 37.69; H, 1.15.
An identical reaction with a 1:1 mixture of pseudo meta- and pseudo para-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 3a,b gave the corresponding pseudo meta- and pseudo para-dibromo-1,1,2,2,9,9,10,1 0-octafluoro [2,2] paracyclophanes 5a,b in 65% yield: (hexane/chloroform 9/1, R f =0.62); Anal. Calcd for C 16 H 6 F 8 Br 2 : C, 37.65; H, 1.18. Found: C, 37.44; H, 1.13. MS m/z 510 (M + , 4%), 508 (2), 512 (2), 254 (100), 256 (94). 5a 1 H NMR δ 7.428 (s, 1H): 7.799 (d, 3 J=8.10 Hz, 1H); 7.486 (d, 3 J=8.40 Hz, 1H); 19 F NMR δ 103.640 (d, 2 J=239.90 Hz, 1F); −113.529 (d, 2 J=239.90 Hz, 1F); −110.473 (d, 2 J=239.90 Hz, 1F); −110.620 (d, 2 J=239.90 Hz, 1F); 5b 1 H NMR δ 7.165 (s, 1H); 7.895 (d, 3 J=8.40 Hz, 1H); 7.411 (d, 3 J=8.40 Hz, 1H); 19 F NMR δ 108.141 (d, 2 J=239.62 Hz, 1F); −109.137 (d, 2 J=239.62 Hz, 1F); −110.582 (m, 2F).
Pseudo Ortho-diiodo-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane, 4c
An aqueous solution (10 mL) of potassium iodide (5.1 g, 30.78 mmol) was warmed to 70° C., and the diazotization solution previously prepared was added in one batch with stirring. The mixture was kept at 70° C. for 1 hour, and then left to cool overnight. The precipitated product was filtered, and chromatographed (hexane/ether 9/1) to give (R f =0.42) pseudo ortho-diiodo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 4c (2.47 g, 78%): mp 132-133° C. 1 H NMR δ 8.157 (s, 1H); 7.457 (d, 3 J=8.70 Hz, 1H); 7.403 (d, 3 J=8.70 Hz, 1H); 19 F NMR δ 107.330 (d, 2 J=237.36 Hz, 1F); −112.570 (d, 2 J=237.36 Hz, 1F); −109.323 (d, 2 J=239.90 Hz, 1F); −110.319 (d, 2 J=239.90 Hz, 1F); MS m/z 604 (M + , 3%), 302 (100); Anal. Calcd for C 16 H 6 F 8 I 2 : C, 31.79; H, 0.99. Found: C, 31.96; H, 0.92.
An identical reaction with a 1:1 mixture of pseudo meta- and pseudo para-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 3a,b gave the corresponding pseudo meta- and pseudo para-diiodo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 4a,b in 78% yield: (hexane/ether 9/1, R f =0.61); Anal. Calcd for C 16 H 6 F 8 I 2 : C, 31.79; H, 0.99. Found: C, 31.86; H, 0.86. MS m/z 604 (M + , 3%), 302 (100). 4a 1 H NMR δ 7.820 (s, 1H); 7.758 (d, 3 J=8.10 Hz, 1H); 7.450 (d, 3 J=8.10 Hz, 1H); 19 F NMR δ 102.046 (d, 2 J=241.03 Hz, 1F); −105.807 (d, 2 J=241.03 Hz, 1F); −115.704 (d, 2 J=239.90 Hz, 1F); −116.452 (d, 2 J=239.90 Hz, 1F). 4b 1 H NMR δ 7.573 (s, 1H); 7.994 (d, 3 J=8.40 Hz, 1H); 7.482 (d, 3 J=8.40 Hz, 1H); 19 NMR δ 107.109 (d, 2 J=237.36 Hz, 1F); −109.445 (d, 2 J=237.36 Hz, 1F); −108.734 (d, 2 J=237.36 Hz, 1F); −111.322 (d, 2 J=237.36 Hz, 1F).
Pseudo Ortho-diphenyl-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclonhane
Benzene (10 mL) was added to the chilled diazotization solution, and one minute later an aqueous (3 mL) solution of soldium acetate (1.00 g, 12.20 mmol) was added. The bi-phasic mixture was allowed to warm to room temperature overnight with vigorous stirring. Ether was then added, and the bright orange organic phase was separated, dried and evaporated. The crude residue was chromatographed (hexane/dichloromethan 9/1) to give (R f =0.27) 4-phenyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 10 (0.72 g, 32%) and (R f =0.20) pseudo ortho-diphenyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane (0.42 g, 16%): 1 H NMR δ 7.437 (s, 1H); 7.782 (d, 3 J=8.10 Hz, 1H); 7.641-7.523 (m, 5H); 7.452 (d, 3 J=8.10 Hz, 1H); 19 F NMR δ 104.750 (d, 2 J=239.62 Hz, 1F); −113.413 (d, 2 J=239.62 Hz, 1F); −112.688 (d, 2 J=244.70 Hz, 1F); −117.061 (d, 2 J=244.70 Hz, 1F); MS m/z 504 (M + , 8%), 251 (80), 232 (100). HRMS calcd. for C 28 H 16 F 8 504.1124, found 504.1157.
Pesudo Ortho-bis(trifluoromethyl)-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane, 8c
A degassed DMF (40 ml) solution containing pseudo ortho-diiodo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 4c (3.00 g, 4.97 mmol), methly 2-(fluorosulphonyl) difluoroacetate (9.53 g, 49.67 mmol) and palladium dichloride (40 mg, 0.23 mmol) was warmed to 80° C. under a blanket of nitrogen. Copper (I) bromide (5.33 g, 37.25 mmol) was added in one portion, and the mixture was maintained at that temperature overnight. Then the mixture was cooled to ambient temperature before adding ice water. The mixture was stirred for 30 minutes and then the precipitates were removed by filtration and were subjected to column chromatography (hexane/diethyl ether 9/1) affording (R f =0.3 1) pseudo ortho-iodo-trifluoromethyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 9 (0.27 g 10%): 1 H NMR δ 7.309 (s, 1H); 6.726 (s, 1H); 6.892 (d, 3 J=8.40 Hz, 1H); 6.757 (d, 3 J=8.40 Hz, 1H); 6.705 (d, 3 J=8.70 Hz, 1H); 6.652 (d, 3 J=8.70 Hz, 1H); 19 F NMR δ 107.182 (dd, 2 J=242.16, 3 J=7.20 Hz, 1F); −112.966 (dq, 2 J=242.16, 5 J=29.06 Hz, 1F); −107.635 (dd, 2 J=239.90, 3 J=12.10 Hz, 1F); −110.960 (dd, 2 J=239.90, 3 J=7.30 Hz, 1F), −108.138 (dd, 2 J=236.23, 3 J=12.10 Hz, 1F); −110.315 (dd, 2 J=236.23, 3 J=7.30 Hz, 1F); −113.747 (dq, 2 J=234.82, 6 J=14.54 Hz, 1F); −114.623(dd, 2 J=234.82, 3 J=7.20 Hz, 1F); −59.257 (dd, 5 J=29.07, 6 J=14.54 Hz, 3F); MS m/z 546 (M + , 5%), 302 (100), 244 (10). HRMS calcd. for C 17 H 6 F 1 I 545.9339, found 545.9401; (R f =0.17) Pseudo ortho-bis(trifluoromethyl)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 8c (1.65 g, 68%): mp 154-155° C.; 1 H NMR δ 7.493 (s, 1H); 7.733 (m, 2H); 19 F NMR δ 108.067 (dd, 2 J=242.16, 3 J=9.60 Hz, 1F); −112.234 (d,q, 2 J=242.16, 5 J=29.07 Hz, 1F); −113.163 (dd, 2 J=237.36, 3 J=9.60 Hz, 1F); −114.751 (dq, 2 J=237.36, 6 J=14.68 Hz, 1F); −59.160 (dd, 5 J=29.07, 6 J=14.68 Hz, 3F); MS m/z 488 (M + , 5%), 244 (100); Anal. Calcd for C 18 H 6 F 14 : C, 44.26; H, 1.24. Found: C, 44.24; H, 1.02.
An identical reaction with a 1:1 a mixture of pseudo meta- and pseudo para-diiodo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 4a,b gave the corresponding pseudo meta- and pseudo para-bis(trifluoromethyl)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 8a,b in 80% yield: (hexane/ether 9/1, R f =0.67); Anal. Calcd for C 18 H 16 F 14 : C, 44.26; H, 1.24. Found: C, 44.32; H, 1.15. MS m/z 488 (M + , 4%), 244 (100).
There was no evidence of any iodo-trifluoromethyl isomers in this reaction. (It was possible to collect an analytic sample of the more insoluble pseudo para-bis(trifluoromethyl)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 8b by fractional crystallization, which had mp 199-200° C.): 8a 1 H NMR δ 7.824 (s, 1H); 7.710 (d, 3 J=8.40 Hz, 1H); 7.543 (d, 3 J=8.40 Hz, 1H); 19 F NMR δ −105.86 (dq, 2 J=242.16, 6 J=14.68 Hz, 1F); −112.029 (dq, 2 J=242.16, 5 J=29.07 Hz, 1F); −113.562 (d, 2 J=247.24 Hz, 1F); −118.289 (d, 2 J=247.24 Hz, 1F); −58.633 (dd, 5 J=29.07, 6 J=14.68 Hz, 3F); 8b 1 H NMR δ 7.850 (s, 1H); 7.693 (d, 3 J=8.40 Hz, 1H); 7.574 d, 3 J=8.40 Hz, 1H); 19 F NMR δ 107.280 (dd, 2 J=242.16, 3 J=7.06 Hz, 1F); −112.902 (dq, 2 J=242.16, 5 J=31.61 Hz, 1F); −111.769 (dq, 2 J=237.36, 6 J=9.88 Hz, 1F); −115.648 (dd, 2 J=237.36, 3 J=7.06 Hz, 1F); −58.300 (dd, 5 J=31.61, 6 J=9.88 Hz, 3F).
4-Trifluoromethyl-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane, 10
An acetic acid solution (30 mL) containing pseudo ortho-iodo-trifluoromethyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 9 (230 mg, 0.42 mmol) and zinc (110 mg, 1.70 mmol) was refluxed overnight. The mixture was cooled to ambient temperatures and added to ice water (100 mL). The precipitates were collected and subjected to column chromatography (hexane/diethyl ether 8/2) producing (R f =0.56) 4-trifluoromethyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 10 (160 mg, 91%), analytically identical to an authentic sample. 10
Pseudo Ortho-diacetamido-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane
A dichloromethane (5 ml) solution of pseudo ortho-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 3c (200 mg, 0.52 mmol) was warmed to reflux, and acetyl chloride (2 mL) was added dropwise, and the reaction was refluxed overnight. Rotary evaporation afforded a pale brown residue, which after chromatography (hexane/ether 1/9) gave R f =0.60) pseudo ortho-diacetamido-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane (0.24 g, 97%): mp 199-201° C.; 1 H NMR δ 7.818 (s, 1H); 7.392 (d, 3 J=8.10 Hz, 1H); 7.074 (d, 3 J=8.40 Hz, 1H); 8.854 (br s, 1H, NH); 2.243 (s, 3H, CH 3 ); 19 F NMR δ 107.595 (d, 2 J=244.70 Hz, 1F); −111.870 (d, 2 J=244.70 Hz, 1F); −111.439 (d, 2 J=237.36 Hz, 1F); −114.882 (d, 2 J=237.36 Hz, 1F); MS m/z 466 (M + , 27%), 446 (40), 233 (12), 191 (100). Anal. Calcd for C 20 H 14 F 8 N 2 O 2 : C, 51.50; H, 3.00; N, 6.01. Found: C, 51.32; H, 3.05; N, 5.91
An identical reaction with a 1:1 mixture of pseudo meta- and pseudo para-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 3a,b gave the corresponding pseudo meta- and pseudo para-diacetamido-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes in 84% yield: (hexane/ether 4/6, R f =0.44); Anal. Calcd for C 20 H 14 F 8 N 2 O 2 : C, 51.50; H, 3.00; N, 6.01. Found: C, 51.38; H, 2.91; N, 5.91. MS m/z 466 (M + , 5%), 446 (42), 233 (22), 191 (100); pseudo meta isomer: 1 H NMR δ 8.112 (s, 1H); 7.401 (d, 3 J=8.40 Hz, 1H); 7.013 (d, 3 J=8.40 Hz, 1H); 8.817 (br s, 1H, NH); 2.251 (s, 3H, CH 3 ); 19 F NMR δ 103.130 (d, 2 J=247.10 Hz, 1F); −104.959 (d, 2 J=247.10 Hz, 1F); −115.615 (d, 2 J=237.36 Hz, 1F); −115.911 (d, 2 J=237.36 Hz, 1F). pseudo para isomer 1 H NMR δ 7.808 (s, 1H); 7.401 (d, 3 J=8.10 Hz, 1H); 7.082 (d, 3 J=8.10 Hz, 1H); 8.942 (br s, 1H, NH); 2.251 (s, 3H, CH 3 ); 19 F NMR δ −107.616 (d, 2 J=244.70 Hz, 1F); −111.836 (d, 2 J=244.70 Hz, 1F); −113.462 (d, 2 J=237.36 Hz, 1F); −114.314 (d, 2 J=237.36 Hz, 1F).
Pseudo Ortho-bis(trifluoroacetamido)-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane
A solution of pseudo ortho-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 3c (270 mg, 0.71 mmol) in trifluoroacetic anhydride (4 mL) was refluxed overnight. After this time, rotary evaporation yielded a solid residue that after chromatography (chloroform) afforded (R f =0.64) pseudo ortho-bis(trifluoroacetamido)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane (0.39 g, 95%): mp 123-124° C.; 1 H NMR δ 7.550 (s, 1H); 7.470 (d, 3 J=8.40 Hz, 1H); 7.237 (d, 3 J=8.40 Hz, 1H); 9.801 (br s 1H, NH); 19 F NMR δ 109.464 (d, 2 J=247.24, Hz, 1F); −112.265 (d, 2 J=247.24, Hz, 1F); −113.333 (d, 2 J=239.90 Hz, 1F); −114.249 (d, 2 J=239.90, Hz, 1F); −75.832 (s, 3F); MS m/z 574 (M+, 6%), 554 (32), 287 (22), 267(100); Anal. Calcd for C 20 H 8 F 14 N 2 O 2 : C, 41.81; H, 1.39; N, 4.88. Found: C, 41.64; H, 1.29; N, 4.80.
An identical reaction with a 1:1 mixture of pseudo meta-and pseudo para-diamino-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes 3a,b gave the corresponding pseudo meta- and pseudo para-bis(trifluoroacetamido)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes in 97% yield: (hexane/ether 4/6, R f =0.44); Anal. Calcd for C 20 H 8 F 14 N 2 O 2 : C, 41.81; H, 1.39; N, 4.88. Found: C, 41.77; H, 1.34; N, 4.81. MS m/z 574 (M + , 3%), 554 (32), 287 (82), 267 (100); pseudo meta isomer: 1 H NMR δ 7.641 (s, 1H); 7.533 (d, 3 J=8.40 Hz, 1H); 7.252 (d, 3 J=8.40 Hz, 1H); 10.117 (brs, 1H, NH); 19 F NMR δ 107.988 (d, 2 J=247.24 Hz, 1F); −108.255 (d, 2 =247.24 Hz, 1F); −116.278 (d, 2 J=239.90 Hz, 1F); −118.013 (d, 2 J=239.90 Hz, 1F); −75.514 (s, 3F); pseudo para isomer: 1 H NMR δ 7.765 (s, 1H); 7.406 (d, 3 J=8.40 Hz, 1H); 7.374 (d, 3 J=8.40 Hz, 1H); 10.117 (br s, 1H, NH); 19 F NMR δ 111.130 (d, 2 J=246.95 Hz, 1F); −111.292 (d, 2 J=246.95 Hz, 1F); −113.375 (d, 2 J=239.62 Hz, 1F); −115.955 (d, 2 J=239.62 Hz, 1F); −75.574 (s, 3F).
Pseudo Ortho-diphenyl-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane
A degassed THF solution (5 mL) containing pseudo ortho-diiodo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 4c (300 mg, 0.50 mmol) and palladium dichloride (21 mg, 0.12 mmol) was stirred and brought to reflux under a nitrogen atmosphere. A 1M THF solution of phenyl magnesium bromide (3.0 mL, 3.00 mmol) was added via syringe, and the black solution was refluxed overnight. Evaporation of the solvent was followed by the addition ice water, and the precipitated solids were chromatographed (hexane/dichloromethane 9/1) to give (R f =0.44) 4-phenyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 10 (43 mg, 20%), and R f =0.37) pseudo ortho-diphenyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane (53 mg, 21%): 1 H NMR δ 7.437 (s, 1H); 7.782 (d, 3 J=8.10 Hz, 1H); 7.641-7.523 (m, 5H); 7.452 (d, 3 J=8.10 Hz, 1H); 19 F NMR δ −104.750 (d, 2 J=239.62 Hz, 1F); −113.413 (d, 2 J=239.62 Hz, 1F); −112.688 (d, 2 J=244.70 Hz, 1F); −117.061 (d, 2 J=244.70 Hz, 1F); MS m/z 504 (M + , 8%), 251 (80), 232 (100). HRMS calcd. for C 28 H 16 F 8 504.1124, found 504.1157.
Para Dibromi-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane, 5d
A trifluoroacetic acid solution (3 ml) containing 1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 1(1.00 g, 2.84 mmol) and N-bromo-succinamide (2.02 g, 11.35 mmol) was stirred magnetically in a flask protected by a silica drying tube. After 5 minutes, 98% sulfuric acid (1 mL) was added, and left to stir for 16 hrs. After this time analysis by 19 F NMR and TLC showed the presence of starting material, mono-bromo OFP and several dibromide isomers, one of which seemed predominant. The reaction was warmed to 80° C. and left another 12 hrs. The mixture was cooled to ambient temperatures, and added to 100 mL of ice water. The pale yellow precipitate was subjected to column chromatography (hexane/chloroform 50/1), and gave (R f =0.36) para dibromo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 5d (0.65 g, 55%): mp 159-161° C.; 1 H NMR δ 7.416 (s, 1H); 7.970 (d, 3 J=8.40 Hz, 1H); 7.481 (d, 3 J=8.40 Hz, 1H); 19 F NMR δ 110.194 (d, 2 J=237.36 Hz, 1F); −112.642 (d, 2 J=237.36 Hz, 1F); −111.499 (m, 2F); MS m/z 508 (M + , 6%), 510 (13), 512 (6), 334 (5), 254 (53), 256 (49), 176 (100); Anal. Calcd for C 16 H 6 F 8 Br 2 : C, 37.65; H, 1.18. Found: C, 37.81; H, 1.19; (R f =0.20) A mixture of monobromo-, dibromi-(2 isomers) and tribromo-(3 isomers)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes (0.172 g). GLCMS indicted that the dibromo isomers in the second fraction showed one isomer each of hetero- and homo-annular disbtribution, whilst the tribromides all contained 2 bromines on one ring and 1 in the other. This second fraction was not further analyzed.
Para Bis(trifluoromethyl)-1,1,2,2,9,9,10,10-octafluoro [2,2] Paracyclophane, 8d
A degassed DMF (20 mL) solution containing para-dibromo-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 5d (0.53 g, 1.04 mmol) and methyl 2-(fluorosulphonyl) difluoroacetate (0.80 g, 4.16 mmol) was warmed to 100° C. under a blanket of nitrogen. Copper (I) bromide (0.59 g, 4.16 mmol) was added in one portion, and the mixture was maintained at that temperature overnight. Then the mixture was cooled to ambient temperature before adding ice water. The mixture was stirred for 30 minutes and then the precipitates were removed by filtration and were subjected to column chromatography (hexane/diethyl ether 9/1) affording (R f =0.72) para-bis(trifluoromethyl)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 8d (66 mg, 13%): mp 125-126° C.; 1 H NMR δ 7.810 (s, 1H); 7.427 (m, 2H); 19 F NMR δ 109.271 (dd, 2 J=244.67, 3 J=9.88 Hz, 1F); −112.848 (dq, 2 J=244.67, 5 J=29.07 Hz, 1F); −113.468 (dd, 2 J=232.54, 3 J=9.88 Hz, 1F); −114.830 (dq, 2 J=232.54, 6 J=16.93 Hz, 1F); −59.187 (dd, 5 J=29.07, 6 J=16.93 Hz, 3F); MS m/z 488 (M + , 3%), 312 (3), 176 (100); Anal. Calcd for C 18 H 6 F 14 : C, 44.26; H, 1.23. Found: C, 44.47; H, 1.19; (R f =0.40) 4-Trifluoromethyl-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane 10 (74 mg, 17%), whose characterization was identical to an authentic sample. 10
Thermal Isomerization
A tube containing pseudo ortho-bis(trifluoroacetamido)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophane (90 mg, mmol) was evacuated, sealed immersed in a Woods metal heating bath at 381-390° C. for 2 hours. After this time, the tube was cooled, opened and shown by 19 F NMR to contain both pseudo ortho- and pseudo para-bis(trifluoroacetamido)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes in a 5:1 ratio. This material was placed into another identical tube, and again evacuated, sealed and immersed into the Woods metal heating bath and heated at 350-363° C. for 24 hours. The resulting product mixture was shown by 19 F NMR to now contain a 1:7 ratio of pseudo ortho- and pseudo para-bis(trifluoroacetamido)-1,1,2,2,9,9,10,10-octafluoro [2,2] paracyclophanes. Integration versus an internal standard of trifluorotoluene showed the mass balance of the two isomers was 75%.
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Processes for the preparation of parylene dimers, and more particularly to processes for the preparation of derivatives of octafluoro-[2,2]paracylophane, otherwise known as AF4.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a national stage application under 35 U.S.C. §371(c) of prior filed, co-pending PCT application serial number PCT/EP2013/074986, filed on Nov. 28, 2013, which claims priority to Indian Patent Application Serial No. 3689/DEL/2012 filed Nov. 30, 2012 and titled CRYSTALLIZATION and Great Britain Patent Application Serial No. 1300647.3 filed Jan. 15, 2013 and titled CRYSTALLIZATION. All of the above-listed applications are herein incorporated by reference.
TECHNICAL FIELD OF THE INVENTION
[0002] Embodiments of the invention relate to a composition comprising a tricyclic indole compound. More specifically the embodiments of the invention relate to wherein said composition has a more favourable impurity profile as compared with known compositions comprising said compound.
DESCRIPTION OF RELATED ART
[0003] Tricyclic indole compounds are known in the art and have been reported to have application variously as melatonin antagonists (Davies 1998 J Med Chem; 41: 451-467), secretory phospholipase A2 inhibitors (Anderson et at EP 0952149 Al), treatment for Alzheimer's disease (Wantanabe WO 99/25340), treatment of inflammatory diseases such as septic shock (Kinnick et at WO 03/014082 and WO 03/016277) and binders of high affinity to translocator protein (TSPO, formerly known as peripheral benzodiazepine receptor; Wadsworth et at (WO 2010/109007).
[0004] The synthesis of these tricyclic indole compounds comprises a condensation reaction between an analine and a bromo oxocycloalkanecarboxylate, followed by cyclization in the presence of a zinc halide. One problem with this cyclization reaction is that more than one cyclized isomer can result, as illustrated in Scheme 1 below:
[0000]
[0005] The incorrect isomer is formed when the R group reacts with the —OH. This incorrect isomer has similar reactivity to the correct isomer and as a consequence when any further steps are taken to modify the correct isomer, a respective incorrect isomer is generated in the reaction mixture. This is particularly problematic if the resultant compound is intended for in vivo use, as the incorrect isomer will likely compete with the correct isomer for binding to the intended biological target.
[0006] In the method described by Kinnick et at (WO 03/014082), a chloro group was introduced at the R position illustrated in Scheme 1 with the aim of forcing the cyclization reaction to take place in just one way and result in only the correct cyclized isomer. This strategy was applied by Wadsworth et at (WO 2010/109007) in the cyclization reaction illustrated in Scheme 2 below (where Et =ethyl and Bz =benzyl):
[0000]
[0007] Work up and chromatographic purification of the resultant reaction mixture was followed by removal of the chloro group and conversion of the ethyl to diethyl amine to obtain a key intermediate, which in turn was purified using crystallization from diethyl ether. Purity of the key intermediate was still only 71%. When investigating this particular reaction, the present inventors have found that the purified reaction mixture still contains an amount of the incorrect isomer, which is evidently difficult to remove.
[0008] There is therefore a need for a method to obtain these and similar tricyclic indole compounds where the amount of incorrect isomer is reduced or eliminated.
SUMMARY OF THE INVENTION
[0009] Embodiments of the invention relate to a composition comprising a tricyclic indole compound wherein the quantity of an incorrect isomer in said composition is reduced. The composition therefore has a higher purity and better impurity profile than known compositions comprising said tricyclic indole compound and as a consequence has superior properties, particularly when said compound is destined for use in vivo as a therapeutic or diagnostic agent. Also provided by the embodiments of the invention is a method to make the composition of the invention, a pharmaceutical composition comprising the composition of the invention, and use of the composition of the invention in a medical method.
DETAILED DESCRIPTION
[0010] In one aspect, the present invention provides a composition comprising a compound of Formula I:
[0000]
[0000] wherein:
[0011] R 1 is hydrogen, C 1-3 alkyl, C 1-3 alkoxy, or halo;
[0012] R 2 is hydroxyl, halo, cyano, C 1-3 alkyl, C 1-3 alkoxy, C 1-3 fluoroalkyl, or C 1-3 fluoroalkoxy;
[0013] R 3 is —N—R 7 R 8 wherein R 7 and R 8 are hydrogen, C 1-6 alkyl, C 7-10 arylalkyl or, together with R 7 , forms a nitrogen-containing C 4-6 aliphatic ring;
[0014] R 4 is O, S, SO, SO 2 or CH 2 ;
[0015] R 5 is CH 2 , CH 2 —CH 2 , CH(CH 3 )—CH 2 or CH 2 —CH 2 —CH 2 ;
[0016] R 6 is -A 1 -R 9 wherein A 1 is a bond or C 1-10 alkylene, and R 9 is hydrogen, fluoro or a leaving group, or R 9 is the group —O—R 10 wherein R 10 is hydrogen, C 1-3 alkyl, C 3-6 aryl, C 7-10 arylalkyl, or a hydroxyl protecting group,
[0000] wherein said composition comprises no more than 1% of a compound of Formula II:
[0000]
[0000] wherein R 2 to R 6 are as defined for Formula I.
[0017] The term “alkyl” used either alone or as part of another group is defined as any straight —C n H 2n+1 group, branched —C n H 2n+1 group wherein n is >3, or cyclic —C n H 2n−1 group where n is >2. Non-limiting examples of alkyl groups include methyl, ethyl, propyl, isobutyl, cyclopropyl and cyclobutyl.
[0018] The term “alkoxy” refers to an alkyl group as defined above comprising an ether linkage, and the term “ether linkage” refers to the group —C—O—C—. Non-limiting examples of alkoxy groups include, methoxy, ethoxy, and propoxy.
[0019] The term “halo” or “halogen” is taken to mean any one of chloro, fluoro, bromo or iodo.
[0020] The term “hydroxyl” refers to the group —OH.
[0021] The term “cyano” refers to the group —CN.
[0022] The terms “fluoroalkyl” and “fluoroalkoxy”refer respectively to an alkyl group and an alkoxy group as defined above wherein a hydrogen is replaced with a fluoro.
[0023] The term “arylalkyl” refers to an aryl-substituted alkylene group wherein “aryl” refers to any molecular fragment or group which is derived from a monocyclic or polycyclic aromatic hydrocarbon, or a monocyclic or polycyclic heteroaromatic hydrocarbon and “alkylene” refers to a divalent linear —C n H 2n -group.
[0024] A “nitrogen-containing C 4-6 aliphatic ring” is a saturated C 4-6 alkyl ring comprising a nitrogen heteroatom. Examples include pyrolidinyl, piperidinyl and morpholinyl rings.
[0025] The term “leaving group” refers to a molecular fragment that departs with a pair of electrons in heterolytic bond cleavage. Non-limiting examples of suitable leaving groups include halo groups selected from chloro, iodo, or bromo, aryl or alkyl sulfonates such as tosylate, triflate, nosylate or mesylate.
[0026] The term “protecting group” is meant a group which inhibits or suppresses undesirable chemical reactions, but which is designed to be sufficiently reactive that it may be cleaved from the functional group in question to obtain the desired product under mild enough conditions that do not modify the rest of the molecule. Protecting groups are well-known in the art and are discussed in detail in ‘Protective Groups in Organic Synthesis’, by Greene and Wuts (Fourth Edition, John Wiley & Sons, 2007). Non-limiting examples of suitable protecting groups for hydroxyl include acetyl (—COCH 3 ), benzoyl (—COC 6 H 5 ), benzyl (—CH 2 C 6 H 5 ), β-methoxyethoxymethyl ether (MEM), dimethoxytrityl (DMT) and methoxymethyl ether (MOM).
[0027] In a first embodiment R 1 is halo and in a second embodiment R 1 is hydrogen. When R 1 is halo it is more particularly chloro or bromo, and more particularly chloro.
[0028] In an embodiment R 2 is halo, C 1-3 alkoxy or C 1-3 fluoroalkoxy, more particularly hydrogen, halo or C 1-3 alkoxy, more particularly hydrogen, fluoro or methoxy, and more particularly methoxy.
[0029] In an embodiment, R 3 is —N—R 7 R 8 wherein R 7 and R 8 are C 1-6 alkyl or C 7-10 arylalkyl, more particularly wherein R 7 and R 8 are C 1-3 alkyl, more particularly wherein R 7 and R 8 are both ethyl.
[0030] In an embodiment R 4 is CH 2 .
[0031] In an embodiment, R 5 is CH 2 —CH 2 .
[0032] In a first embodiment, R 6 is -A 1 -R 9 wherein A 1 is C 1-10 alkylene, most particularly C 1-3 alkylene and more particularly ethylene, and R 9 is the group —O—R 10 wherein R 10 is C 7-10 arylalkyl or a hydroxyl protecting group, more particularly wherein R 10 is a hydroxyl protecting group.
[0033] In a second embodiment R 6 is -A 1 -R 9 wherein A 1 is C 1-10 alkylene, more particularly C 1-3 alkylene and more particularly ethylene, and R 9 is hydrogen, fluoro or a leaving group. Where R 9 is fluoro it is [ 18 F]fluoro, such that the composition of the invention is an “in vivo imaging composition”. Where R 9 is a leaving group the composition of the invention is a “precursor composition” that can be reacted with [ 18 F]fluoride to obtain the in vivo imaging composition. The leaving group is, in an embodiment, halo, or an aryl or alkyl sulfonate, more particularly an aryl or alkyl sulfonate, and more particularly tosylate, triflate, nosylate or mesylate.
[0034] The term “no more than” should be understood to mean any amount less than the quoted percent quantity. Therefore no more than 1% means any amount between 0-1%. In an embodiment of the composition of the present invention there is 0% of said compound of Formula II in the composition of the invention. However, in reality, it may be that at least a trace amount of the compound of Formula II remains in the composition, i.e. no more than 1% could e.g. refer to 0.1-1%.
[0035] In a first composition of an embodiment of the present invention:
R 1 is halo, more particularly chloro or bromo, and more particularly chloro; R 2 is halo, C 1-3 alkoxy or C 1-3 fluoroalkoxy, more particularly hydrogen, halo or C 1-3 alkoxy, more particularly hydrogen, fluoro or methoxy, and more particularly methoxy; R 3 is —N—R 7 R 8 wherein R 7 and R 8 are C 1-6 alkyl or C 7-10 arylalkyl, more particularly wherein R 7 and R 8 are C 1-3 alkyl, more particularly wherein R 7 and R 8 are both ethyl; R 4 is CH 2 ; R 5 is CH 2 —CH 2 ; and, R 6 is -A 1 -R 9 wherein A 1 is C 1-10 alkylene, more particularly C 1-3 alkylene and more particularly ethylene, and R 9 is the group —O—R 10 wherein R 10 is C 7-10 arylalkyl or a hydroxyl protecting group, more particularly wherein R 10 is a hydroxyl protecting group.
[0042] In a second composition of an embodiment of the present invention:
R 1 is hydrogen;
[0044] R 2 is halo, C 1-3 alkoxy or C 1-3 fluoroalkoxy, more particularly hydrogen, halo or C 1-3 alkoxy, more particularly hydrogen, fluoro or methoxy, and more particularly methoxy;
R 3 is —N-R 7 R 8 wherein R 7 and R 8 are C 1-6 alkyl or C 7-10 arylalkyl, more particularly wherein R 7 and R 8 are C 1-3 alkyl, more particularly wherein R 7 and R 8 are both ethyl; R 4 is CH 2 ; R 5 is CH 2 —CH 2 ; and, R 6 is -A 1 -R 9 wherein A 1 is C 1-10 alkylene, more particularly C 1-3 alkylene and more particularly ethylene, and R 9 is hydrogen, fluoro, or a leaving group, more particularly wherein R 9 is fluoro or a leaving group, wherein said fluoro is [ 18 F]fluoro and wherein said leaving group is, in an embodiment, halo, or an aryl or alkyl sulfonate, more particularly an aryl or alkyl sulfonate, and more particularly tosylate, triflate, nosylate or mesylate. This second composition can therefore either be an in vivo imaging composition or a precursor composition.
[0049] The compound of Formula I and the compound of Formula II of the composition of the embodiments of the invention as defined above may each comprise a chiral centre. All forms of such isomer, including enantiomers and diastereoisomers, are encompassed by the present invention. The compound of Formula I and the compound of Formula II may be present in the composition of the embodiments of the invention as racemic mixture or as an enantiomerically-enriched mixture, or the racemic mixture may be separated using well-known techniques and an individual enantiomer maybe used alone. In an embodiment, the composition of the invention comprises the S-enantiomer of said compound of Formula I and said compound of Formula II.
[0050] In an embodiment, the composition of the present invention comprises no more than 0.5% of said compound of Formula II, more particularly no more than 0.3%, more particularly no more than 0.2%, and more particularly no more than 0.1%.
[0051] In a composition according to an embodiment of the present invention, said compound of Formula I is a compound of Formula Ia:
[0000]
[0000] wherein each of R 1 , R 2 , R 7 , R 8 , R 9 and A 1 are as variously defined hereinabove, and said compound of Formula II is a compound of Formula IIa:
[0000]
[0000] wherein each of R 2 , R 7 , R 8 , R 9 and A 1 are as variously defined hereinabove.
[0052] For a composition according to an embodiment:
R 1 is hydrogen; R 2 is fluoro or methoxy; R 7 and R 8 are C 1-6 alkyl; R 9 is hydrogen, fluoro or a leaving group; and, A 1 is C 1-10 alkylene.
[0058] For a composition according to an embodiment:
R 1 is hydrogen; R 2 is methoxy; R 7 and R 8 are C 1-3 alkyl; R 9 is [ 18 F]fluoro or an aryl or alkyl sulfonate; and, A 1 is C 1-3 alkylene.
[0064] For a composition according to an embodiment:
R 1 is hydrogen; R 2 is methoxy; R 7 and R 8 are methyl or ethyl; R 9 is [ 18 F]fluoro, tosylate, triflate, nosylate or mesylate; and, A 1 is C 1-3 alkylene.
[0070] For a composition according to an embodiment:
R 1 is hydrogen; R 2 is methoxy; R 7 and R 8 are both ethyl; R 9 is [ 18 F]fluoro or mesylate; and, A 1 is ethylene.
[0076] Where an above-defined composition of embodiment of the invention comprises 18 F it is an in vivo imaging composition, and where it comprises a leaving group, it is a precursor composition.
[0077] In another aspect, the present invention comprises a method to obtain the composition as defined hereinabove wherein said method comprises crystallization of a reaction mixture comprising said compound of Formula I as defined hereinabove, and said compound of Formula II as defined hereinabove, wherein said crystallization is carried out in a suitable organic solvent in the presence of a catalytic amount of a weak organic base in order to obtain said composition.
[0078] The term “catalytic amount” means an amount of a substance used in a chemical reaction as a catalyst and is generally much smaller than the stoichiometric amounts of either reactants or products.
[0079] The term “suitable organic solvent” encompasses non-polar solvents and polar aprotic solvents, suitably having a dielectric constant of between 3.5-8. Examples of suitable organic solvents for use in the method of the embodiments of the present invention include diethyl ether, ethyl acetate, tetrahydrofuran (THF) and diisopropylether. Diethyl ether is preferred in some embodiments.
[0080] The term “weak organic base” refers to an organic compound which acts as a base. Organic bases are generally proton acceptors and usually contain nitrogen atoms, which can easily be protonated. Amines and nitrogen-containing heterocyclic compounds are organic bases. Non-limiting examples include pyridine, alkyl amines, morpholine, imidazole, benzimidazole, histidine, phosphazene bases and hydroxides of some organic cations. In the context of embodiments of the present invention alkyl amines are preferred, e.g. N,N-diisopropyl amine, triethyl amine or diethyl amine.
[0081] The present inventors have found that when using the method of embodiments of the invention a very good quality product is obtained having optimum yield. Please refer to Example 1 wherein a method to obtain the composition according to embodiments of the present invention is described. It can be seen that by applying the method of embodiments of the invention to the purification of a key intermediate in the synthesis, the amount of incorrect isomer remaining is significantly less than when the prior art method for purification of this intermediate is used.
[0082] In an embodiment, the reaction mixture for use in the method of the invention is obtained using a method comprising cyclization of a compound of Formula III:
[0000]
[0000] wherein:
R 1 is as suitably and defined hereinabove; R 2 is as suitably and defined hereinabove; R 3 is as suitably and defined hereinabove; R 4 is as suitably and defined hereinabove; R5 is as suitably and defined hereinabove; and, R 5 is as suitably and defined hereinabove; and,
wherein said cyclization is carried out by reaction of said compound of Formula III with a zinc halide.
[0089] In an embodiment, said zinc halide is zinc chloride or zinc bromide, more particularly zinc chloride.
[0090] In an embodiment said zinc chloride is added lot-wise. The term “lot-wise” means introduction of a reagent to a reaction using more than one addition. In the context of embodiments of the present invention said more than one addition comprises a first addition and a second addition wherein said second addition is carried out at least 6 hours after said first addition. Said lot-wise addition, in an embodiment, further comprises a third addition wherein said third addition is carried out said second addition.
[0091] Cyclization of said compound of Formula III is, in an embodiment, carried out wherein R 1 is halogen, more particularly chloro, and wherein R 6 comprises a protecting group. This is to ensure that the cyclization reaction results in as much of the correct isomer as possible.
[0092] The R 1 and R 6 group can be converted subsequently using methods well-known to the person skilled in the art to obtain other R 1 and R 6 groups as defined above.
[0093] Compounds of Formula III can be obtained from commercial starting materials using or adapting methods described in the prior art. Reference is made in this regard to the teachings of Julia & Lenzi (Bulletin de la Société de France 1962: 2262-2263), Davies et at (J Med Chem 1998; 41: 451-467), Kinnick et at (WO 2003/014082 and WO 2003/016277), Anderson et at (EP0952149 B1) and Wadsworth et at (WO 2010/109007). In each of these publications compounds of Formula III are obtained by condensation reaction between an analine and a bromo oxocycloalkanecarboxylate as illustrated in Scheme 3 below:
[0000]
[0000] In the above scheme R′ is an R 3 group as defined herein, R″ is an R 1 and/or an R 2 group as defined herein, R″' is an R 6 group as defined herein and n′ is an integer of 1-3.
[0094] In another aspect, the present invention provides a pharmaceutical composition comprising the composition of the invention together with a biocompatible carrier suitable for mammalian administration.
[0095] In another aspect, the present invention provides a pharmaceutical composition comprising the composition of the invention together with a biocompatible carrier suitable for mammalian administration.
[0096] The “biocompatible carrier” is a fluid, especially a liquid, in which the composition of the invention is suspended or dissolved, such that the pharmaceutical composition is physiologically tolerable, i.e. can be administered to the mammalian body without toxicity or undue discomfort. The biocompatible carrier is suitably an injectable carrier liquid such as sterile, pyrogen-free water for injection; an aqueous solution such as saline (which may advantageously be balanced so that the final product for injection is either isotonic or not hypotonic); an aqueous solution of one or more tonicity-adjusting substances (e.g. salts of plasma cations with biocompatible counterions), sugars (e.g. glucose or sucrose), sugar alcohols (e.g. sorbitol or mannitol), glycols (e.g. glycerol), or other non-ionic polyol materials (e.g. polyethyleneglycols, propylene glycols and the like). The biocompatible carrier may also comprise biocompatible organic solvents such as ethanol. Such organic solvents are useful to solubilise more lipophilic compounds or formulations. In an embodiment, the biocompatible carrier is pyrogen-free water for injection, isotonic saline or an aqueous ethanol solution. The pH of the biocompatible carrier for intravenous injection is suitably in the range 4.0 to 10.5.
[0097] In a yet further aspect, the present invention provides for use of the pharmaceutical composition of the invention in a medical method, wherein said medical method is more particularly either a method for treatment or a method for diagnosis of a pathological condition. In particular, the pharmaceutical composition of embodiments of the present invention is useful in the treatment or diagnosis of a pathological condition comprising inflammation.
[0098] Where the composition of embodiments of the invention is an in vivo imaging composition as referred to above, i.e. wherein R 6 comprises [ 18 F]fluoro, the medical method is more particularly a method of in vivo imaging comprising:
administering said pharmaceutical composition to a subject; detecting signals emitted by the [ 18 F]fluoro comprised in said pharmaceutical composition; and generating an image representative of the location and/or amount of said signals.
[0102] The “subject” of the invention can be any human or animal subject. In an embodiment, the subject of the invention is a mammal. More particularly, said subject is an intact mammalian body in vivo. In an embodiment, the subject is a human.
[0103] “Administering” the in this in vivo imaging method is more particularly carried out parenterally, and more particularly intravenously.
[0104] The “detecting” step of the method of the invention involves detection of signals emitted by the [ 18 F]fluoro by means of a detector sensitive to said signals, i.e. a positron-emission tomography (PET) detector.
[0105] The “generating” step of the method of the invention is carried out by a computer which applies a reconstruction algorithm to the acquired signal data to yield a dataset. This dataset is then manipulated to generate images showing the location and/or amount of signals emitted by said [ 18 F]fluoro.
[0106] The in vivo imaging composition of the invention is readily obtained by reaction with [ 18 F]fluoride of a precursor composition as defined above, i.e. a composition of the invention wherein R 6 comprises a leaving group as defined hereinabove. [ 18 F]-fluoride ion ( 18 FŌ) is normally obtained as an aqueous solution from the nuclear reaction 18 O(p,n) 18 F and is made reactive by the addition of a cationic counterion and the subsequent removal of water. Removal of water is commonly carried out by application of heat and use of a solvent such as acetonitrile to provide a lower boiling azeotrope. A “cationic counterion” is a positively-charged counterion examples of which include large but soft metal ions such as rubidium or caesium, potassium complexed with a cryptand, or tetraalkylammonium salts. In an embodiment, the cationic counterion is a metal complex of a cryptand, more particularly wherein said metal is potassium and wherein said cryptand is Kryptofix 222.
[0107] In another aspect the present invention provides the pharmaceutical composition of the invention for use in any of the above-defined medical methods.
[0108] In a yet further aspect, the present invention provides for use of the composition of the invention in the manufacture of the pharmaceutical composition of the invention for use in any of the above-defined medical methods.
[0109] In a further aspect the present invention provides a kit suitable for making the in vivo imaging composition of the invention, wherein said kit comprises said precursor composition. A specialised kit, or “cassette”, may be used to prepare the in vivo imaging composition of the present invention on an automated radiosynthesis apparatus. By the term “cassette” is meant a piece of apparatus designed to fit removably and interchangeably onto an automated radiosynthesis apparatus, in such a way that mechanical movement of moving parts of the synthesizer controls the operation of the cassette from outside the cassette, i.e. externally. [ 81 F]-radiotracers are now often conveniently prepared on automated radiosynthesis apparatuses. By the term “automated radiosynthesis apparatus” is meant an automated module based on the principle of unit operations as described by Satyamurthy et at (1999 Clin Positr Imag; 2(5): 233-253). The term “unit operations” means that complex processes are reduced to a series of simple operations or reactions, which can be applied to a range of materials. Such automated radiosynthesis apparatuses are commercially available from a range of suppliers (Satyamurthy et al, above), including: GE Healthcare; CTI Inc; Ion Beam Applications S. A. (Chemin du Cyclotron 3, B-1348 Louvain-La-Neuve, Belgium); Raytest (Germany) and Bioscan (USA).
[0110] A commercial automated radiosynthesis apparatus also provides suitable containers for the liquid radioactive waste generated as a result of the radio synthesis. Automated radiosynthesis apparatuses are not typically provided with radiation shielding, since they are designed to be employed in a suitably configured radioactive work cell. The radioactive work cell provides suitable radiation shielding to protect the operator from potential radiation dose, as well as ventilation to remove chemical and/or radioactive vapours. Suitable cassettes comprise a linear array of valves, each linked to a port where reagents or vials can be attached, by either needle puncture of an inverted septum-sealed vial, or by gas-tight, marrying joints. Each valve has a male-female joint which interfaces with a corresponding moving arm of the automated radiosynthesis apparatus. External rotation of the arm thus controls the opening or closing of the valve when the cassette is attached to the automated radiosynthesis apparatus. Additional moving parts of the automated radiosynthesis apparatus are designed to clip onto syringe plunger tips, and thus raise or depress syringe barrels.
[0111] The cassette is versatile, and, in an embodiment, having several positions where reagents can be attached, and several suitable for attachment of syringe vials of reagents or chromatography cartridges (e.g. for SPE). The cassette always comprises a reaction vessel. Such reaction vessels are, in an embodiment, 0.5 to 10 mL, more particularly 0.5 to 5 mL, and more particularly 0.5 to 4 mL in volume and are configured such that 3 or more ports of the cassette are connected thereto, to permit transfer of reagents or solvents from various ports on the cassette. In an embodiment, the cassette has 15 to 40 valves in a linear array, more particularly 20 to 30, with 25 being preferred in an embodiment. The valves of the cassette are in an embodiment each identical, and in an embodiment are 3-way valves. The cassettes are designed to be suitable for radiopharmaceutical manufacture and are therefore manufactured from materials which are of pharmaceutical grade and ideally also are resistant to radiolysis.
[0112] Automated radiosynthesis apparatuses of embodiments of the present invention comprise a disposable or single use cassette which comprises all the reagents, reaction vessels and apparatus necessary to carry out the preparation of a given batch of the in vivo imaging composition of embodiments of the invention.
[0113] The following non-limiting examples serve to illustrate embodiments of the invention in more detail.
BRIEF DESCRIPTION OF THE EXAMPLES
[0114] Example 1 describes a method to obtain a composition comprising a compound of Formula I as defined herein and a compound of Formula II as defined herein, wherein a prior art method is compared with the method of the present invention.
List of Abbreviations Used in the Examples
[0115] OMs: mesylate
Example 1
Synthesis of N,N-diethyl-9-(2-[ 18 F]fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxamide
[0116] The compound N,N-diethyl-9-(2-[ 18 F]fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxamide was synthesised using the following steps:
[0000] Step 1: Synthesis of ethyl 3-bromo-2-oxocyclohexanecarboxylate
[0000]
[0000] Step 2: Synthesis of N-(2-(benzyloxy)ethyl)-2-chloro-5-methoxyaniline
[0000]
[0000] Step 3: Synthesis of ethyl 3-((2-(benzyloxy)ethyl)(2-chloro-5-methoxyphenyl)amino)-2-hydroxycyclohex-1-enecarboxylate
[0000]
[0000] Step 4: Synthesis of ethyl 9-(2-(benzyloxy)ethyl)-8-chloro-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylate
[0000]
[0000] Step 5: Synthesis of 9-(2-(benzyloxy)ethyl)-8-chloro-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxylic Acid
[0000]
[0000] Step 6: Synthesis of 9-(2-(benzyloxy)ethyl)-8-chloro-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carbonyl Chloride
[0000]
[0000] Step 7: Synthesis of 9-(2-(benzyloxy)ethyl)-8-chloro-N,N-diethyl-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxamide
[0000]
[0000] Step 8: Synthesis of 9-(2-(benzyloxy)ethyl)-N,N-diethyl-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxamide
[0000]
[0000] Step 9: Synthesis of N,N-diethyl-9-(2-hydroxyethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxamide
[0000]
[0000] Step 10: Synthesis of 2-(4-(diethylcarbamoyl)-5-methoxy-3,4-dihydro-1H-carbazol-9(2H)-yl)ethyl methanesulfonate
[0000]
[0000] Step 11: Synthesis of N,N-diethyl-9-(2-[ 18 F]fluoroethyl)-5-methoxy-2,3,4,9-tetrahydro-1H-carbazole-4-carboxamide
[0000]
[0117] In the prior art method (Wadsworth et at WO 2010/109007 Example 1), intermediate 10 above was purified by crystallization from diethyl ether (Wadsworth et at WO 2010/109007 Example 1(i)). The method of embodiments of the present invention was carried out as generally described by Wadsworth et at (WO 2010/109007). However, in the method of embodiments of the present invention, intermediate 10 was purified by crystallization from diethyl ether in the presence of diethyl amine.
[0000]
TABLE 1
shows the percent yield of the desired product along with the amount of incorrect
isomer impurity (where measured) in brackets thereafter. With the method of the
invention it can be seen that the amount of the incorrect isomer in intermediate
10, which was purified using the method of the invention was only 0.2%.
Intermediate
6
7
8
10
12
13
Prior Art
95.10
78.20 (6.4)
90.40 (7.6)
92.18 (7.0)
93.15 (4.9)
91.75 (5.1)
Prior Art
91.28
77.97 (6.9)
82 (9.0)
95.40 (3.2)
91.10 (3.3)
92.87 (2.3)
Invention
95.00 (6.5)
84.00 (6.5)
87.27 (5.8)
97.92 (0.2)
—
—
|
A composition comprising a tricyclic indole compound. The composition has a higher purity and better impurity profile than known compositions comprising said tricyclic indole compound and as a consequence has superior properties, particularly when said compound is destined for use in vivo as a therapeutic or diagnostic agent.
| 2
|
BACKGROUND OF THE INVENTION
This invention relates to the field of construction and maintenance of railroad road beds, and particularly to a method for producing usable sleepers or crossties, at economically justifiable cost, from materials usually of value to railroads only as salvage, and also to the compound crossties so produced.
A crosstie is a structural member of the roadbed to the top surface of which rails are secured extending along the roadbed. It is placed upon or embedded in the aggregate ballast to maintain the guage or spacing between the rails and the alignment of the rails, and to distribute the bearing load to the ballast.
Historically, crossties have been produced in this country by sawing or hewing logs of proper length into various sizes ranging in cross section from 5"×5" to 10"×12", and in length from 8 feet, for right-of-way use, to 12 feet, for use at switch turnouts, bridges, etc. Although more expensive, oak is the preferred material for crossties, but other woods are also usable.
After a period of use, crossties become weak, due to deterioration from mechanical wear at the points where the rail is affixed, to longitudinal checking or mechanical failure of the wood, or to attack from biological organisms, so that the crossties can no longer perform their functions, and must be replaced.
Replacement of crossties was first accomplished by pulling the spikes holding the rails to the wood and laterally pulling the entire tie from under the rail, to be replaced with a new tie, after which elevation, alignment, and gauge were reestablished.
This replacement method, accomplished basically by manual labor, resulted in an accumulation of old ties which, although no longer useful for their intended purpose, were still useful as fence posts, for landscape cribbing, etc., and thus had some salvage value.
As labor became more expensive and mechanical technology improved, new track maintenance machines were developed to accomplish removal and replacement of crossties more efficiently and productively. To minimize the amount of readjustment to elevation, alignment, and gauge, it was found to be more efficient to cut the ties into three pieces, while still in place in the roadbed, by means of vertically oscillating saw blades positioned just within the rails, thus producing three pieces of wood. The center section is referred to as the center butt, and the outer sections are referred to as field ends. These sections are too short to have even the salvage value referred to above for entire used crossties, and disposition of these pieces along the right-of-way, as by burning or burial, has disadvantages and in some areas has been prohibited, so it has become necessary to pick up these butts and ends after removal from the roadbed and transfer them, at significant cost, for disposition at suitable landfill areas usually some distance from their site of removal.
Currently, about 26 million crossties are removed annually in the United States, at an average of 32 board feet per crosstie--which represents 832 million board feet of tie material, calling for about 1.4 billion board feet of standing timber. A principal objective of this invention is to reduce so great a demand for standing timbers to be made into crossties.
In the railroad industry, it is the practice to scrap rolling stock when by damage or age it can no longer economically justify repairs. Regularly, steel plate is salvaged from car sides, and brake pipe material and brake rod material is also salvaged, presently for recycling back into steel.
The present invention contemplates constructing usable compound crossties from the scrap steel plate, rod, and pipe just described and the center butts from tie replacement operations. Field ends are generally unusable for the purpose of this invention, but about half the center butts are so usable, two being needed for one complete compound tie.
SUMMARY OF THE INVENTION
The invention comprises a method of manufacturing compound crossties, and the structure of a crosstie so made. Such a crosstie comprises an assembly of two wooden end members, a steel joiner, and a compression member traversing the above members to assemble them into a unitary structure. The joiner, in turn, comprises a pair of end plates extending transverse to an axis, an axial tubular member extending between and beyond the end plates, and reinforcing web means secured to the end plates and the tubular member in unitary relation.
Various advantages and features of novelty which characterize my invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding or the invention, its advantages, and objects attained by its use, reference should be had to the drawing which forms a further part hereof, and to the accompanying descriptive matter, in which there are illustrated and described certain preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing, FIG. 1 is a perspective view of a compound tie according to my invention, shown in its intended relation to a pair of rails;
FIG. 2 is a view in perspective of a joiner according to my invention, to a larger scale;
FIG. 3 is a longitudinal section of the structure of FIG. 1 to a larger scale, the section being taken along the line 3--3 of FIG. 1;
FIG. 4 is a transverse sectional view of the joiner, taken along the line 4--4 of FIG. 1, to a larger scale;
FIG. 5 is a fragmentary view in perspective of one end of a modified joiner; and
FIG. 6 is a fragmentary view similar to a portion of FIG. 3 but to a larger scale, and showing the embodiment of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The roadbed of a railroad comprises a pair of rails maintained in elevation, alignment, and gauge by being secured to supporting crossties by spikes overlying the base of the rail and passing through tie plates into the wood of the crosstie. Ordinarily the crossties rest on and are embedded in ballast of crushed rock or cinders. FIG. 1 shows a fragment of such a roadbed schematically: rails 10 and 11 are secured to a compound crosstie 12 by spikes 13 passing through tie plates 14 into the end members 15 and 16 of the crosstie, which are of wood and are spaced by a joiner 17, being maintained in assembly therewith by a compressional member or tie rod 20 threaded at its ends to receive nuts 21 and washers 22 which bear against suitable outer plates 23 secured to the outer surfaces of members 15 and 16 by nails 24 passing through holes 25 provided in the plates.
As shown in detail in FIGS. 2 and 4, joiner 17 is a steel weldment and comprises a pair of inner end plates 30 and 31, a central tubular member 32, and reinforcing means in the form of a pair of interior braces 33 and 34. Plates 30 and 31 extend transverse to the axis of member 32, which extends between and beyond the plates and is welded thereto. Braces 33 and 34 are of steel plate formed into right-angle configurations: they are welded at their ends to inner plates 30 and 31, and along their apices to member 32. Plates 30 and 31 are provided with holes 35, as in plates 23, to pass nails 36 driven into the inner ends of members 15 and 16: these nails prevent rotation of members 15, 16, and 17 relative to one another about the axis of member 32.
Plates 23, 30, and 31 are sheared and punched from salvage material, braces 33 and 34 are sheared and bent from the same material, and member 32 is cut from salvage pipe, so that the only costs for materials for joiner 17 are the salvage values of the materials and the labor and machine costs for cutting, forming and welding it.
Members 15 and 16 are bored centrally lengthwise, as shown at 40, 41, to receive the ends of member 32 which extend beyond plates 30 and 31. As also clearly shown, tie rod 20 need not be a close fit in the bores or in member 20 and plates 23. The only requirements for this rod are that it be long enough to extend from end to end of the assembly, and that it be strong enough to resist deformation of the complete assembly when in use.
The joiner 57 of FIGS. 5 and 6 differs from that just described only in substituting for holes 35 a plurality of triangular spuds 58 struck out from the metal of plate 61 and arranged to extend therebeyond when the joiner is assembled, so that the spuds 58 penetrate into the wood of members 15 and 16 and prevent the relative rotation described in connection with nails 36.
By way of illustration only, dimensions and procedural steps for making compound crossties according to the invention are given below. From sections of salvaged car side plate material are die-stamped and punched the 5"×6" plates 23, 30, 31. Plates 51/2"×215/8" are sheared and bent at right angles along their longer axes to form the internal braces 33 and 34. Sections of brake pipe 26" long and brake rod 9 feet long are cut, and the rod ends are threaded for 21/2" at each end. Braces 33, 34 are centered on and welded to tubular member 32, and inner end plates 30, 31 are welded to the ends of the internal braces and to the tubular member. This work is done at a car salvage facility.
The center butts, gathered from wherever tie replacement is being done, are transported to the facility just named and are graded for soundness. Sound butts are processed as will now be itemized: no preservative treatment is applied at this time:
1. passage through high pressure debarking jets of water to remove dirt, stones, and foreign matter;
2. passage through opposing sets of wire brush rolls to mechanically pick out foreign matter not removed in step 1;
3. passage through a double-end trimmer to remove rough edges resulting from field sawing and reduce the length to 40";
4. passage through a two-arbor abrasive planer to resurface the "wide" sides, top and bottom;
5. drilling coaxially in two successive operations from opposite ends;
6. assembly
(a) insert joiner between two reprocessed center butts;
(b) insert tie rod;
(c) bolt on outer plates with impact wrenches; and
(d) insert nails with pneumatic nailing guns; and
7. adze and drill for tie plate acceptance in a conventional tie adzing and drilling machine.
It has been determined that the procedures described above result in usable compound crossties at economically justifiable prices: this is advantageous because the supply of suitable standing timber of adequate size is dwindling, and the cost of crossties is multiplying, as is the cost for seasoning and treating wood ties and maintaining an adequate inventory. By practicing my invention, for each million ties replaced, 250,000 compound ties can be constructed, reducing by 8 million board feet the demand for tie material and by about 13.4 million board feet the demand for standing timber.
From the foregoing, it will be evident that I have invented a new and useful compound crosstie for railroad use, and a new process for making such crossties out of material having at most scrap or salvage value.
Numerous characteristics and advantages of my invention have been set forth in the foregoing description, together with details of the structure and function of the invention, and the novel features thereof are pointed out in the appended claims. The disclosure, however, is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts, within the principle of the invention, to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
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A compound cross tie for railroad use, the method of making it, and a joiner used therein. The cross tie comprises a pair of wooden end members connected axially by the joiner, and a compressional member traversing the entire assembly: means are provided to prevent relative rotation among the various components.
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BACKGROUND OF THE INVENTION
The present invention relates to hard-surface cleaning compositions especially suited for the cleaning of polished surfaces and methods of using such compositions.
The cleaning of hard surfaces with a variety of compositions is old in the art. The compositions have taken the form of granular solids or liquids while containing such things as scouring and bleaching agents in addition to cleaning surfactant compounds. The interest in providing such compositions, particularly those in liquid form, with antibacterial effectiveness is evidenced by many patents and literature references. Achieving such effectiveness has been the result of using phenolic compounds or quaternary ammonium or other nitrogenous compounds. The presence of such nitrogenous compounds also means that amine impurities are likely to be present. These impurities present a variety of problems, some of which are particularly acute when the compositions are used on polished surfaces.
Many modern floor polishes use carboxyl-containing acrylic copolymers as the basis for detergent and acid resistant, ammonia-removable floor polishes. These copolymers are formed by using a high proportion of acrylic and methacrylic acids, and they are usually cross-linked with a polyvalent metal ion, commonly zirconium or zinc, to form a durable film. This film can be removed with a cleaning solution containing ammonia, the ammonia forming a soluble metal ammoniate complex.
Since the above-mentioned floor polishes are removable by the use of ammonia, the amine impurities which are present in compositions of the instant invention can, through the same chemical interaction, cause the polish to soften and be susceptible to removal. This is undesirable since the polish in such a condition may have a sticky feel and the polished surface will have an unclean, streaky appearance.
It has been found in the present invention that the aforementioned problems can be diminished by the addition of a small amount of a water-soluble metal ion salt to the cleaning composition. It is believed that the metal ion of the salt complexes the amines present thereby preventing them from weakening the cross-linked polish.
It is, therefore, an object of the present invention to provide hard-surface cleaning compositions wherein the tendency of the compositions to soften polishes is substantially reduced.
It is a further object of the present invention to provide a superior method of cleaning polished surfaces.
These and other objects of the present invention will become obvious from the discussion of the invention which appears hereinafter.
PRIOR ART
As indicated hereinabove, extensive work has been done in the area of cleaning compositions containing quaternary ammonium compounds and other nitrogenous compounds such as amines and zwitterionic surfactants. Included among references which disclose such compositions are Voss, U.S. Pat. No. 3,507,796, issued Apr. 21, 1970; Freese, U.S. Pat. No. 3,093,591, issued June 11, 1963; Hibbs, U.S. Pat. No. 2,541,248, issued Feb. 13, 1951; Herrick et al., U.S. Pat. No. 3,247,119, issued Apr. 19, 1966; Lancz, U.S. Pat. No. 3,812,046, issued May 21, 1974; Gaines, U.S. Pat. No. 3,560,390, issued Feb. 2, 1971; Dadekian, U.S. Pat. No. 3,836,699, issued Sept. 17, 1974; and Japanese Patent Application -084471 T28, published July 7, 1972.
SUMMARY OF THE INVENTION
The present invention, in its composition aspect, relates to aqueous hard-surface cleaning compositions comprising an amine derived nitrogenous surfactant, amine impurities which are present as the result of being introduced with the surfactant, a water-soluble salt of a metal ion which is capable of complexing amines in an amount such that the molar ratio of metal salt to amine is from about 1:1 to 1:4 and water. The pH of the present compositions is from about 6 to 8.
In its method aspect the present invention is related to the use of the above-described compositions to clean hard surfaces without adversely softening the polish which may be present on such surfaces.
DETAILED DESCRIPTION OF THE INVENTION
The present compositions comprise several components each of which is described in turn below.
Nitrogenous Surfactant
The amine derived nitrogenous surfactant for use in the present invention can be selected from a wide variety of materials. Included among such materials, and those which are preferred for use herein, are cationic, ampholytic and zwitterionic surfactants. In addition, certain nonionics are also preferred. Cationic surfactants are preferred components when it is desired to have the compositions possess bactericidal activity.
The cationic surfactants include such materials as
A. quaternary ammonium compounds having the formula ##STR1## wherein R 16 is an alkyl radical containing from about 6 to about 22 carbon atoms, from 0 to about 2 halogen atoms, and from 0 to about 1 additional quaternary ammonium group having the formula ##STR2## said quaternary ammonium group being attached so that there is at least one alkyl moiety of at least about 6 carbon atoms containing no amine group or quaternary ammonium group as a substituent, and each R 1 group is selected from the group consisting of alkyl groups containing from 1 to about 22 carbon atoms, mono halogen substituted alkyl groups containing from 1 to about 3 carbon atoms, benzyl groups and hydroxyl alkyl groups containing from 1 to 3 carbon atoms, said halogen atoms and said hydroxyl groups being substituted on any of the carbon atoms in the alkyl groups and wherein X is selected from the group consisting of iodide, bromide, methylsulfate, ethylsulfate and chloride anions;
B. n-alkyl pyridinium halides wherein the alkyl group contains from about 6 to about 18 carbon atoms;
C. 2-alkyl quaternary imidazolinium salts wherein the alkyl group contains from about 8 to about 18 carbon atoms;
D. polyquaternary ammonium compounds having the formula: ##STR3## wherein R 5 is a hydrocarbon group containing from 1 to about 24 carbon atoms, wherein said R 6 group is a hydrocarbon group containing from 1 to about 4 carbon atoms, wherein X 1 is selected from the group consisting of chlorine, iodine, and bromine atoms, wherein L, m and n are integers such that L is an integer from 0 to about 50, the sum of m and n is from 2 to about 50, and the sum of m, n the number of carbon atoms in R 5 is greater than 12;
E. organosilicon quaternary ammonium halides ##STR4## F. bisbiguanides (e.g., 1,1'-hexamethylene bis[5-(p-chlorophenyl)biguanide]; and
G. mixtures thereof.
While any of the above types of cationic surfactants are suitable for use herein certain ones are preferred. Included in the preferred group are dialkyldimethylammonium chloride, alkyldimethylbenzylammonium chloride, alkyl pyridinium chloride, alkyl trimethylammonium chloride, and mixtures thereof. The alkyl group in such compounds preferably being from about 6 to 18 carbon atoms. It should be appreciated that the anionic portion of such salts can be other halogens such as bromide or groups such as methylsulfate.
The ampholytic synthetic detergents can be broadly described as derivatives of aliphatic or aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic radical may be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and at least one contains an anionic water-solubilizing group, e.g., carboxy, sulfonate, sulfato. Examples of compounds falling within this definition are
sodium 3-(dodecylamino)propionate,
sodium 3-(dodecylamino)propane-1-sulfonate,
sodium 2-(dodecylamino)ethyl sulfate,
sodium 2-(dimethylamino)octadecanoate,
disodium 3-(N-carboxymethyldodecylamino)propane-1-sulfonate,
disodium octadecyl-iminodiacetate,
sodium 1-carboxymethyl-2-undecylimidazole, and
sodium N,N-bis(2-hydroxyethyl)-2-sulfato-3-dodecoxypropylamine.
The zwitterionic synthetic detergents useful herein can be broadly described as derivatives of aliphatic quaternary ammonium and phosphonium or tertiary sulfonium compounds, in which the cationic atom may be part of a heterocyclic ring, and in which the aliphatic radical may be straight chain or branched, and wherein one of the aliphatic substituents contains from about 3 to 18 carbon atoms, and at least one aliphatic substituent contains an anionic water-solubilizing group, e.g., carboxy, sulfonate, sulfato, phosphato, or phosphono. Examples of compounds falling within this definition are
3-(N,N-dimethyl-N-C 8-21 alkylammonio)-2-hydroxypropane-1-sulfonate,
3-(N,N-dimethyl-N-dodecylammonio)acetate,
3-(N,N-dimethyl-N-dodecylammonio)-propionate,
2-(N,N-dimethyl-N-octadecylammonio)ethyl sulfate,
2-(trimethylammonio)ethyl dodecylphosphonate,
ethyl 3-(N,N-dimethyl-N-dodecylammonio)propylphosphonate,
sodium 2-(N,N-dimethyl-N-dodecylammonio)ethyl phosphonate,
1-(2-hydroxyethyl)-2-undecylimidazolium-1-acetate,
2-(trimethylammonio)octadecanoate, and
3-N,N-bis-(2-hydroxyethyl-N-octadecylammonio)-2-hydroxypropane-1-sulfonate.
Some of these detergents are described in the following: U.S. Pat. Nos. 2,129,264; 2,178,353; 2,774,786; 2,813,898; and 2,828,332. The ammoniopropane sulfonates containing about 8 to about 21 carbon atoms are one class of detergent compounds preferred herein.
Amine derived nitrogenous nonionic surfactants are also included herein. Such compounds may be derived from the condensation of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine. For example, compounds containing from about 40 to about 80 percent polyoxyethylene by weight and having a molecular weight of from about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydrophobic base constituted of the reaction product of ethylene diamine and excess propylene oxide, said base having a molecular weight of the order of 2,500 to 3,000, are satisfactory.
Additional amine derived nonionics are those having the formula R 1 R 2 R 3 N→O (amine oxide detergent) wherein R 1 is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R 1 which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each R 2 and R 3 are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms.
Specific examples of amine oxide detergents include: dimethyldodecylamine oxide, dimethyltetradecylamine oxide, ethylmethyltetradecylamine oxide, cetyldimethylamine oxide, dimethylstearylamine oxide, cetylethylpropylamine oxide, diethyldodecylamine oxide, diethyltetradecylamine oxide, di-propyldodecylamine oxide, bis-(2-hydroxyethyl)dodecylamine oxide, bis-(2-hydroxyethyl)-3-dodecoxy-1-hydroxypropylamine oxide, (2-hydroxypropyl)methyltetradecylamine oxide, dimethyloleyamine oxide, dimethyl-(2-hydroxydodecyl)amine oxide, and the corresponding decyl, hexadecyl and octadecyl homologs of the above compounds.
Other surfactants include bis-(N-2-hydroxyethyl) lauramide and lauramide condensed with 15 moles of ethylene oxide per mole of lauramide.
The nitrogenous surfactant in the compositions of the present invention can be a mixture of such surfactants and is generally present in a total amount of about 0.5% to 20% by weight of the composition. If it is intended for the compositions to possess bactericidal properties, it is preferred that the composition contain from about 0.5% to about 10% of a cationic surfactant, more preferably from about 1.5% to about 3%. The ampholytic and zwitterionic surfactants preferably comprise up to about 10% of such compositions, more preferably up to about 3%.
Amine Impurities
The amine impurities present in the instant compositions are generally the result of incomplete reactions in the formation of the nitrogenous surfactant. These amines can be primary, secondary or tertiary. All such amines adversely affect waxed surfaces and are desirably complexed. A common type of amine impurity found with the aforementioned surfactants is an alkyl dimethyl amine. The level of amine impurities can be determined by a common laboratory technique such as a straightforward acid-base titration wherein a given volume of aqueous surfactant solution is titrated with a standard acid (HCl, HNO 3 ) solution to a bromophenol blue endpoint. The free amine R 3 N content in the surfactant solution can be calculated from the volume of standard acid required to reach the endpoint. The quaternized R 3 NH + amine content can be determined by titrating the aqueous surfactant solution with a standard aqueous base (NaOH, KOH) solution to a phenolphthalein endpoint prior to the aforementioned acid titration.
Metal Ion Salt
The materials used to complex the amine impurities present herein are water-soluble salts of metal ions capable of complexing amines. Included among such metals are the transition metals and zinc. The particular metal ion chosen for use herein is not critical, although certain ones are preferred because of availability and other reasons. The same is true of the anionic portion of the salt. The preferred metal ions include zinc, (II), cobalt (II), nickel (II), zirconium (II), titanium (II), copper (II), chromium (II), iron (II), and manganese (II). The preferred anionic portions include the halogens, chlorine, bromine and fluorine, acetate, sulfate and nitrate, among others. By water-soluble herein is meant a solubility of at least 1% by weight at 25° C.
The most preferred salts for use herein are the salts of zinc, cobalt, zirconium and nickel wherein the anionic portion is a halogen, preferably chloride. The most preferred salt is zinc chloride.
As indicated hereinbefore, the metal salt is present in a molar ratio of from about 1:1 to about 1:4, metal salt to amine.
Optional Components
The present compositions can contain as optional components a variety of materials depending on the intended use of the composition. A preferred optional ingredient is a nonionic surfactant which is not nitrogenous and, when the nitrogenous surfactant portion does not contain a cationic surfactant, anionic surfactants. Nonionic synthetic detergents may be broadly defined as compounds produced by the condensation of alkylene oxide groups (hydrophilic in nature) with an organic hydrophobic compound, which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.
For example, a well known class of nonionic synthetic detergents is made available on the market under the trade name of "Pluronic." These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water-insolubility, has a molecular weight of from about 1500 to 1800. The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about 50 percent of the total weight of the condensation product.
Other suitable nonionic synthetic detergents include:
1. The polyethylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing from about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 3 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds may be derived from polymerized propylene, diisobutylene, octene, or nonene, for example.
2. The condensation product of aliphatic alcohols having from 8 to 22 carbon atoms, in either straight chain or branched chain configuration with ethylene oxide, e.g., a coconut alcohol-ethylene oxide condensate having from 3 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having from 10 to 14 carbon atoms.
3. Nonionic detergents include nonyl phenyl condensed with about 10 to about 30 moles of ethylene oxide per mole of phenol; the condensation products of coconut alcohol with an average of either about 5.5 or about 15 moles of ethylene oxide per mole of alcohol; and, the condensation product of about 15 moles of ethylene oxide with one mole of tridecanol.
Other examples include dodecylphenol condensed with 12 moles of ethylene oxide per mole of phenol; dinonylphenol condensed with 15 moles of ethylene oxide per mole of phenol; dodecyl mercaptan condensed with 10 moles of ethylene oxide per mole of mercaptan; nonyl phenol condensed with 20 moles of ethylene oxide per mole of nonyl phenol; myristyl alcohol condensed with 10 moles of ethylene oxide per mole of myristyl alcohol; and di-isooctylphenol condensed with 15 moles of ethylene oxide.
4. A detergent having the formula R 1 R 2 R 3 P→O (phosphine oxide detergent) wherein R 1 is an alkyl group containing from about 10 to about 28 carbon atoms, from 0 to about 2 hydroxy groups and from 0 to about 5 ether linkages, there being at least one moiety of R 1 which is an alkyl group containing from about 10 to about 18 carbon atoms and 0 ether linkages, and each of R 2 and R 3 are selected from the group consisting of alkyl radicals and hydroxyalkyl radicals containing from 1 to about 3 carbon atoms.
Specific examples of the phosphine oxide detergents include: dimethyldodecylphosphine oxide, dimethyltetradecylphosphine oxide, ethylmethyltetradecylphosphine oxide, cetyldimethylphosphine oxide, dimethylstearylphosphine oxide, cetylethylpropylphosphine oxide, diethyldodecylphosphine oxide, diethyltetradecylphosphine oxide, dipropyldodecylphosphine oxide, bis-(hydroxymethyl)dodecylphosphine oxide, bis-(2-hydroxyethyl)dodecylphosphine oxide, (2-hydroxypropyl)methyltetradecylphosphine oxide, dimethyloleylphosphine oxide, and dimethyl-(2-hydroxydodecyl)phosphine oxide and the corresponding decyl, hexadecyl, and octadecyl homologs of the above compounds.
5. A detergent having the formula ##STR5## (sulfoxide detergent) wherein R 1 is an alkyl radical containing from about 10 to about 28 carbon atoms, from 0 to about 5 ether linkages and from 0 to about 2 hydroxyl substituents at least 1 moiety of R 1 being an alkyl radical containing 0 ether linkages and containing from about 10 to about 18 carbon atoms, and wherein R 2 is an alkyl radical containing from 1 to 3 carbon atoms and from 1 to 2 hydroxyl groups: e.g., octadecyl methyl sulfoxide, dodecyl methyl sulfoxide, tetradecyl methyl sulfoxide, 3-hydroxytridecyl methyl sulfoxide, 3-methoxytridecyl methyl sulfoxide, 3-hydroxy-4-dodecoxybutyl methyl sulfoxide, octadecyl 2-hydroxyethyl sulfoxide, and dodecylethyl sulfoxide.
The anionic surfactants which may be present in certain of the present compositions include water-soluble salts, particularly the alkali metal salts, of organic sulfuric reaction products having in their molecular structure an alkyl substituent containing from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester moiety. (Included in the term alkyl is the alkyl portion of higher acyl substituent.) Examples of this group of synthetic detergents which may form a part of the compositions of the present invention are the sodium or potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C 8 -C 18 carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium or potassium alkyl benzene sulfonates, in which the alkyl group contains from about 9 to about 15 carbon atoms in straight chain or branched chain configuration, e.g., those of the type described in U.S. Pat. Nos. 2,220,099 and 2,477,383 (especially valuable are linear straight chain alkyl benzene sulfonates in which the average of the alkyl groups is about 13 carbon atoms and commonly abbreviated as C.sub. 13 LAS); sodium alkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium salts of sulfuric acid esters of the reaction product of 1 mole of a higher fatty alcohol (e.g., tallow or coconut oil alcohols) and about 1 to 6 moles of ethylene oxide; sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate with about 1 to about 10 units of ethylene oxide per molecule and in which the alkyl radicals contain about 8 to about 12 carbon atoms.
The above-mentioned optional surfactants, if present, are present at a total level of up to about 15%. If the optional surfactant is nonionic alone, it is preferably present at a level of up to about 10%, more preferably up to about 2%.
Another optional ingredient suitable for use herein are pH control agents which are compatible with the metal salts. Included among such agents are borate, sulfate, citrate, acetate and succinate buffers. When such agents are used, they are present at a level of about 1% to 20%.
For aesthetic purposes the present compositions can contain perfumes and dyes in an amount up to about 0.5%. Additional agents such as preservatives (e.g., glutaraldehyde), thickeners, hydrotropes, opacifiers, solvents (e.g., ethyl alcohol, isopropyl alcohol, glycerin and glycols) and stabilizers may also be present. Additionally, phenolic antibacterial agents may be present as the only antibacterial or in combination with others.
Composition Manufacture
The compositions of the present invention are prepared by conventional mixing techniques. The order of addition of the components is not critical and the components are simply mixed together until solution is achieved.
Composition Usage
The present compositions can be used either at full strength or in a diluted form on the surface to be cleaned. The composition, if diluted, is generally mixed with water in an amount of one part composition to about 64 parts of water. The treated surface is rubbed in an oscillating manner with a sponge or other similar material to distribute the composition. If desired the surface can be rinsed with clean water. When used at full strength, the composition is used in an amount of from about 0.05 gms. to 3.00 gms. per square foot of surface.
A preferred composition for use herein contains from about 1.5% to 3% of a bactericidal quaternary ammonium compound, up to 3% of a zwitterionic surfactant, up to 2% of a nonionic surfactant, about 0.0025% to 0.05% of zinc chloride, an amount of a pH control agent to provide a pH of about 6 to 8, and water.
Maintaining the pH of the present type of products in the acidic range helps to prevent polish damage. The reason for this is that the free amines tend to be quaternized at such pH's and the susceptible polishes are more stable in an acidic environment that in an alkaline environment. However, in order to maintain the effectiveness of bactericidal quaternary ammonium compounds it is desirable to maintain the pH above about 6.
All percentages used herein are by weight unless otherwise specified.
The invention will be further illustrated by the following examples.
EXAMPLE I
A composition of the present invention is formulated as shown below:
______________________________________Cetyl trimethylammonium bromide 3.00%3-(N,N-dimethyl-N-C.sub.12.8 alkylammonio)- 2-hydroxy propane-1-sulfonate (HAPS) 1.60Secondary alcohol ethoxylate nonionic surfactant (C.sub.11-15 ; EO-9) 1.00Perfume 0.50Zinc chloride 0.005Water Balance 100.00% pH = 7.0______________________________________
When the above composition is used on a polished surface at full strength in an amount of 0.45 grams per square foot, the wax does not soften or smear as it does when the identical composition with the zinc chloride removed is used.
EXAMPLE II
A composition is formulated similar to that of Example I except that the HAPS level is reduced to 0.4% and the nonionic surfactant is eliminated. The performance of this composition on polished surfaces is similar to that of the composition of Example I.
EXAMPLE III
A composition is formulated similar to that of Example I except that the zinc chloride level is reduced to 0.01%. The performance of this composition is similar to that of the composition of Example I.
EXAMPLE IV
A composition is formulated similar to that of Example I except that zinc chloride salt is replaced by the acetate, bromide, sulfate or nitrate salt of zinc, cobalt or nickel. Performance of compositions containing these salts is similar to that of the composition of Example I.
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Hard-surface cleaning compositions especially suited for cleaning polished surfaces contain amine compounds as impurities and a sufficient amount of a metal ion to complex the amines thereby preventing them from attacking the polish composition. Methods of using the compositions are also provided.
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This application is a division of application Ser. No. 09/640,745 filed Aug. 18, 2000 U.S. Pat. No. 6,334,899, which is a division of application Ser. No. 09/504,961 filed Feb. 16, 2000, now U.S. Pat. No. 6,153,011, which is a division of application Ser. No. 09/234,411 filed Jan. 21, 1999, now U.S. Pat. No. 6,071,339, which is a division of application Ser. No. 08/490,893 filed Jun. 16, 1995, now U.S. Pat. No. 5,993,540.
BACKGROUND OF THE INVENTION
This invention relates to the purifying of crystal material, the doping of the material and the growth of crystals.
Bridgeman, Bridgeman-Stockbarger, Czochralski and variations have been used for crystal growth. Depending on the crystal growth method, the crystal type and the crystal size, one has to overcome sets of problems. This invention relates to the purification of the crystal material and the crystal growth process itself.
Crystal size and the quality of the crystal starting material play important roles in the production of scintillation crystals. The starting material labeled “scintillation grade” is of five 9's purity 0.9999%. Often the starting material has poor stoichiometry ratio. Growing crystals in a closed type system that have large diameters and up to over 2000 pounds in weight result in crystals that have poor crystal quality. Crystal purity, dopant distribution, defect density and distribution and built-in stress imposed on the crystal during the crystal growth process and the crucible removal may be at unacceptable levels. With the exception of small crystal portions grown at the beginning of the crystal growth, crystals may have lower purity than the starting material. Dopant concentration varies dramatically. That in turn creates uneven light output and decreases the energy resolution of scintillation crystals. When handling large size crystals during the hot transfer, the crystals release large portions of iodine and thallium iodine vapors. Exposure to ambient temperature creates various defects and defect densities in the hot crystals.
The current practices where large barrel-shaped crystals are grown for all applications, regardless of the fact that most applications use rectangular shapes, makes the yields rather low. Scaling up crystal plate sizes from 0.5-1 inch thick slabs cut perpendicular to the crystal length of a barrel-shaped crystal requires large financial investments. At the same time increasing slab geometry increases the crystal production cost by decreasing the growth rate and lowers the crystal quality and yield.
Existing purification methods include supplying a gaseous medium to a surface of a melt carried in a crucible. Those methods require extended times for purification, up in the range of 96 hours. Those methods also ineffectively cure the melt, as lower portions of the melt are never purified.
During melt purification, impurities react with the gas molecules and exit the melt in a gaseous phase. Some impurities react and precipitate from the melt as a sludge. Other reacted impurities float to the surface.
Needs exist for purification systems that remove impurities faster and more efficiently.
These problems and many more remain in the present practices. Needs exist for new approaches for crystal material purification and the crystal growth processes.
Purifying of crystals by reactant gas contact in current systems results in delays and adds significant times to the crystal growth process.
SUMMARY OF THE INVENTION
Reactive gas is released through a crystal source material or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants are added to the melt. The melt moves away from the heater and the crystals formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated under pressure for heat treating and annealing.
The invention provides multi zone plate crystal growth and purifying.
The new continuous feed multi-zone crystal grower is capable of growing crystals with very large dimensions under reactive atmospheres. The invention produces high purity crystals with very uniform doping concentrations regardless of the crystal size. The dopant level and the residual impurities are controlled in situ within the crystal feed chamber and during the crystal growth process. Crystal applications include nuclear medicine, high energy physics, optics and others where economical production of high purity and large size crystals are required.
The invention provides horizontal (or inclined under some angle) continuous crystal growth process for plates of any dimensions.
Reactive gas permeates start-up material, crystal powder or polycrystalline material or a crystal melt.
Stoichiometry control or “repair” of start-up material is achieved using the present invention.
Multi-zone traveling, stationary immersed and non-immersed heaters, resistive and RF heating elements, or other type heaters are used. This allows controlled gradient crystal growth of any size crystals.
A traveling crucible or crystal slab can be used if the heaters are stationary.
The present invention can be attached as a module to heaters for in situ purification and dopant control.
Dopant concentration control can be achieved by adding dopant in solid or gaseous form. If excess dopant has to be controlled, the excess is either neutralized via chemical reaction or by dilution with pure melt.
For very high purity crystals or crystals with very large sizes, residual impurities control can be achieved by removing the melt from one of the molten zones via vacuum suction and melt draining.
High temperature and high pressure annealing of the plates in final sizes enhances the crystal quality properties.
The invention eliminates cutting of at least one dimension of the crystal before further processing.
A preferred continuous crystal plate growth apparatus has a source of starter material. A valve supplies material from the starter material source. A first, hot zone communicates with the valve for heating the material. A dopant source and a dopant controller are connected to the hot zone for supplying dopant into the material in the hot zone. A second reduced heat zone beyond the hot zone reduces heat in the material, which forms a solid plate. A receiver receives the solid plate from the second, reduced heat zone and advances the solid plate. A lowered temperature heating zone adjacent the receiver lowers temperature of the solid crystal plate on the receiver. An enclosure encloses the zones and the solid crystal plate in a controlled gaseous environment.
A large heater overlies the small heater. The large heater has first and second zones, and the small heater has the first hot and second reduced heat zones. Baffles separate the first and second zones of the heaters.
The first zone of the small heater produces a crystal melt temperature higher than a crystal melting temperature in the material. The second zone of the small heater produces a temperature lower than the melting temperature. The temperature in the material at the small heater baffle is about the melting temperature. The large heater first zone provides heat below the melting temperature, and the large heater second zone provides a lower heat.
Preferably the receiver is a conveyor which moves at a speed equal to a crystal growth rate.
A second source of starter material and a second valve are connected to the hot zone for flowing material from the second source to the hot zone.
The crystal melt or starter material is purified in a chamber having a bottom and sides. A lid covers the chamber. An opening introduces liquid or solid material into the chamber. An outlet near the bottom of the chamber releases crystal melt or starter material from the chamber. A shut-off valve opens and closes the outlet. A source of reactive gas is connected to the chamber and extends into a bottom of the chamber. A reactive gas release barrier near the bottom of the chamber slowly releases reactive gas into the crystal starter material. A gas space is located at the top of the chamber above the crystal melt or starter material. An exhaust line is connected to the space at the top of the chamber for withdrawing gas from the top of the chamber. A heater adjacent the chamber heats the chamber and the crystal melt or starter material within the chamber.
The heater has heating elements around sides of the chamber and along the walls of the chamber.
The shut-off valve is a thermally activated or a mechanical or electromechanical valve.
An inlet conduit is connected to the lid. A source of reactive liquid or solid is connected to the inlet conduit. A valve is connected between the source of reactive liquid or solid. A plug is connected to the conduit for plugging the conduit after adding reactive liquid or solid to the chamber.
Preferably a vacuum pump is connected to the exhaust line. A preferred barrier is a porous plate.
In one heating and purifying embodiment, a chamber has an inlet and an outlet. A purified material discharge is connected to the outlet. An enclosure has side walls, a bottom and a top. A reactive gas source is connected to a gas inlet tube. A gas distributor is mounted in the chamber near the bottom. A gas releasing plate connected to the gas distributor releases the reactive gas from the inlet tube and the distributor into the material in the feeding and purifying chamber. A heater heats material in the chamber. A gas exhaust exhausts gas from an upper portion of the chamber.
A preferred casing has a cover and side walls, and the casing side walls include the chamber side walls.
In one embodiment, an upper heater has heating elements across a top of the chamber.
The apparatus moves with respect to a stationary base for supporting a growing crystal.
Preferred crystal growth embodiments have a support for supporting a growing crystal. A first zone heater adjacent the growing crystal heat and liquefies the growing crystal. A second zone heater spaced from the first zone heater along the growing crystal re-liquefies the growing crystal. Preferably multiple zone heaters are spaced from each other along the growing crystal for sequentially liquefying the growing crystal. Preferably the first zone heater further includes heating and purifying apparatus for purifying the crystal melt. A preferred first zone heater includes a reactive gas distributor for distributing reactive gas from near a bottom of the crystal melt.
A liquid or solid adaptive substance source releases liquid or solid reactive substance into the melt.
A source of dopant is connected to the last zone heater for supplying dopant into the crystal melt.
In one embodiment the support is a movable support for moving the liquid crystal along zone heaters. Alternatively, the zone heaters move along the crystal.
One crystal growth embodiment has a chamber for holding a crystal melt. A crystal support holds a crystal movable with respect to the chamber for forming a bottom of the chamber with the crystal. A first heater adjacent the chamber heats and maintains a crystal melt within the chamber. A baffle is connected to the first heater adjacent a bottom of the chamber. A second heater is connected to the baffle beyond the first heater. A source of reactive gas feeds a gas tube connected to a controller. A distributor is connected to the gas tube and is mounted in the chamber for positioning within the crystal melt. A gas releaser connected to the distributor releases reactive gas into the crystal melt. A gas exhaust is connected to the chamber exhausts gas from the chamber above the crystal melt. An inlet tube and a controller release reactant substance into the chamber and into the crystal melt. A dopant conduit and a dopant source provide a dopant from the source through the conduit to the chamber. The reactive substance and the reactive gas control the dopant.
These and further and other objects and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification, with the claims and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an apparatus and process for continuous crystal plate growth.
FIG. 2 shows a chamber for purifying crystal material and liquid or solid scavengers. The crystal material may be a starter powder or a crystal melt. The purifier in FIG. 2 may be used to supply the continuous crystal plate growth apparatus and process shown in FIG. 1 .
FIG. 3 shows a crystal melt purifier for use in a continuous crystal plate growth apparatus and process, such as shown in FIG. 1 .
FIG. 4 shows a continuous crystal plate growth apparatus and process using multiple zone heating and purifying.
FIG. 5 is a detail of sides of the crystal growth apparatus in the melt zones.
FIG. 6 shows varied heaters for use in the continuous heat crystal growth process.
FIG. 7 shows the use of the present purifying apparatus and process in a vertical Bridgeman crystal growth system.
FIG. 8 is a schematic representation of the heat treating and annealing of a cut crystal before use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, a crystal 1 is grown in a continuous process by first purifying a crystal source material, which is a crystal melt or powder, in a purification station 3 , as later will be described. A second purification station 5 may be provided so that the crystal melt or powder may be prepared in a batch process within alternating stations, which may number several stations.
Valves 7 control the flow of purified crystal melt or purified crystal source powder 9 to a first hot zone 11 of a first heater 13 . The first hot zone 11 has a temperature which is above the melt temperature of the crystal. A boat-shaped container holds the liquefied crystal 15 .
A dopant source 17 has a controller 19 which controls the dopant added to the liquefied crystal 15 .
The first heater 21 surrounding the first hot zone 11 produces a heat above the melting temperature of the crystal. A baffle 23 next to the first heater separates the first heat zone 11 from the second heat zone 25 . The second heater 27 which surrounds the second zone produces a temperature in the second zone which is below the melt temperature of the crystal, so that a crystal solid interface 29 exists in the vicinity of the baffle between the liquefied crystal 15 and the formed crystal 1 . The liquefied crystal, the liquid solid interface and the first portion of the crystal are supported in a boat-shaped crucible container with a bottom 31 and side walls which support the crystal. As the crystal leaves the support plate 31 it passes on to a conveyor 33 with supporting rollers 35 , which continually move the crystal away from the first heater. The crystal moves within an enclosure 43 , which has a noble gas or noble gas and reactant gas atmosphere 45 .
A large heater has a first zone 37 which heats the initial part of the crystal apparatus to a temperature below the melt temperature, and a second zone 39 which maintains the crystal at a lower temperature.
A purified and doped crystal emerges from the enclosure.
In one example, as shown in the chart at the bottom of FIG. 1, when using the continuous crystal growth apparatus and process to grow a doped sodium iodide crystal, the first hot zone is maintained at about 700° C. The temperature at the baffle is maintained at the melting point of the material, which in the case of the sodium iodide crystal is about 661° C., or cesium iodide about 621° C. The second zone of the first heater maintains a temperature of about 550° C., or below the temperature of melting. The larger heater 41 has two zones 37 and 39 , which provide heat below the temperature of zone 25 , or at about 450° C. and about 400° C. respectively, so that the crystal uniformly cools as it proceeds.
As shown in FIG. 2, a crystal purifying apparatus and process is generally referred to by the numeral 51 . The apparatus has a chamber 53 , which is preferably a quartz chamber, for holding a crystal melt 55 , or alternatively for holding crystal-forming powder used to create a crystal melt. The chamber has a lid 57 , which may be a quartz lid, which tightly seals with upper edges of the walls 59 of the chamber 53 . A reactive gas source 61 is controlled by a valve 63 , which supplies reactant gas to a pipe 65 . Tubes 67 conduct the reactant gas to a distributor 69 at or near the bottom 71 of the chamber 53 . As shown in FIG. 2, the distributor may be a plenum. Gas is released from the plenum through a gas release plate 73 , which in this case may be a porous quartz plate. Positive reactant gas pressure is maintained within the plenum 69 so that the gas flows upward through the port plate 73 . A suitable reactant gas, for example, may be bromine mixed with argon or helium or a noble gas. The entire gas mixture is called the reactant gas, although only the bromine may be actually reactant. Bromine, for example, may form gaseous bromides which are removed as gases from the melt or powder 55 .
The flow of gas through the melt or powder is represented by the gas pockets or bubbles 75 , which move upward. The flow of gas also entrains any water in the crystal material and carries the water from the heated crystal material as gaseous water vapors which are removed from the space 77 at the top of the chamber through a reduced pressure line 79 or vacuum line, which is connected to a source of reduced pressure or a vacuum 81 , as controlled by a valve 83 . The vacuum line 79 withdraws water vapor and reacted gas products. Solid impurities fall to the bottom of the material 55 when the material is in melt, and light solid impurities migrate upward to float on the top of the melt. Heaters, generally indicated by the numeral 85 , surround the chamber.
The heaters 85 heat the powder material or maintain the high temperature necessary for melting and maintaining the melt 55 . At the top of the heaters a large insulating block 89 is placed to maintain the uniform temperature within the apparatus.
A source 91 of liquid or solid reactant substance is controlled by a controller 93 for supply to a conduit 95 , which extends through the insulation 89 and lid 57 to an opening 97 , which is controlled by a removable plug 99 , so that the appropriate scavenging liquid or solid may be added to the melt 55 .
The purified liquid or powder is removed through an outlet 101 in a side wall of the chamber 53 slightly above the bottom.
A shut-off valve is used in the supply line 101 . The shutoff valve may be a mechanical valve or an electromechanical solenoid operated valve, or a thermally operated valve 103 , such as shown in FIG. 2 . The thermally operated valve is a series of cooling and heating coils which freeze or melt the crystal and allow flow of liquid crystal through the conduit 101 .
FIG. 3 shows an alternate heating and purifying apparatus and process in which a crystal melt 55 is held between side walls 105 and the base 107 of a casing 109 , which has a cover 111 . An upper heater 113 encloses the crystal melt. Insulation layers 115 above the upper heater 113 concentrate and reduce outward flow of the heat.
Reactant gas from a source 61 is admitted through a control valve 33 to a reactant gas tube 67 , and from there into a distributor plenum 69 within a distributor housing 117 . A porous quartz plate 73 covers the distributor and releases gas in the form of bubbles 75 through the melt 55 .
Gaseous reactant products and water vapor escape through small openings 119 , which extend through the heater 113 , the insulation 115 and the cover 111 . Large openings 119 may be supplied for the addition of liquid or solid reactant substances or dopants.
FIG. 4 shows a multiple heater arrangement 121 for zone heating and liquefaction 123 , 125 and 127 as the crystal 1 moves in the direction 131 with respect to the zone heaters 133 , 135 and 137 . The sequential melting of the crystal further purifies the crystal. In the final melting operation, such as in heating and purifying apparatus 137 , the dopant is added to the crystal.
The crystal may move through the assembly of heating and purifying apparatus such as on a support 141 , which is part of a conveyor 143 supported by rollers schematically indicated at 145 . Preferably, as shown in FIG. 5, in the areas of the melt zones 123 , 125 and 127 , the liquefied crystal is supported within a boat-shaped trough 147 with a base 148 and side walls 149 , which are formed of quartz or ceramic. As the molten material solidifies and crystallizes, the individual crystal portions may be picked up by conveyors, or the entire crystal 1 may move along a rigid and smooth quartz or ceramic surface of a support 141 .
Alternatively, the heating and purifying assemblies 133 , 135 and 137 may be constructed for movement along a stationary crystal.
FIG. 6 shows three configurations of heating and purifying apparatus shown melting and purifying a crystal. The heaters may be used sequentially as different heaters, or each of the heaters in a sequence may be identical. Heating element 151 has an upper heater 153 and a lower heater 155 , which melt the crystal 1 as it flows between the heating elements. The heating and purifying apparatus 157 has an upper heater 158 and side heaters 159 . The bottom 161 may be opened so that the crystal or heater may move and so that the melted crystal may be uniformly supported through the heating area. Alternatively, the heating elements may extend entirely around the liquid crystal area.
Heater 163 radiates heat downward from a thermal radiator 165 , such as a quartz heating element or a wide laser beam, or a series of laser beams, or simply a strong standard heater. The heat flux 167 heats and melts the crystal material.
As shown in heating and purifying elements 151 and 157 , the height of the heater openings may be equal or larger than the melt thickness. Alternatively, the opening 169 may be smaller than the melt thickness so that the crystal moves faster through the melt zone than through the approach. In one example, such as when melting and purifying a sodium iodide crystal in multiple melting zones, the crystal may move at a speed of slightly less than one foot per day.
As shown in the FIG. 7, the present purifying apparatus and process may be used in a standard Bridgeman crystal growth apparatus 171 . An upper heater 173 heats a zone 175 around melt chamber 177 to a temperature above the melting temperature. A baffle below heater 173 separates heat zone 175 from heat zone 179 , in which heat from a heater 181 is below the melting temperature of the crystal. A liquid-solid interface 183 of the crystal occurs at about the position of the baffle 185 . Reactant purifying gas is admitted to the melt 187 through a source 61 and a control 63 , and a tube 65 leading to a distributor 69 , which releases reactant gas through a porous plate into the crystal melt 187 . Gasified impurities are removed through vacuum line 179 , as controlled by valve 83 to a source of reduced pressure 81 . The crystal 191 is contained in a platinum or quartz crucible 193 .
As shown in FIG. 8, the final product, which is a crystal 201 which has been cut from the long crystal plate, is placed in a support 203 on a substrate 205 , and sides and end surfaces are covered by plates 207 and a cover 209 is placed over the crystal. All of the entire system is enclosed. The entire system is enclosed in a crystal furnace 211 that provides the necessary temperature for the heat treating an annealing process while force is applied to the crystal 201 through the cover and walls 209 and 207 .
While the invention has been described with reference to specific embodiments, modifications and variations of the invention may be constructed without departing from the scope of the invention, which is defined in the following claims.
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Reactive gas is released through a crystal source material or melt to react with impurities and carry the impurities away as gaseous products or as precipitates or in light or heavy form. The gaseous products are removed by vacuum and the heavy products fall to the bottom of the melt. Light products rise to the top of the melt. After purifying, dopants are added to the melt. The melt moves away from the heater and the crystal is formed. Subsequent heating zones re-melt and refine the crystal, and a dopant is added in a final heating zone. The crystal is divided, and divided portions of the crystal are re-heated for heat treating and annealing.
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This application is a continuation of Ser. No. 10/215,400, filed Aug. 8, 2002, now abandoned.
FIELD OF THE INVENTION
The present invention relates to sulfonyl-containing 3,4-diaryl-3-pyrrolin-2-ones, especially to new compounds of the general formula (I), to a process for their preparation, to pharmaceutical compositions containing such compounds, and to the medical use thereof in the treatment of diseases relating to the inhibition of cyclooxygenase-2 (COX-2), wherein general formula (I) is:
wherein R 1 is 4-methylsulfonyl, 4-aminosulfonyl, hydrogen, 2-, 3-, or 4-halogen, including F, Cl or Br, C 1 –C 6 -alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl;
R 2 is 4-methylsulfonyl, 4-aminosulfonyl, hydrogen, 2-, 3-, or 4-halogen, C1–C6-alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl; R 3 is hydrogen, methyl, ethyl, n-propyl, i-propyl, c-propyl, n-butyl, isobutyl. With the proviso that R 1 is a methylsulfonyl or aminosulfonyl, R 2 is any one group as defined above except a methylsulfonyl or aminosulfonyl group; when R 1 is a methylsulfonyl or aminosulfonyl, R 2 is any one group as defined above except a methylsulfonyl or aminosulfonyl group.
The halogen of this invention is F, Cl and Br.
TECHNICAL BACKGROUND
Non-steroidal anti-inflammatory drugs (NSAIDs) are used extensively for the treatment of inflammatory conditions, including pain-releasing, anti-pyretic and rheumatoid arthritis. These functions are believed to inhibit the enzyme cyclooxygenase (COX) that is involved in the biosynthesis of prostaglandins G and H from arachidonic acid. So far two isozymes of COX are known: COX-1 and COX-2. COX-1 is constitutively produced in a variety of tissues and appears to be important to the maintenance of normal physiological functions, including gastric and renal cytoprotection. The COX-2 is an inducible isozyme, which is produced in cells under the stimulation of endotoxins, cytokines, and hormones and catalyzes the production of prostaglandins which cause inflammation.
The currently therapeutic use of NSAIDs has been associated with the inhibition of both COX-1 and COX-2 and causes well-known side effects at the gastrointestinal and renal level. Therefore, the selective COX-2 inhibitors could provide anti-inflammatory agents devoid of the undesirable effects associated with classical, nonselective NSAIDs. In addition, COX-2 is over-expressed in colon cancer tissue. COX-2 inhibitors possess potential prophylactic and therapeutic application to colon cancer.
The COX-2 inhibitors as selective anti-inflammatory drugs are chemically aminosulfonylaryl or methylsulfonylaryl-containing substances, such as Nimesulide (R. H. Brogen and A. Ward. Drugs, 1998, 36: 732–753), NS-398 (JP 292856, JP 871119), Meloxicom(DE 2756113, DE 771216), pyrrazole-containing tricyclic compounds, for example, Celecoxib(WO 9641825, WO 961227), oxazole-containing tricyclic compounds, for example, JRE-522(EP 745598, EP 961204), unsaturated gamma-lactone-containing compounds, for example, Rofecoxib (EP 788476, WO 9613483). The non-selective NSAID Indomethacin as a lead compound was chemically modified to give rise to selective COX-2 inhibitors without sulfonyl groups, for example L-748780 and L-761066 (W. C. Black et al. Bioorg Med. Chem. Lett. 1996, 6: 725–742, WO 9730030). These compounds exhibit a selective COX-2 inhibition to different extents, and constitute a group of anti-inflammatory drugs with little adverse reactions. Reports on the sulfonyl-containing 3,4-diphenyl-2,5-dihydropyrrolyl-2-ones and their inhibitory properties for COX-2 has not been found so far in the pharmacological literature.
SUMMARY OF THE INVENTION
In one aspect, the present invention is to provide compounds of sulfonyl-containing 3,4-diaryl-3-pyrrolin-2-ones of general formula (I), as shown below.
In another aspect the present invention is to provide methods of preparing the compounds of sulfonyl-containing 3,4-diaryl-3-pyrrolin-2-ones.
In an additional aspect the present invention provides pharmaceutically acceptable compositions which comprise a therapeutically effective amount of one or more of the compounds of formula (I), as described herein, formulated together with one or more pharmaceutically acceptable carriers.
In a further aspect the present invention provides an application of the compounds of formula (I) to the diseases relevant to COX-2.
In order to complete the purpose of the present invention, the following technique is performed:
This invention encompasses compounds of formula (I)
wherein R 1 is 4-methylsulfonyl, 4-aminosulfonyl, hydrogen, 2-, 3-, or 4-halogen, including F, Cl or Br, C 1 –C 6 -alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl;
R 2 is 4-methylsulfonyl, 4-aminosulfonyl, hydrogen, 2-, 3-, or 4-halogen, C1–C6-alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl; R 3 is hydrogen, methyl, ethyl, n-propyl, i-propyl, c-propyl, n-butyl, isobutyl. With the proviso that R 1 is a methylsulfonyl or aminosulfonyl, R 2 is any one group as defined above except a methylsulfonyl or aminosulfonyl group; when R 1 is a methylsulfonyl or aminosulfonyl, R 2 is any one group as defined above except a methylsulfonyl or aminosulfonyl group.
The halogen of this invention is F, Cl and Br.
Specifically, the present invention comprises the compounds of formula (I), wherein the alkyl of R 1 is a methyl or ethyl group, and the alkoxy of R 1 is a methoxy group; the alkyl of R 2 is a methyl or ethyl group, and the alkoxy of R 2 is a methoxy group; and R 3 is selected from hydrogen, methyl, ethyl, n-propyl, i-propyl or cyclo-propyl.
A synthetic method was disclosed in the literature (P. Babu and T. R. Balasubramanian, J Indian Chem. 1987, 26B: 63) for preparing 3,4-diaryl-3-pyrrolin-2-ones. The method involves condensation of a substituted alpha-bromo-acetophenone with a phenacetamide to form phenacetamido-acetophenone, which is cyclized in triethlamine and acetonitrile on heating to give a diphenyl=dihydropyrrolones. However, this method accompanies production of by-products and restricts synthesis of the compounds with various substituents.
To prepare the compounds of formula (I) defined in this invention, the synthetic method comprises a substitution reaction of a substituted styrene oxide with ammonia or a primary amine at different temperature and various solvents. The resulting amino alcohol, under a controlled condition, reacts with a substituted phenacetyl chloride. Instead of esters, the predominating products of this reaction are amides owing to stronger nucleophibility of amino than that of hydroxy group. The secondary hydroxy group of hydroxy-amines is oxidized using Jone's reagent to give keto-amides, which under an alkali catalysis are cyclized to yield the compounds of the present invention.
Specifically, the method for preparing compounds of formula (I), where R 1 stands for 2-, 3-, or 4-substituted groups except methylsulfonyl or aminosulfonyl moieties, R 2 represents 4-methylsulfonyl or 4-aminosulfonyl groups, and R 3 is the same as the above-mentioned components, comprises the following steps of:
For the compounds of formula (I) where R 1 stands for 4-methylsulfonyl or 4-aminosulfonyl groups R 2 represents 2-, 3-, or 4-substituted groups except methylsulfonyl or aminosulfonyl moieties, and R 3 is the same as the above-mentioned substituents, comprises the following steps of:
The synthetic feature of above-mentioned schemes is described as follows:
(A) An aminosulfonyl or methylsulfonyl-substituted styrene oxide reacts with a primary amine in a lower alkyl alcohol medium at the temperature from 0□ to 60□, to give rise to N-alkyl-beta-hydroxy-aminosulfonyl(or methylsulfonyl)phenethyl amine; (B) the resulting N-alkyl-beta-hydroxy-aminosulfonyl(or methylsulfonyl)phenethyl amine is acylated by a phenactyl chloride with optional substituent(s), selected from hydrogen, 2-, 3-, or 4-halogen, C 1 –C 6 -alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl, at room temperature, yielding N-alkyl-N-[2-hydroxy-2-(aminosulfonyl(or methylsulfonyl)phenyl)ethyl-4-substituted pheacetamides; (C) using Jone's reagent or pyridine-chromic anhydride solution the N-alkyl-N-[2-hydroxy-2-(aminosulfonyl(or methylsulfonyl)phenyl)ethyl-4-substituted pheacetamides are oxidized to give N-alkyl-N-[2-oxo-2-(aminosulfonyl(or methylsulfonyl)phenyl)ethyl-4-substituted pheacetamides; (D) under the catalysis of potassium or sodium lower alkyl alcoholate the N-alkyl-N-[2-oxo-2-(aminosulfonyl(or methylsulfonyl)phenyl)ethyl-4-substituted pheacetamides cyclize to the title compounds of the present invention.
The present invention provides pharmaceutically acceptable compositions comprising a therapeutically effective amount of one or more of the compounds defined in formula (I).
Pharmacological study reveals that the compounds of formula (I) of the present invention possess inhibitory activity against cyclooxygenase-2, which is produced by the mediation of inflammatory substances; the compounds of formula (I) significantly block mice ear edema induced by carrageenan. More importantly, the inhibitory concentration of compounds of formula (I) against COX-2 does not show any inhibition of COX-1, but shows that the compounds are selectively used for the inhibition of COX-2 or for treatment of COX-2 mediated diseases, especially in the long-term clinical application the compounds of formula (I) would exhibit less adverse reactions, such as less side effects for gastrointestinal and renal organs.
The compounds of formula (I) are useful for relief of pain, fever, inflammation of a variety of conditions including rheumatic fever, symptoms associated with common cold, headache. In addition COX-2 enzyme is highly-expressed in colon and rectum carcinoma, and compounds of formula (I) may inhibit cellular neoplastic transformations and hence can be used in the treatment of colon and rectum cancer.
The typical compounds of the present invention preferably include, but are not limited to:
N-methyl-3-(4-methylsulfonylphenyl)-4-(4-phenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-methylsulfonylphenyl)-4-(4-chlorophenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-methylsulfonylphenyl)-4-(4-fluorophenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-methylsulfonylphenyl)-4-(4-chlorophenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-aminosulfonylphenyl)-4-(4-phenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-aminosulfonylphenyl)-4-(4-chlorophenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-methylsulfonylphenyl)-4-(4-methylphenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-methylsulfonylphenyl)-4-(4-methylphenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-methylsulfonylphenyl)-4-(4-fluorophenyl)-2,5-dihydropyrrole-2-one; N-cycopropyl-3-(4-methylsulfonylphenyl)-4-(4-chlorophenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-methylsulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-methylsulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-methylsulfonylphenyl)-4-(4-bromophenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-pheny-4-1(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one; N-cycopropyl-3-pheny-4-1(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-chlorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(3-chlorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-bromophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one; N-methyl-3-(4-fluorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-aminosulfonylphenyl)-phenyl-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one; N-propyl-3-(4-aminosulfonylphenyl)-phenyl-4-(3-bromophenyl)-2,5-dihydropyrrole-2-one; and N-cycopropyl-3-(4-aminosulfonylphenyl)-phenyl-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one.
According to the present invention, a pharmaceutical composition containing effective amounts of the compounds of claim 1 and pharmaceutically acceptable carriers is provided.
The present invention is also related to a method for treating inflammatory disease of mammalian animals including humans, by administration of effective amounts of the compounds of formula (I) to a subject.
Preferably, the compounds of the present invention can be administered to a patient in such oral dosage forms as tablets, capsules, pills, or lozenges. Likewise, administration may be effected through parenteral route, such as injection or suppository. All these dosage forms are known to those of ordinary skill in the art or can be determined by routine experimentation. To manufacture tablets, capsules or lozenges, non-toxic pharmaceutically acceptable excipients may be, for example, inert diluents, such as starch, gelatin, acacia, silica, and PEG. Solvents for liquid dosage forms comprise water, ethanol, propylene glycol, vegetable oils such as corn oil, peanut oil and olive oil. Auxiliary components in the dosage forms of the present invention comprise surface active agents, lubricates, disintegrators, sweeteners, disinfectants, and coloring agents.
The amount of active ingredient that may be combined with the carrier and auxiliary materials in a single dosage form will vary depending on the host treated and the particular mode of administration. For example, a formulation intended for the oral administration of patients may contain from about 10 mg to 500 mg of a compound of formula (I). An optimal dosage form typically contains 20 mg to 100 mg of a compound of formula (I).
The following non-limiting examples further describe and illustrate details for the preparation of the compounds of the present invention. The examples are illustrative and do not restrict the scope of the present invention. Those skilled in the art will readily understand and appreciate that known variations of the conditions and procedures in the following preparative methods can be utilized. In these examples, all temperatures are indicated by degrees Celsius, and melting points are uncorrected. Some of the following examples further include nuclear magnetic resonance (H-NMR) data for the subject compounds.
DETAILED DESCRIPTION OF THE INVENTION
Preparation of N-alkyl-β-hydroxy-substituted phenethylamines
EXAMPLE 1
N-Methyl-β-hydroxy-4-methyl-phenethylamine
4-Methyl styrene oxide(1.0 g, 8.0 mmol) and 3 ml of methylamine in methanolic solution(28%) were charged into a flask. The flask was sealed and put in a refrigerator for 5–7 days. The solution was concentrated and the residue crystallized from ether, the title compound was obtained as white needle crystals, mp. 90.5–93.2° C., yield 71.2%.
EXAMPLE 2
N-Methyl-β-3-hydroxy-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material is styrene oxide (0.96 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 75.0–76.0° C., yield 58.2%.
EXAMPLE 3
N-Methyl-β-hydroxy-4-fluoro-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material is 4-fluoro-styrene oxide (1.11 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 77.0–78.8° C., yield 87.7%.
EXAMPLE 4
N-Methyl-β-hydroxy-4-chloro-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material was 4-chloro-styrene oxide(1.24 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp.84–86° C., yield 31.6%.
EXAMPLE 5
N-Methyl-β-hydroxy-4-bromo-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material was 4-bromo-styrene oxide (1.59 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp.91.5–93.7° C., yield 85.7%.
EXAMPLE 6
N-Methyl-β-hydroxy-3-fluoro-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material is 3-fluoro-styrene oxide (1.11 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp.63–65° C., yield 32.1%.
EXAMPLE 7
N-Methyl-β-hydroxy-3-chloro-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material was 3-chloro-styrene oxide(1.24 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp.95.5–97° C., yield 55.8%.
EXAMPLE 8
N-Methyl-β-hydroxy-3-bromo-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material was 3-bromo-styrene oxide (1.59 g) instead of 4-methyl styrene oxide. The title compound was obtained as white needle crystals, mp.112.–113.5° C., yield 67.0%.
EXAMPLE 9
N-Propyl-β-hydroxy-4-methyl-phenethylamine
4-Methyl styrene oxide(1.0 g,8.0 mmol)and 3 ml of propylamine in methanolic solution were charged into a flask. The flask was sealed and put in a refrigerator for 5–7 days. The solution was concentrated and the residue crystallized from ether, the title compound was obtained as white needle crystals, mp. 73.0–75.1 C, yield 49.6%.
EXAMPLE 10
N-Propyl-β-hydroxy-4-fluoro-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 4-fluoro-styrene oxide (1.11 g) instead of 4-Methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 58.6–78.8° C., yield 74.1%.
EXAMPLE 11
N-Propyl-β-hydroxy-3-chloro-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 3-chloro-styrene oxide (1.24 g) instead of 4-Methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 79.5–80.5° C., yield 31.6%.
EXAMPLE 12
N-Propyl-β-hydroxy-4-bromo-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 4-bromo-styrene oxide (1.59 g) instead of 4-Methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 72.5–74.5° C., yield 64.6%.
EXAMPLE 13
N-Propyl-β-hydroxy-3-fluoro-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 3-fluoro-styrene oxide (1.11 g) instead of 4-Methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 46–47.3° C., yield 31.9%.
EXAMPLE 14
N-Propyl-β-hydroxy-3-chloro-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 3-chloro-styrene oxide (1.24 g) instead of 4-Methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 69.5–71.0° C., yield 50.9%.
EXAMPLE 15
N-Propyl-β-hydroxy-3-bromo-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 3-bromo-styrene oxide (1.59 g) instead of 4-Methyl styrene oxide. The title compound was obtained as white needle crystals, mp. 79.7–81.4° C., yield 80.5%.
EXAMPLE 16
N-Cyclopropyl-β-hydroxy-4-chloro-phenethylamine
4-Chloro styrene oxide (1.24 g, 8.0 mmol) and 3 ml of cyclopropylamine in methanolic solution were charged into a flask. The flask was sealed and put in a refrigerator for 5–7 days. The solution was concentrated and the residue crystallized from ether, the title compound was obtained as white needle crystals, mp. 100.2–102° C., yield 54.5%.
EXAMPLE 17
N-Cyclopropyl-β-hydroxy-4-bromo-phenethylamine
The procedure was in the same manner as described in example 16, except that the starting material was 4-bromo-styrene oxide (1.59 g) instead of 4-chloro styrene oxide. The title compound was obtained as white needle crystals, mp. 105.4–107.4° C., yield 79.4%.
EXAMPLE 18
N-Cyclopropyl-β-hydroxy-3-fluoro-phenethylamine
The procedure was in the same manner as described in example 16, except that the starting material was 4-fluoro-styrene oxide(1.11 g) instead of 4-chloro styrene oxide. The title compound was obtained as white needle crystals, mp. 57.8–60.0° C., yield 31.6%.
EXAMPLE 19
N-Cyclopropyl-β-hydroxy-3-chloro-phenethylamine
The procedure was in the same manner as described in example 16, except that the starting material was 3-chloro-styrene oxide(1.24 g) instead of 4-chloro styrene oxide. The title compound was obtained as white needle crystals, mp. 71.3–73.2° C., yield 62.0%.
EXAMPLE 20
N-Cyclopropyl-β-hydroxy-3-bromo-phenethylamine
The procedure was in the same manner as described in example 16, except that the starting material was 3-bromo-styrene oxide(1.59 g) instead of 4-chloro styrene oxide. The title compound was obtained as white needle crystals, mp. 69.5–70.4° C., yield 62.7%.
EXAMPLE 21
N-Methyl-β-hydroxy-4-methylsulfonyl-phenethylamine
The procedure was in the same manner as described in example 1, except that the starting material was 4-methylsulfonyl-styrene oxide (1.58 g) instead of 4-methyl styrene oxide. The title compound was obtained as white crystals, mp. 110–112 C, yield 57.0%.
EXAMPLE 22
N-Propyl-β-hydroxy-4-methylsulfonyl-phenethylamine
The procedure was in the same manner as described in example 9, except that the starting material was 4-methylsulfonyl-styrene oxide (1.58 g) instead of 4-methyl styrene oxide. The title compound was obtained as white solid, mp.120–123° C., yield 85.0%.
EXAMPLE 23
N-Cyclopropyl-β-hydroxy-4-methylsulfonyl-phenethylamine
The procedure was in the same manner as described in example 16, except that the starting material was 4-methylsulfonyl-styrene oxide(1.58 g) instead of 4-chloro styrene oxide. The title compound was obtained as white solid, yield 70.0%.
Preparation of Methylsulfonyl (or Aminosulfonyl)Phenacetyl Chlorides
EXAMPLE 24
4-Methylsulfonyl (or Aminosulfonyl)Phenacetyl Chloride
A mixture of 1.5 mmol of 4-methylsulfonyl (or aminosulfonyl)phenacetic acid and 5 ml of thionyl chloride was heated under reflux and in nitrogen atmosphere to give a clear solution. Removal of the excess of thionyl chloride under reduced pressure a light yellow solid was obtained and without purification put into the next reaction.
Preparation of N-alkyl-N-2-hydroxy-2-substituted phenyl ethyl-4-methyl(amino) sulfonyl)phenacetamides
EXAMPLE 25
N-Methyl-N-(2-hydroxy-phenylethyl-4-methylsulfonylphenacetamide
To a solution of 1.5 mmol of N-methyl-β-hydroxy-phenethylamine described in Example 2 in 20 ml of re-distilled THF was added with stirring 4.5 mmol of triethylamine in nitrogen atmosphere. To the mixture was rapidly added a solution of 1.5 mmol of 4-methylsulfonyl phenacetyl chloride (Example 24)in 10 ml of redistilled THF. The resulting white precipitate was filtered off. The filtrate was evaporated and the residue was purified by column chromatograph on silica gel (eluent:ethyl acetate:methyle chloride—1:2–3) to give white solid, mp. 160–161° C., yield: 90.0%.
EXAMPLE 26
N-Propyl-N-[2-hydroxy-2-(4-methylphenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in Example 25, except that the starting material was N-propyl-β-hydroxy-4-methylphenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained yield 46.5%.
EXAMPLE 27
N-Methyl-N-[2-hydroxy-2-(4-methylphenyl]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in Example 25, except that the starting material was N-methyl-β-hydroxy-4-methylphenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as white solid, yield 44.0%.
EXAMPLE 28
N-Propyl-N-[2-hydroxy-2-(4-fluorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-propyl-β-hydroxy-4-fluorophenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as white solid, 51.4%.
EXAMPLE 29
N-Cyclopropyl-N-[2-hydroxy-2-(4-chlorophenyl]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-cyclopropyl-β-hydroxy-4-chlorophenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as white solid, 51.4%.
EXAMPLE 30
N-Cyclopropyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-cyclopropyl-β-hydroxy-3-chlorophenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The obtained title compound was used directly into the oxidation reaction of the next reaction.
EXAMPLE 31
N-Methyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-methyl-β-hydroxy-3-chlorophenethylamine prepared in Example 4 instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as white solid, mp. 207–208° C., yield 89.5%.
EXAMPLE 32
N-Propyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-n-propyl-β-hydroxy-3-chlorophenethylamine prepared in Example 11 instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as white solid, mp. 124–125° C., yield 90.0%.
EXAMPLE 33
N-Methyl-N-[2-hydroxy-2-(3-bromophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-methyl-β-hydroxy-3-bromophenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as light yellow oil, yield 45.4%.
EXAMPLE 34
N-Cyclohexyl-N-(2-hydroxy-2-phenyl)ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material was N-cyclohexyl-β-hydroxy-2-phenethylamine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as light yellow oil, yield 55.6%.
EXAMPLE 35
N-Cyclopropyl-N-[2-hydroxy-2-(3-fluorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting material is N-cyclopropyl-β-hydroxy-2-(3-flurophenethyl)amine instead of N-methyl-β-hydroxy-phenethylamine. The title compound was obtained as light yellow oil, yield 47.3%.
Preparation of N-alkyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-substituted phenacetamides
EXAMPLE 36
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide
To a solution of 1.5 mmol of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine described in Example 21 in 20 ml of pyridine was added with stirring phenacetyl chloride in nitrogen atmosphere. The mixture was stirred at room temperature until the reaction was completed. The resulting white precipitate was filtered off. The filtrate was evaporated and the residue was purified by column chromatograph on silica gel (eluent: ethyl acetate:methyl chloride—1:2–3) to give the title compound as a pale yellow oil, yield: 52.6%.
EXAMPLE 37
N-Propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was N-propyl-β-hydroxy-4-methylsulfonylphenethylamine instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine. The obtained title compound was pale yellow oil, yield 50.0%.
EXAMPLE 38
N-Cyclopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was N-cyclopropyl-β-hydroxy-4-methylsulfonylphenethylamine instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 39
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was 4-chlorophenacetyl chloride instead of phenacetyl chloride. The obtained title compound was pale yellow oil, yield 60.0%.
EXAMPLE 40
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-3-chlorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was 3-chlorophenacetyl chloride instead of phenacetyl chloride. The obtained title compound was pale yellow oil, yield 50.4%.
EXAMPLE 41
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-bromophenacetamide
The procedure is in the same manner as described in example 37, except that the starting material was 4-bromophenacetyl chloride instead of phenacetyl chloride. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 42
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was 4-fluorophenacetyl chloride instead of phenacetyl chloride. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 43
N-Propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-propyl-β-hydroxy-4-methylsulfonylphenethylamine and 3-methylphenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was a pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 44
N-Propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-propyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-methylphenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was a pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 45
N-Propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-propyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-fluorophenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 46
N-Propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-propyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-chlorophenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was a pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 47
N-Cylcopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials are N-cyclopropyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-methylphenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 48
N-Cyclopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]methyl-3-methylphenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-cyclopropyl-β-hydroxy-4-methylsulfonylphenethylamine and 3-methylphenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was a pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 49
N-Cyclohexyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-cyclopropyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-chlorophenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 50
N-Cylcopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl]ethyl-4-fluorophenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-cyclopropyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-fluorophenacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 51
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was 3-methylphenacetyl chloride instead of phenacetyl chloride. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 52
N-Methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-2,4-dimethylphenacetamide
The procedure was in the same manner as described in example 36, except that the starting material was 2,4-dimethylphenacetyl chloride instead of phenacetyl chloride. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 53
N-Propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl]ethyl-4-phenoxyphenacetamide
The procedure was in the same manner as described in example 36, except that the starting materials were N-propyl-β-hydroxy-4-methylsulfonylphenethylamine and 4-phenoxyacetyl chloride instead of N-methyl-β-hydroxy-4-methylsulfonylphenethylamine and phenacetyl chloride, respectively. The obtained title compound was pale yellow oil and used directly into the oxidation reaction of the next reaction.
EXAMPLE 54
N-Propyl-N-[2-hydroxy-2-(3-bromophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-propyl-β-hydroxy-3-bromophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained, yield 22.8%.
EXAMPLE 55
N-Propyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-propyl-β-hydroxy-3-chlorophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 45.2%.
EXAMPLE 56
N-Cycopropyl-N-[2-hydroxy-2-(4-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-propyl-β-hydroxy-4-chlorophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 28.1%.
EXAMPLE 57
N-Propyl-N-[2-hydroxy-2-(3-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-propyl-β-hydroxy-3-fluorophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 32.3%.
EXAMPLE 58
N-Propyl-N-[2-hydroxy-2-(4-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride-and N-propyl-β-hydroxy-4-fluorophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 29.4%.
EXAMPLE 59
N-Cycopropyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-propyl-β-hydroxy-3-chlorophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 13.8%.
EXAMPLE 60
N-Cycopropyl-N-[2-hydroxy-2-(4-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-cyclopropyl-β-hydroxy-4-fluorophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 28.7%.
EXAMPLE 61
N-Propyl-N-[2-hydroxy-2-(3-bromophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-propyl-β-hydroxy-3-bromophenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 28.7%.
EXAMPLE 62
N-Cycopropyl-N-[2-hydroxy-2-(4-methylphenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 25, except that the starting materials were aminosulfonyl phenacetyl chloride and N-cyclopropyl-β-hydroxy-4-methylphenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 29.6%.
EXAMPLE 63
N-Cycopropyl-N-[2-hydroxy-2-(3-methylphenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure is in the same manner as described in example 25, the starting materials are aminosulfonyl phenacetyl chloride and N-cyclopropyl-β-hydroxy-4-methylphenethylamine instead of 4-methylsulfonyl phenacetyl chloride and N-methyl-β-hydroxyphenethylamine, respectively. The title compound was obtained as light yellow oil, yield 37.6%.
Preparation of N-alkyl-N-[2-oxo-2-substituted phenyl]ethyl-4-methylsulfonyl(or aminosulfonyl)phenacetamides
EXAMPLE 64
N-Methyl-N-(2-oxo-phenyl)ethyl-4-methylsulfonylphenacetamide
To a hot solution of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide (prepared in accordance with Example 25) in 25 ml of acetone was added with stirring 3 ml of Jone's reagent. The mixture was stirred until the starting material disappeared, as monitored by TLC. To the reaction mixture was added 10 ml of isopropanol and the solution turned green in color. This solution was evaporated and the residue was mixed with ethyl acetate/water (50 ml/50 ml). The aqueous phase was extracted with 3×20 ml of ethyl acetate. The combined organic phase was washed with water until it reached a pH 7 and then was dried over sodium sulfate. The solvent was evaporated and the residue was purified by column chromatograph on silica gel (eluent: ethyl acetate:methyle chloride—1:1–2) to give the title compound as a white solid. Mp. 132–133° C., yield: 79.5%.
EXAMPLE 65
N-Propyl-N-[2-oxo-2-(4-methylphenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-methylphenyl)]-ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as a yellow oil, yield 59.0%.
EXAMPLE 66
N-Methyl-N-[2-oxo-2-(4-methylphenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylphenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 49.0%.
EXAMPLE 67
N-Propyl-N-[2-oxo-2-(4-fluorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-fluorophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 50.0%.
EXAMPLE 68
N-Cyclopropyl-N-[2-oxo-2-(4-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-chlorophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 50.0%.
EXAMPLE 69
N-Cyclopropyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 46.9%.
EXAMPLE 70
N-Methyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material is N-methyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 70.6%.
EXAMPLE 71
N-Propyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 46.8%.
EXAMPLE 72
N-Methyl-N-[2-oxo-2-(3-bromophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-methyl-N-[2-hydroxy-2-(3-bromophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 46.8%.
EXAMPLE 73
N-Cyclohexyl-N-(2-oxo-2-phenylethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-cyclohexyl-N-[2-hydroxy-2-phenyl]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as a yellow oil, yield 49.5%.
EXAMPLE 74
N-Cyclopropyl-N-[2-oxo-2-(3-fluorophenyl)]ethyl-4-methylsulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(3-fluorophenyl)]ethyl-4-methylsulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 51.7%.
Preparation of N-alkyl-N-[2-oxo-2-(4-methylsulfonyl or 4-aminosulfonyl)phenyl]ethyl-substituted phenacetamides
EXAMPLE 75
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide
To a hot solution of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide (prepared in accordance with Example 43) in 25 ml of acetone was added with stirring 3 ml of Jone's reagent. The mixture was stirred until the starting material disappeared, as monitored by TLC. To the reaction mixture was added 10 ml of isopropanol and the solution turned green in color. This solution was then evaporated and the residue was mixed with ethyl acetate/water(50 ml/50 ml). The aqueous phase was extracted with 3×20 ml of ethyl acetate. The combined organic phase was washed with water until it reached a pH 7 and then dried over sodium sulfate. The solvent was evaporated and the residue was purified by column chromatograph on silica gel (eluent: ethyl acetate:methyle chloride—1:1–2) to give the title compound as a pale yellow solid. Mp. 97.6–99° C., yield: 41.0%. M + =345
EXAMPLE 76
N-Propyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide
The procedure was in the same manner as described in Example 75, except that the starting material was N-propyll-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as a pale yellow solid, mp. 156–157° C. yield 48.7%.
M + =373, C 20 H 23 NO 4 S
1 H-NMR: δ8.14–7.25 (dd, 4H, ArH, J=8.4), 7.36–7.25 (m, 4H, ArH), 4.74 (s, 2H, CH 2 ), 3.83 (s, 3H, CH3), 3.40–3.34 (t, 2H, CH2, J=7.2), 3.07 (s, 3H, SO 2 CH 3 ), 1.58–1.50 (m, 2H, NCH 2 ), 0.91–0.86 (t, 3H, CH 3 , J=7.2)
EXAMPLE 77
N-Cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide
The procedure was in the same manner as described in Example 75, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow oily liquid, yield: 41.7%. M + =405
EXAMPLE 78
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide
The procedure was in the same manner as described in Example 75, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 163–165° C. yield: 34.0%.
M + =379, C 18 H 20 NClO 4 S
1 H-NMR: δ8.15–8.05 (dd, 4H, ArH, J=8.7), 7.34–7.19 (m, 4H, ArH), 4.84 (s, 2H, CH 2 ), 3.81 (s, 3H, CH3), 3.14 (s, 3H, CH3), 3.08 (s, 3H, SO 2 CH 3 )
EXAMPLE 79
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-3-chlorophenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-3-chlorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as yellow solid, yield: 24.7%.
EXAMPLE 80
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-bromophenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-bromophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 156.7–158.1° C., yield: 56.8%, M + =424
1 H-NMR: δ8.15–8.05 (dd, 4H, ArH, J=8.7), 7.34–7.19 (m, 4H, ArH), 4.84 (s, 2H, CH 2 ), 3.81 (s, 3H, CH3), 3.14 (s, 3H, CH3), 3.08 (s, 3H, SO 2 CH 3 )
EXAMPLE 81
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 109.3–111.4° C., yield: 37.8%, M + =363
1 H-NMR: δ8.14–8.04 (dd, 4H, ArH, J=8.4), 7.29–7.03 (m, 4H, ArH), 4.83 (s, 2H, CH 2 ), 3.81 (s, 2H, CH2), 3.14 (s, 3H, CH3), 3.04 (s, 3H, SO 2 CH 3 ), 2.34 (s, 3H, CH3), 1.57–150 (m, 2H, CH2), 0.92–0.87 (t, 3H, CH3)
EXAMPLE 82
N-Propyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 129.6–131.0° C., yield: 26.6%, M + =387
1 H-NMR: δ8.15–8.02 (dd, 4H, ArH, J=7.8), 7.24–7.06 (m, 4H, ArH), 4.73 (s, 2H, CH 2 ), 3.79 (s, 2H, CH2), 3.40–3.34 (t, 2H, CH2, J=7.8), 3.07 (s, 3H, SO 2 CH 3 ), 2.34 (s, 3H, CH3), 1.57–1.50 (m, 2H, CH2), 0.92–0.87 (t, 3H, CH3)
EXAMPLE 83
N-Propyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 129.6–131.0° C., yield: 36.2%, M + =387
1 H-NMR: δ8.14–8.02 (dd, 4H, ArH, J=7.8), 7.18–7.12 (m, 4H, ArH), 4.72 (s, 2H, CH 2 ), 3.77 (s, 2H, CH2), 3.39–3.33 (t, 2H, CH2, J=7.8), 3.07 (s, 3H, SO 2 CH 3 ), 2.33 (s, 3H, CH3), 1.58–1.51 (m, 2H, CH2), 0.92–0.87 (t, 3H, CH3)
EXAMPLE 84
N-Propyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-fluorolphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 174.5–175.0° C., yield: 40.6%, M + =391
1 H-NMR: δ8.15–8.03 (dd, 4H, ArH, J=8.1), 7.28–7.00 (m, 4H, ArH), 4.74 (s, 2H, CH 2 ), 3.79 (s, 2H, CH2), 3.41–3.35 (t, 2H, CH2, J=7.5), 3.07 (s, 3H, SO 2 CH 3 ), 1.61–1.54 (m, 2H, CH2), 0.94–0.89 (t, 3H, CH3, J=7.5)
EXAMPLE 85
N-Propyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 133.0–134.0° C., yield: 32.1%, M + =407
1 H-NMR: δ8.15–8.02 (dd, 4H, ArH, J=8.7), 7.33–7.21 (dd, 4H, ArH, J=8.1), 4.74 (s, 2H, CH 2 ), 3.79 (s, 2H, CH2), 3.40–3.34 (t, 2H, CH2, J=7.5), 3.07 (s, 3H, SO 2 CH 3 ), 1.62–1.54 (m, 2H, CH2), 0.95–0.90 (t, 3H, CH3, J=7.5)
EXAMPLE 86
N-Cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 109.0–111.0° C., yield: 36.2%, M + =385
1 H-NMR: δ8.12–8.02 (dd, 4H, ArH, J=8.4), 7.20–7.12 (m, 4H, ArH), 4.78 (s, 2H, CH 2 ), 3.97 (s, 2H, CH2), 3.08 (s, 3H, SO2CH3), 2.91–2.84 (m, 1H, CH), 2.33 (s, 3H, CH3), 0.96–0.83 (m, 4H, CH2CH2)
EXAMPLE 87
N-Cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-methylphenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 81.0–83.0° C., yield: 52.8%, M + =385
1 H-NMR: δ8.13–8.02 (dd, 4H, ArH, J=8.4), 7.24–7.01 (m, 4H, ArH), 4.79 (s, 2H, CH 2 ), 3.98 (s, 2H, CH2), 3.07 (s, 3H, SO2CH3), 2.92–2.88 (m, 1H, CH), 2.34 (s, 3H, CH3), 0.97–0.84 (m, 4H, CH2CH2)
EXAMPLE 88
N-Cyclohexyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-cyclohexyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-chlorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 149.1–150.6° C., yield: 15.2%, M + =429
1 H-NMR: δ8.16–8.03 (dd, 4H, ArH, J=8.4), 7.34–7.24 (m, 4H, ArH), 4.59 (s, 2H, CH 2 ), 3.81 (s, 2H, CH2), 3.65–3.61 (m, 1H, CH) 3.07 (s, 3H, SO2CH3), 1.79–1.20, 2.33 (m, 10H, (CH2)5)
EXAMPLE 89
N-Cylcopropyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-cyclopropyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-fluorophenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 108.8–110.0° C., yield: 43.1%, M + =389
1 H-NMR: δ8.12–8.03 (dd, 4H, ArH, J=8.4), 7.29–6.98 (tt, 4H, ArH), 4.79 (s, 2H, CH 2 ), 3.98 (s, 2H, CH2), 3.07 (s, 3H, SO2CH3), 3.00–2.90 (m, 1H, CH), 0.96–0.86 (m, 4H, CH2CH2)
EXAMPLE 90
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-3-methylphenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow solid, Mp. 123.8–124.6° C., yield: 47.0%, M + =359
1 H-NMR: δ8.15–8.04 (dd, 4H, ArH, J=8.4), 7.23–7.07 (m, 4H, ArH), 4.83 (s, 2H, CH 2 ), 3.80 (s, 2H, CH2), 3.13 (s, 3H, CH3), 3.08 (s, 3, SO 2 CH 3 ), 2.35 (s, 3H, CH3)
EXAMPLE 91
N-Methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-2,4-dimethylphenacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-2,4-dimethylphenacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide. The title compound was obtained as a yellow oily liquid, yield: 46.3%,
EXAMPLE 92
N-Propyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-phenoxyacetamide
The procedure was in the same manner as described in example 75, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-4-phenoxyacetamide instead of N-methyl-N-[2-hydroxy-2-(4-methylsulfonylphenyl)]ethyl-phenacetamide, The title compound was obtained as a yellow solid, Mp. 96.0–98.0° C., yield: 94.7%, M + =389
1 H-NMR: δ8.13–8.00 (dd, 4H, ArH, J=8.1), 7.32–6.93 (m, 5H, ArH), 4.82 (s, 2H, CH 2 ), 4.76 (s, 2H, CH2), 3.45–3.40 (t, 2H, CH2, J=7.5), 3.08 (s, 3H, SO 2 CH 3 ), 1.69–1.62 (m, 2H, CH2), 0.98–0.93 (t, 3H, CH3, J=7.5)
EXAMPLE 93
N-Propyl-N-[2-oxo-2-(3-bromophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(3-bromophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide.
The title compound was obtained as yellow oil, yield 52.0%.
EXAMPLE 94
N-Propyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material is N-propyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 28.1%.
EXAMPLE 95
N-Cycopropyl-N-[2-oxo-2-(4-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material is N-propyl-N-[2-hydroxy-2-(4-chlorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 48.7%.
EXAMPLE 96
N-Propyl-N-[2-oxo-2-(3-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(3-fluorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 38.7%.
EXAMPLE 97
N-Propyl-N-[2-oxo-2-(4-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-chlorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 37.8%.
EXAMPLE 98
N-Cycopropyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(3-chlorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 19.1%.
EXAMPLE 99
N-Cycopropyl-N-[2-oxo-2-(4-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-fluorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 35.9%.
EXAMPLE 100
N-Propyl-N-[2-oxo-2-(3-bromophenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(3-bromophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 52.0%.
EXAMPLE 101
N-Cycopropyl-N-[2-oxo-2-(4-methylphenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-methylphenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 39.7%.
EXAMPLE 102
N-Cycopropyl-N-[2-oxo-2-(3-methylphenyl)]ethyl-4-aminosulfonylphenacetamide
The procedure was in the same manner as described in example 64, except that the starting material was N-propyl-N-[2-hydroxy-2-(4-chlorophenyl)]ethyl-4-aminosulfonyl phenacetamide instead of N-methyl-N-(2-hydroxy-2-phenyl) ethyl-4-methylsulfonyl phenacetamide. The title compound was obtained as yellow oil, yield 42.6%.
Preparation of N-alkyl-3,4-diaryl-2,5-dihydropyrrole-2-ones
EXAMPLE 103
N-Methyl-3-(4-methylsulfonylphenyl)-4-phenyl-2,5-dihydropyrrole-2-one
A potassium t-butanolate was prepared by refluxing 0.200 g of potassium in 25 ml of anhydrous t-butanol in a nitrogen atmosphere for 2–4 hours. To the potassium t-butanolate solution was rapidly added a solution of 1 mmol of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide described in Example 50 in 40 ml of hot t-butanol. The mixture turned to yellow-green in color, and was stirred until the starting material disappeared, as monitored by TLC. The reaction mixture was poured into ice-water and neutralized by adding dilute hydrochloric acid. The mixture was extracted by ethyl acetate. The combined organic phase was washed with water and dried over sodium sulfate. The solvent was evaporated and the residue was purified by column chromatograph on silica gel (eluent: ethyl acetate:petroleum ether 1:2–1) to give the title compound as white solid. Mp. 195° C. (dec), yield: 63.9%.
M + =327. C 19 H 17 ClNO 3 S
1 H-NMR: δ8.0–7.7 (dd, 4H, ArH, J=8.4), 7.4–7.2 (m, 2H, ArH), 7.0 (t, 2H, ArH, J=6.6), 4.3 (s, 2H, CH 2 ), 3.1 (s, 3H, SO 2 CH 3 ), 3.1 (s, 3H, NCH 3 )
EXAMPLE 104
N-Propyl-3-(4-methylsulfonylphenyl)-4-(4-methylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(4-methylphenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 155.5–157.6° C., yield: 57.2%.
M + =369 C 21 H 23 NO 3 S
1 H-NMR: δ7.9–7.63 (dd, 4H, ArH, J=7.8), 7.13 (s, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.55 (t, 2H, NCH 2 , J=7.53), 3.05 (s, 3H, SOCH 3 ), 2.36 (s, 3H, Ar—CH 3 ), 1.75–1.68 (m, 2H, NCCH 2 ) 1.0 (t, CH 3 , J=7.5)
EXAMPLE 105
N-Methyl-3-(4-methylsulfonylphenyl)-4-(4-methylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylphenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide The title compound was obtained as a white solid, Mp. 182.9–185.1° C., yield: 69.2%.
M + =341 C 19 H 19 NO 3 S
1 H-NMR: δ7.92–7.61 (dd, 4H, ArH, J=7.8), 7.12 (s, 4H, ArH), 4.33 (s, 2H, CH 2 ), 3.18 (s, 3H, NCH 3 ), 3.06 (s, 3H, SOCH 3 ), 2.36 (s, 3H, Ar—CH 3 )
EXAMPLE 106
N-Propyl-3-(4-methylsulfonylphenyl)-4-(4-fluorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(4-fluorophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 150–52° C., yield: 20.9%.
M + =373.0847, C 20 H 20 FNO 3 S
1 H-NMR: δ7.93–7.61 (dd, 4H, ArH, J=8.4), 7.24–7.00 (m, 4H, ArH), 4.33 (s, 2H, CH 2 ), 3.58–3.54 (t, NCH 2 , J=7.2), 3.06 (s, 3H, SO 2 CH 3 ), 1.75–1.68 (m, 2H, NCCH 2 ), 1.02–0.97 (t, 3H, CH 3 )
EXAMPLE 107
N-Cyclopropyl-3-(4-methylsulfonylphenyl)-4-(4-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(4-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 107–109° C. (dec), yield: 59.2%.
M + =389.387, C 20 H 18 ClNO 3 S
1 H-NMR: δ7.92–7.58 (dd, 4H, ArH, J=8.4), 7.34–7.03 (m, 4H, ArH), 4.27 (s, 2H, CH 2 ), 3.05 (s, 3H, SO 2 CH 3 ), 2.88 (m, 1H, NCH), 0.94–0.87 (m, 4H, CH 2 CH 2 )
EXAMPLE 108
N-Cyclopropyl-3-(4-methylsulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 158.4–160.1° C. (dec), yield: 53.3%.
M + =389.387, C 20 H 18 ClNO 3 S
1 H-NMR: δ7.92–7.58 (dd, 4H, ArH, J=8.4), 7.31–7.14 (dd, 4H, ArH, J=6.3), 4.27 (s, 2H, CH 2 ), 3.05 (s, 3H, SO 2 CH 3 ), 2.88 (m, 1H, CH), 0.94–0.87 (m, 4H, (CH2)2
EXAMPLE 109
N-Methyl-3-(4-methylsulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 170–172.4° C., yield: 47.2%.
M + =361.0539, C 18 H 16 ClNO 3 S
1 H-NMR: δ8.04–7.59 (dd, 4H, ArH, J=7.8), 7.35–7.04 (m, 4H, ArH), 4.33 (s, 2H, CH 2 ), 3.19 (s, 3H, NCH 3 ), 3.06 (s, 3H, SO 2 CH 3 )
EXAMPLE 110
N-Propyl-3-(4-methylsulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Propyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 147.6–149.4° C., yield: 52.6%.
M + =389, C 20 H 20 ClNO 3 S, Elemental analysis Fnd(Cld): C, 61.76 (61.61), H, 5.22 (5.17), N, 3.95 (3.59).
1 H-NMR: δ7.99–7.61 (dd, 4H, ArH, J=8.1), 7.35–7.06 (m, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.56 (t, NCH 2 , J=7.5), 3.05 (s, 3H, SO 2 CH 3 ), 1.66 (m, 2H, NCCH 2 ), 1.0–0.97 (t, 3H, CH 3 , J=7.5)
EXAMPLE 111
N-Methyl-3-(4-methylsulfonylphenyl)-4-(3-bromophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4.bromophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 137.9–139° C., yield: 71.9%.
M + =407.405, C 18 H 16 BrNO 3 S
Elemental analysis Fnd(Cld): C, 53.48 (53.21), H, 4.15 (3.97), N, 3.48 (3.45).
1 H-NMR: δ7.9–7.6 (dd, 4H, ArH, J=8.1), 7.5–7.1 (m, 4H, ArH), 4.3 (s, 2H, CH 2 ), 3.2 (s, 3H, NCH 3 ), 3.1 (s, 3H, SO 2 CH 3 ); MS: 407, 405
EXAMPLE 112
N-Cyclohexyl-3-(4-methylsulfonylphenyl)-4-phenyl-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclohexyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 183–185° C., yield: 26.4%.
M + =395.313, C 23 H 25 NO 3 S
1 H-NMR: δ7.9–7.6 (dd, 4H, ArH, J=8.1), 7.35–7.22 (m, 5H, ArH), 4.31 (s, 2H, CH 2 ), 4.16 (m, 1H, NCH), 3.05 (s, 3H, SO 2 CH 3 ), 1.91–1.19 (m, 10H, (CH2)5)
EXAMPLE 113
N-Cyclopropyl-3-(4-methylsulfonylphenyl)-4-(3-fluorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(3-fluorophenyl)]ethyl-4-methylsulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 179–180° C., yield: 47.4%.
M + =371, C 20 H 18 FNO 3 S
Elemental analysis Fnd(Cld): C, 64.57 (64.68), H, 4.86 (4.88), N, 4.01 (3.77).
1 H-NMR: δ7.92–7.5 8 (dd, 4H, ArH, J=8.1), 7.31–6.92 (m, 4H, ArH), 4.27 (s, 2H, CH 2 ), 3.06 (s, 3H, SO 2 CH 3 ), 2.91–2.88 (m, 1H, CH), 0.94–0.89 (m, 4H, (CH2)2)
EXAMPLE 114
N-Methyl-3-phenyl-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphenyl)]ethyl-4-phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 163.4–165.3° C., yield: 48.2%.
M + =327.298, C 18 H 17 NO 3 S
1 H-NMR: δ7.87–7.44 (dd, 4H, ArH, J=8.1), 7.36 (s, 5H, ArH), 4.33 (s, 2H, CH 2 ), 3.2 (s, 3H, NCH 3 ), 3.06 (s, 3H, SO 2 CH 3 )
EXAMPLE 115
N-Propyl-3-phenyl-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 127.4–12229.0° C., yield: 73.3%.
M + =355.326, C 20 H 21 NO 3 S
1 H-NMR: δ7.8–7.4 (dd, 4H, ArH, J=7.8), 7.34 (s, 5H, ArH), 4.30 (s, 2H, CH 2 ), 3.47–3.52 (t, 2H, CH2, J=7.2), 3.04 (s, 3H, SO 2 CH 3 ), 1.74–1.66 (m, 2H, CH2), 1.00–0.95 (t, 3H, CH 3 , J=7.2)
EXAMPLE 116
N-Cyclopropyl-3-phenyl-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide The title compound was obtained as a white solid, Mp. 144–146° C., yield: 77.2%.
M + =353.1094, C 20 H 19 NO 3 S
1 H-NMR: δ7.86–7.44 (dd, 4H, ArH, J=8.4), 7.35 (s, 5H, ArH), 4.27 (s, 2H, CH 2 ), 3.06 (s, 3H, SO 2 CH 3 ), 2.91–2.89 (m, 1H, NCH), 0.94–0.88 (dd, 4H, CH 2 CH 2 )
EXAMPLE 117
N-Methyl-3-(4-chlorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-chlorophenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 129–131° C., yield: 76.7%.
M + =3610542, C 18 H 16 NClO 3 S
1 H-NMR: δ7.90–7.44 (dd, 4H, ArH, J=8.7), 7.34–7.16 (m, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.20 (s, 3H, NCH 3 ), 3.08 (s, 3H, SO 2 CH 3 )
EXAMPLE 118
N-Methyl-3-(3-chlorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 102, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-chlorophenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 168–169.6° C., yield: 58.8%.
M + =361.057, C 18 H 16 NClO 3 S
1 H-NMR: δ7.90–7.4 (dd, 4H, ArH, J=8.4), 7.4–7.2 (m, 4H, ArH), 4.34 (s, 2H, CH 2 ), 3.2 (s, 3H, NCH 3 ), 3.08 (s, 3H, SO 2 CH 3 )
EXAMPLE 119
N-Methyl-3-(4-bromophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-bromophenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 161–163° C., yield: 71.2%.
M + =404.9939, C 18 H 16 NBrO 3 S
1 H-NMR: δ7.90–7.48 (dd, 4H, ArH, J=8.1), 7.46–7.25 (dd, 4H, ArH, J=8.4), 4.32 (s, 2H, CH 2 ), 3.2 (s, 3H, NCH 3 ), 3.08 (s, 3H, SO 2 CH 3 )
EXAMPLE 120
N-Methyl-3-(4-fluorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-fluorophenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 110.9–111.4° C., yield: 80.4%.
M + =345.0836, C 18 H 16 NFO 3 S
1 H-NMR: δ7.90–7.44 (dd, 4H, ArH, J=8.6), 7.39–7.35 (q, 2H, ArH), 7.08–7.03 (t, 2H, ArH), 4.32 (s, 2H, CH 2 ), 3.2 (s, 3H, NCH 3 ), 3.07 (s, 3H, SO 2 CH 3 )
EXAMPLE 121
N-Propyl-3-(3-methylphenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(3-methylsulfonylphyl)]ethyl-3-methylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 120–122° C., yield: 45.5%.
M + =369.340, C 19 H 19 NO 3 S
1 H-NMR: δ7.86–7.46 (dd, 4H, ArH, J=7.8), 7.25–7.07 (m, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.59–3.54 (t, 2H, CH2), 3.06 (s, 3H, SO 2 CH 3 ), 2.33 (s, 3H, CH3), 1.75–1.65 (m, 2H, CH2), 1.02–0.97 (t, 3H, CH3, J=7.2)
EXAMPLE 122
N-Propyl-3-(4-methylphenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-methylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 161–163° C., yield: 70.4%.
M + =369.340, C 19 H 19 NO 3 S
1 H-NMR: δ7.87–7.47 (dd, 4H, ArH, J=8.1), 7.29–7.15 (dd, 4H, ArH, J=7.8), 4.30 (s, 2H, CH 2 ), 3.59–3.54 (t, 2H, CH2, J=7.2), 3.06 (s, 3H, SO 2 CH 3 ), 2.36 (s, 3H, CH3), 1.75–1.68 (m, 2H, CH2), 1.02–0.97 (t, 3H, CH3, J=7.5)
EXAMPLE 123
N-Propyl-3-(4-fluorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-fluorophenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 120–121° C., yield: 57.7%.
M + =387.373, C 18 H 16 NFO 3 S
1 H-NMR: δ7.86–7.43 (dd, 4H, ArH, J=8.4), 7.39–6.99 (m, 4H, ArH), 4.30 (s, 2H, CH 2 ), 3.56–3.51 (t, 2H, CH2, J=7.2), 3.05 (s, 3H, SO 2 CH 3 ), 1.76–1.63 (m, 2H, CH2), 1.00–0.95 (t, 3H, CH3, J=7.8)
EXAMPLE 124
N-Propyl-3-(4-chlorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-chlorophenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 146–148° C., yield: 83.3%.
M + =391.389, C 18 H 16 NClO 3 S
Elemental analysis Fnd(Cld): C, 61.52 (61.61), H, 5.16 (5.17), N, 3.89 (3.59).
1 H-NMR: δ7.84–7.42 (dd, 4H, ArH, J=8.4), 7.32–7.24 (broad, 4H, ArH), 4.29 (s, 2H, CH 2 ), 3.54–3.50 (t, 2H, CH2, J=7.2), 3.01 (s, 3H, SO 2 CH 3 ), 1.73–1.64 (m, 2H, CH2), 0.97–0.93 (t, 3H, CH3, J=7.2)
EXAMPLE 125
N-Cyclopropyl-3-(4-methylphenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-(4-methyl)phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 214–216° C., yield: 48.3%.
M + =367.338, C 21 H 21 NO 3 S
1 H-NMR: δ7.86–7.45 (dd, 4H, ArH, J=8.4), 7.26–7.14 (dd, 4H, ArH, J=8.4), 4.24 (s, 2H, CH 2 ), 3.06 (s, 3H, SO 2 CH 3 ), 2.90–2.80 (m, 1H, NCH), 2.36 (s, 3H, CH3), 0.92–0.8 (m, 4H, CH 2 CH 2 )
EXAMPLE 126
N-Cyclopropyl-3-(3-methylphenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-3-(3-methyl)phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 136.5–137.4° C., yield: 49.0%.
M + =367, C 21 H 21 NO 3 S
1 H-NMR: δ7.85–7.44 (dd, 4H, ArH, J=7.8), 7.24–7.05 (m, 4H, ArH), 4.25 (s, 2H, CH 2 ), 3.05 (s, 3H, SO 2 CH 3 ), 2.90 (m, 1H, NCH), 2.32 (s, 3H, CH3), 0.89 (m, 4H, CH 2 CH 2 )
EXAMPLE 127
N-Cyclohexyl-3-(4-chlorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclohexyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-(4-chloro)phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 142–143.5° C., yield: 53.7%.
M + =429.347, C 23 H 24 NClO 3 S
Elemental analysis Fnd(Cld): C, 64.41 (64.25), H, 5.57 (5.63), N, 3.50 (3.26).
1 H-NMR: δ7.89–7.44 (dd, 4H, ArH, J=8.4), 7.33 (s, 4H, ArH), 4.28 (s, 2H, CH 2 ), 4.16–4.10 (m, 1H, CH), 3.07 (s, 3H, SO 2 CH 3 ), 1.91–1.18 (m, 10H, (CH2)5)
EXAMPLE 128
N-Cyclopropyl-3-(4-fluorophenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-cyclopropyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-3-(4-fluorol)phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 170.0–172.0° C., yield: 20.0%.
M + =371.183, C 20 H 18 NFO 3 S
1 H-NMR: δ7.88–7.43 (dd, 4H, ArH, J=8.4), 7.38–7.01 (m, 4H, ArH), 4.25 (s, 2H, CH 2 ), 3.06 (s, 3H, SO 2 CH 3 ), 2.89 (m, 1H, NCH), 0.93–0.87 (m, 4H, CH 2 CH 2 )
EXAMPLE 129
N-Methyl-3-(3-methylphenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-(3-methyl)phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 163.0–165.0° C., yield: 81.1%.
M + =341.312 C 19 H 19 NO 3 S
1 H-NMR: δ7.86–7.44 (dd, 4H, ArH, J=7.8), 7.24–7.06 (m, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.19 (s, 3H, NCH 3 ), 3.05 (s, 3H, SO 2 CH 3 ), 2.33 (s, 3H, CH3)
EXAMPLE 130
N-Methyl-3-(2,4-dimethylphenyl)-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-methyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-4-(2,4-dimethyl)phenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 59.0–61° C., yield: 33.4%.
M + =355 C 20 H 21 NO 3 S
1 H-NMR: δ7.81–7.34 (dd, 4H, ArH, J=8.7), 7.07–6.96 (m, 3H, ArH), 4.40 (s, 2H, CH 2 ), 3.18 (s, 3H, NCH 3 ), 3.01 (s, 3H, SO 2 CH 3 ), 2.34 (s, 3H, CH3), 2.07 (s, 3H, CH3)
EXAMPLE 131
N-Propyl-3-phenoxy-4-(4-methylsulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(4-methylsulfonylphyl)]ethyl-phenoxyacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 163–165° C., yield: 73.1%.
M + =371, C 20 H 21 NO 4 S
1 H-NMR: δ7.96–7.85 (dd, 4H, ArH, J=8.4), 7.34–7.03 (m, 5H, ArH), 4.35 (s, 2H, CH 2 ), 3.53–3.48 (t, 2H, CH2, J=7.2), 3.05 (s, 3H, SO 2 CH 3 ), 1.74–1.66 (m, 2H, CH2), 1.00–0.94 (t, 3H, CH3, J=7.2)
EXAMPLE 132
N-Propyl-3-(4-aminosulfonylphenyl)-4-(3-bromophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-propyl-N-[2-oxo-2-(3-bromophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 162.5–163.0° C., yield: 77.0%.
M + =435.437 C 19 H 19 N 2 O 3 SBrS
1 H-NMR: δ7.90–7.57 (dd, 4H, ArH, J=8.1), 7.50–7.11 (m, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.58–3.53 (t, 2H, NCH 2 , J=7.5), 1.78–1.61 (m, 2H, NCCH 2 ), 1.02–0.97 (t, 3H, NCCCH 3 , J=7.5)
EXAMPLE 133
N-Propyl-3-(4-aminosulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Propyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 149–150° C., yield: 43.0%.
M + =390.361, C 18 H 19 ClNO 3 S
Elemental analysis Fnd(Cld): C, 58.36 (58.40), H, 5.26 (4.90), N, 6.95 (7.17).
1 H-NMR: δ7.9–7.44 (dd, 4H, ArH, J=8.7), 7.3–7.1 (m, 4H, ArH), 4.90 (s, 2H, NH 3 ), 4.3 (s, 2H, CH 2 ), 3.6 (t, NCH 2 , J=7.8), 1.8–1.7 (m, 2H, NCCH 2 ), 1.0 (t, 3H, CH 3 , J=7.8)
EXAMPLE 134
N-Cylcopropyl-3-(4-aminosulfonylphenyl)-4-(4-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Cycopropyl-N-[2-oxo-2-(4-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 198.4–200° C., yield: 16.1%.
M + =391.362, C 19 H 17 ClNO 3 S
1 H-NMR: δ8.11–7.96 (dd, 4H, ArH, J=8.1), 7.79–7.60 (dd, 4H, ArH, J=7.8), 5.08 (s, 2H, NH 3 ), 3.02 (m, 1H, CH), 0.54 (m, 2H, CH 2 CH 2 )
EXAMPLE 135
N-Propyl-3-(4-aminosulfonylphenyl)-4-(3-fluorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Propyl-N-[2-oxo-2-(3-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 188.5–190.4° C., yield: 44.4%.
M + =374.345 C 18 H 19 FNO 3 S
1 H-NMR: δ7.91–7.56 (dd, 4H, ArH, J=8.1), 7.33–6.95 (m, 4H, ArH), 4.32 (s, 2H, CH 2 ), 3.59–3.54 (t, NCH 2 , J=7.5), 1.78–1.68 (m, 2H, NCCH 2 ), 1.03–0.98 (t, 3H, CH 3 , J=7.2)
EXAMPLE 136
N-Propyl-3-(4-aminosulfonylphenyl)-4-(4-fluorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Propyl-N-[2-oxo-2-(4-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 179.5–181° C., yield: 77.3%.
M + =374.345 C 18 H 19 FNO 3 S
Elemental analysis Fnd(Cld): C, 61.08 (60.95), H, 5.13 (5.11), N, 7.29 (7.48).
1 H-NMR: δ7.86–7.53 (dd, 4H, ArH, J=8.7), 7.46–7.11 (m, 4H, ArH), 4.48 (s, 2H, CH 2 ), 3.53–3.48 (t, NCH 2 , J=7.2), 1.71–1.68 (m, 2H, NCH 2 ), 0.96–0.92 (t, 3H, CH 3 , J=7.2)
EXAMPLE 137
N-Cylcopropyl-3-(4-aminosulfonylphenyl)-4-(3-chlorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Cycopropyl-N-[2-oxo-2-(3-chlorophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 211–213° C., yield: 62.0%.
M + =402, C 19 H 17 ClNO 3 S
1 H-NMR: δ7.80–7.44 (dd, 4H, ArH, J=7.8), 7.41–7.15 (m, 4H, ArH), 4.45 (s, 2H, NH 3 ), 2.90–2.88 (m, 1H, CH), 0.86–0.76 (m, 4H, CH 2 CH 2 )
EXAMPLE 138
N-Cylcopropyl-3-(4-aminosulfonylphenyl)-4-(4-fluorophenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Cycopropyl-N-[2-oxo-2-(4-fluorophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 222.8–224.1° C., yield: 41.6%.
M + =372, C 19 H 17 FNO 3 S
1 H-NMR: δ7.86–7.50 (dd, 4H, ArH, J=8.4), 7.43–7.10 (m, 4H, ArH), 4.40 (s, 2H, NH 3 ), 2.92–2.87 (m, 1H, CH), 0.91–0.77 (m, 4H, CH 2 CH 2 )
EXAMPLE 139
N-Cylcopropyl-3-(4-aminosulfonylphenyl)-4-(3-bromophenyl-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Cycopropyl-N-[2-oxo-2-(3-bromophenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 219–220.4° C., yield: 62.5%.
M + =434, C 19 H 17 BrNO 3 S
Elemental analysis Fnd(Cld): C, 52.43 (52.67), H, 3.70 (3.95), N, 6.33 (6.46).
1 H-NMR: δ7.86–7.52 (dd, 4H, ArH, J=8.4), 7.58–7.27 (m, 4H, ArH), 4.41 (s, 2H, CH2), 2.94–2.88 (m, 1H, CH), 0.91–0.78 (m, 4H, CH 2 CH 2 )
EXAMPLE 140
N-Cylcopropyl-3-(4-methylphenyl)-4-(4-aminosulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Cycopropyl-N-[2-oxo-2-(4-methylphenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 180.0–182.7° C., yield: 74.7%.
M + =368, C 20 H 20 NO 3 S
1 H-NMR: δ8.19–7.95 (dd, 4H, ArH, J=8.4), 7.46–7.22 (dd, 4H, ArH, J=7.8), 4.98 (s, 2H, CH2), 2.97 (m, 1H, CH), 2.29 (s, 3H, CH3), 0.50–0.45 (m, 4H, CH 2 CH 2 )
EXAMPLE 141
N-Cylcopropyl-3-(3-methylphenyl)-4-(4-aminosulfonylphenyl)-2,5-dihydropyrrole-2-one
The procedure was in the same manner as described in example 103, except that the starting material was N-Cycopropyl-N-[2-oxo-2-(3-methylphenyl)]ethyl-4-aminosulfonylphenacetamide instead of N-methyl-N-(2-oxo-2-phenyl)ethyl-4-methylsulfonylphenacetamide. The title compound was obtained as a white solid, Mp. 206.0–208.0° C., yield: 37.6%.
M + =368, C 20 H 20 NO 3 S
1 H-NMR: δ7.82–7.48 (dd, 4H, ArH, J=8.7), 7.34–7.06 (m, 4H, ArH), 4.40 (s, 2H, CH2), 2.84 (m, 1H, CH), 2.28 (s, 3H, CH3), 0.97–0.77 (m, 4H, CH 2 CH 2 )
PHARMACOLOGICAL EXPERIMENT
1. In vitro Test of Inhibitory Activity for Cyclooxygenase-2 and Cyclooxygenase-1
Cell culture: Adherent macrophages were harvested from the peritoneal cells of male mice (C57BL-6J, Level 2, from Experiment Animal Center, Academy of Military Medical Science) 3 d after the injection (ip) of brewer thioglycollate medium (5 mL/100 g body weight). Shortly, peritoneal cells obtained from 3˜4 mice were mixed and seeded in 48 well cell culture cluster (Costar) at a cell density of 1×10 9 cell/L in RPMI-1640 supplemented with 5% (v/v) newborn calf serum, 100 ku/L penicillin and 100 g/L streptomycin. After settlement for 2˜3 h, non-adherent cells were washed by D-Hanks' balanced salt solution. Then macrophages were cultured in RPMI-1640 without serum. Almost all of adherent cells were macrophages as assessed by Giemsa staining. Cell viability was examined by trypan blue dye exclusion. All incubation procedures were performed with 5% CO 2 in humidified air at 37° C.
COX-2 assay: Macrophages were incubated with test compound at different concentrations or solvent (Me 2 SO) for 1 h and were stimulated with LPS 1 mg/L for 9 h. The amount of PGE 2 in supernatants was measured by RIA. The inhibitory ratio was calculated using the same formula as in COX-1 assay section. Cs, Ct, Cc refer to PGE 2 concentration in supernatants of LPS, test compound, and control groups, respectively.
COX-1: assay Macrophages were incubated with test compound at different concentrations or solvent (Me 2 SO) for 1 h and were stimulated with calcimycin 1 μmol·L −1 for 1 h. The amount of 6-keto-PGF 1□ (a stable metabolite of PGI 2 ) in supernatants was measured by RIA according to manufacturer's guide. The inhibitory ratio was calculated as
IR = ( Cs - Ct ) ( Cs - Cc )
Cs, Ct, Cc refer to 6-keto-PGF 1□ concentration in supernatants of calcimycin, test compound, and control groups, respectively.
Statistical analysis: Data were expressed as the mean±SD of more than three independent experiments. Dose-inhibitory effect curves were fit through “uphill dose response curves, variable slope” using Prism, GraphPad version3.00:
Y
=
1
1
+
10
[
(
log
IC
50
-
X
)
×
Hillslope
}
The inhibitory activities of the compounds of present invention for COX-2 and COX-1 in cell culture are listed in Table 1 below.
TABLE 1 Data of the inhibitory activity of the compounds for COX-2 and COX-1 Example No IC 50 COX-2 (M) IC 50 COX-1 (M) COX-1/COX-2 104 n.d. n.d. 105 7.82E−7 >1.0E−5 106 6.11E−7 >1.0E−5 107 4.21E−7 >1.0E−5 108 7.83E−7 >1.0E−5 109 4.21E−7 >1.0E−5 110 7.83E−7 >1.OE−5 111 6.19E−7 >1.0E−S 112 1.79E−6 >1.0E−5 113 9.98E−7 >1.0E−5 114 1.42E−8 1.12E−6 78.9 115 1.95E−8 1.49E−7 7.6 116 2.53E−8 4.68E−7 18.5 117 2.42E−8 1.59E−7 6.6 118 1.03E−8 >1.0E−5 119 1.18E−8 5.72E−8 4.9 120 1.38E−8 2.00E−7 14.5 121 1.93E−8 1.19E−7 6.2 122 1.50E−8 9.13E−8 6.1 123 2.86E−8 5.02E−7 17.6 124 2.45E−8 8.02E−9 125 9.48E−8 2.36E−7 2.5 126 1.55E−8 2.21E−7 14.3 127 2.07E−8 1.43E−7 128 6.64E−8 >1.0E−5 129 n.d. n.d. 130 n.d. n.d. 131 n.d. n.d. 132 9.98E−7 >1.0E−5 133 4.82E−7 5.44E8 134 n.d. n.d. 135 5.64E−7 >1.0E−5 136 n.d. n.d. 137 1.69E−6 >1.0E−5 138 n.d. n.d. 139 n.d. n.d. 140 n.d. n.d. 141 1.87E−8 >1.0E−5 Rofecoxib 9.57E−9 >1.0E−5
2. In vitro Test of Inhibitory Activity for Cyclooxygenase-1
Rat Carrageenan-induced Foot Pad Edema Assay
Male Sprgue-Dawley rats (190–220 g) were fasted with free access to water at least 16 h prior to experiments. The rats were dosed orally with a 1 ml suspension of test compound in vehicle (0.5% methyl cellulose and 0.025% Tween-20) or with vehicle alone. One hour later a subplantar injection of 0.1 ml of 1% solution of caarageenan in 0.9% strile saline was administered to the right hind foot pad. Paw volume was measured with a displacement plethysmometer 2, 3, and 4 h after caarageenan injection. The results are listed in Table 2 below.
TABLE 2
Data of inhibitory activity of the compounds for rat carrageenan-
induced foot pad edema
Com-
pound
Paw volumes and the inhibitory
Example
Dose
Animal
percentage of edema ( ) hr
No
Mg/kg
No
2
3
4
control
vehicle
8
45.5 ± 12.9
45.5 ± 12.9
45.5 ± 12.9
104
10
8
44.1 ± 6.4
46.2 ± 13.7
48.6 ± 16.5
(24.5%)
(19.3%)
105
10
8
31.0 ± 17.9
37.2 ± 9.6
31.2 ± 10.7
(39.2%)
(48.2%)
108
10
8
38.8 ± 9.8
38.9 ± 11.9
34.0 ± 12.4
(36.4%)
(43.5%)
110
10
8
40.8 ± 8.8
45.4 ± 19.4
38.1 ± 12.4
(25.8%)
(36.7%)
115
10
8
46.4 ± 7.0
47.2 ± 13.3
43.8 ± 14.5
(22.8%)
(27.2%)
117
10
8
22.9 ± 5.9
31.7 ± 13.9
24.5 ± 7.9
(48.2%)
(59.3%)
119
10
8
33.8 ± 17.1
31.8 ± 10.8
30.2 ± 10.9
(48.0%)
(49.8%)
120
10
8
28.9 ± 9.6
37.2 ± 20.0
44.4 ± 21.5
(39.2%)
(26.2%)
122
10
8
33.2 ± 14.2
26.2 ± 9.8
24.5 ± 14.8
(57.2%)
(59.3%)
123
10
8
29.5 ± 14.8
30.9 ± 9.9
29.9 ± 9.4
(49.6%)
(50.3%)
124
10
8
32.5 ± 11.4
37.1 ± 12.7
40.5 ± 5.4
(39.4%)
(32.7%)
125
10
8
35.5 ± 20.0
40.3 ± 18.5
41.5 ± 12.5
(34.1%)
(31.1%)
Rofecoxib
10
8
42.7 ± 16.9
33.1 ± 5.2
30.0 ± 1.8
(45.9%)
(50.2%)
|
The invention relates to sulfonyl-containing 3,4-diaryl-3-pyrrolin-2-ones compounds having formula (I)
wherein R 1 is selected from the group consisting of 4-methylsulfonyl, 4-aminosulfonyl, hydrogen, 2-, 3-, or 4-halogen, C 1 –C 6 -alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl;
R 2 is selected from the group consisting of 4-methylsulfonyl, 4-aminosulfonyl, hydrogen, 2-, 3-, or 4-halogen, C1–C6-alkyl, cyclopentyl, cyclohexyl, C 1 –C 4 -alkoxy, hydroxy, cyano, nitro, amino or trifluoromethyl; and R 3 is selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, i-propyl, c-propyl, n-butyl, isobutyl; provided that when R 1 is a methylsulfonyl or aminosulfonyl group, R 2 is any group as defined above except a methylsulfonyl or aminosulfonyl group; and when R 2 is a methylsulfonyl or aminosulfonyl group, R 1 is any group as defined above except a methylsulfonyl or aminosulfonyl group,
also to processes for the preparation of such compounds, to pharmaceutical compositions containing such compounds, and to the medical use of such compounds in the treatment of diseases relating to the inhibition of cyclooxygenase-2 (COX-2).
| 2
|
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an device for ironing garments, namely the legs of trousers, pants, shorts and the like, and to iron methods using the present invention. Additionally, the present invention relates to advertising and promotional items.
[0002] Traditionally, there have been large, small and miniature ironing boards. Items, such as khaki pants worn in the military, are generally ironed on these types of boards by placing said khaki pants either on the top of the ironing board or inserting the smaller end of the ironing board into the waist of the khaki pants. When it is desired to efficiently and effectively create a crisp crease in said khaki pants, novice users of traditional ironing boards are frustrated in their attempts. It is only after considerable trial and error that an experienced user of traditional ironing boards perfects his/her technique for creating crisp creases quickly and with minimal effort
[0003] Since the result of this traditional method is frustration and unacceptable creases, the need exists for a device that can be used to quickly and accurately iron pants while creating acceptable creases. Additionally the need exists for a versatile device that can accelerate the ironing of pants with the option of having no creases. Also, the need exists for a device that can be used for advertising and promotional purposes.
[0004] Previous attempts to provide for creating creases in articles of clothing such as pants include the following. U.S. Pat. No. 5,971,235, issued to Chanek, teaches a garment creaser which may be used both to apply new creases to an item of clothing and to freshen preexisting creases. It consists of a wide blade fabricated from metal or a similarly rigid and heat-resistant material with a very slender thickness, and a plurality of semi-circular clips which fit closely over the edges of the blade. An item of clothing is creased therewith by folding it over one of the longitudinal edges of the blade, clipping it in place, and ironing over the edge of the blade. One of the longitudinal edges is equipped with a measuring scale which enables precise measurement of the length of the creases, as well as of their placement relative to other features on the item of clothing. Pat. No. 562,276, issued to Boyd, teaches a trousers-creaser made of a board or plate that passes in between the legs of the trousers and a board or plate at each outer side of the trousers and sprint-clamps for pressing the boards or plates toward the center board or plate, thereby smoothing the trousers and forming or maintaining the creases at the front and back of such trousers. The commercially available Corby® Pants Presser devices are examples of high-end mechanical solutions to the pressing of pants.
[0005] While these patents and other previous methods have attempted to solve the problem of efficiently and effectively ironing pants with crisp creases, none have employed an insertable device with a handle, a visible guide for aligning with the pants leg seam, and that is disposed for advertising or promotional purposes. Additionally, prior inventions such as the Corby® Pants Presser, do not allow for the rapid ironing of multiple pants.
[0006] Therefore, a need exists for an improved, versatile ironing accessory that can decrease the time for ironing of pants.
[0007] The foregoing patent and other information reflect the state of the art of which the inventor is aware and are tendered with a view toward discharging the inventor's acknowledged duty of candor in disclosing information that may be pertinent to the patentability of the present invention. It is respectfully stipulated, however, that the foregoing patent and other information do not teach or render obvious, singly or when considered in combination, the inventor's claimed invention.
BRIEF SUMMARY OF THE INVENTION
[0008] The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new device and methods for effectively and efficiently ironing pants, and the like, while also providing a platform for promotional purposes. The present invention is intended to be used when pants are to be ironed manually, at a residence, a lodging establishment, such as a hotel/motel, and the like.
[0009] One objective of the present invention is to provide a device that can be used in the ironing process that decreases the time required to correctly iron pants and the like.
[0010] Another objective of the present invention is to provide a device that can be used in the ironing process that is inexpensive.
[0011] Another objective of the present invention is to provide a device that can be used in the ironing process that is easy to use.
[0012] Another objective of the present invention is to provide a device that can be used in the ironing process that can be reused many times.
[0013] Another objective of the present invention is to provide a device that can be used in the ironing process that is enabled for convenient storage.
[0014] Another objective of the present invention is to provide a device that can be used in the ironing process that is disposed for displaying promotional or other identification type of information.
[0015] Another object of this invention is to provide a device that can be used in the ironing process which uses simple materials and components.
[0016] Another objective of the present invention is to provide a method for the ironing of pants and the like that takes the guesswork out of creating creases correctly.
[0017] Another objective of the present invention is to provide for securing the invention to an ironing board or other object.
[0018] The basis for the present invention is centered on a generally V-shaped part suitable for insertion into the leg of a pair of pants, having an area available for advertising, decoration or promotion on the front and back, and that is operable for the ironing of pants and the like.
[0019] The present invention is comprised of a roughly V-shaped part made of a material that can be used in the ironing of pants and the like. This V-shaped part can be made in a variety of sizes, such as, but not limited to, small, medium and large. The present invention is further comprised of an oblong hole near the top of the invention that can serve as a handle for insertion and removal of the invention into and out of a pants leg. The present invention is further comprised of a visible marking on the front side of the invention that is centered vertically on the invention and extends the entire length of the front side of the invention. The thickness of the present invention is between 1/32th inch and ⅛ th inch. The present invention is further comprised of a foldable area that is located at the mid-point of the invention and extends horizontally the entire width of that portion of the invention. The present invention is further comprised of a roughly circular hole in the upper left corner of the front of the invention. The present invention is further comprised of a securing attachment that engages this circular hole and is enabled for securing the invention to an ironing board or other suitable object. The present invention can be made in different colors, with different patterns and with promotional, advertising or identification information on the front side, the back side, or both sides.
[0020] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[0021] As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
[0022] Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0023] Further objects and advantages of the present invention will be apparent from the following detailed description of a presently preferred embodiment which is illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0024] Other advantages and features of the invention are described with reference to exemplary embodiments, which are intended to explain and not to limit the invention, and are illustrated in the drawings in which:
[0025] FIG. 1 is a front view of the invention.
[0026] FIG. 2 is a back view of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Before explaining the disclosed embodiment of the present invention in detail it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
[0028] The preferred embodiment of the present invention is comprised of the following. The ironing accessory, 010 , has a top side, 080 , a bottom side, 090 , a left side, 100 , a right side, 110 , a front side, 120 and a back side, 130 , with the front side, 120 and the back side, 130 , being roughly co-planar with each other. The ironing accessory, 010 , is made of a material that is suitable for the manual ironing of pants, such as, but not limited to heat resistant plastic. The ironing accessory, 010 , is further comprised of a hand-hold area, 020 , which is a roughly oblong hole positioned close to the top center of the ironing accessory, 010 . The shape of the hand-hole area, 020 , can vary and may have depressions that correspond to the fingers of a person's hand, or the exposed edges of the hand-hold area, 020 , may be covered with an additional substance or material. The ironing accessory, 010 , is further comprised of a seam guide, 030 , that is vertically positioned in the center of the front side, 120 , of the ironing accessory, 010 and extends from the top side, 080 , to the bottom side, 090 of the ironing accessory, 010 . The alignment marking can be a dashed line, a solid line, a series of symbols or patterns, or other suitable markings. The ironing accessory is further comprised of a folding area, 140 , that is positioned roughly half way between the top side, 080 and the bottom side, 090 , and extends horizontally from the left side, 100 , to the right side, 110 , and is enabled for folding such that the ironing accessory, 010 , can be folded for convenient storage or placement into a suitcase. The ironing accessory is further comprised of a security hole, 040 , that is positioned near the top left corner of the ironing accessory, 010 . The ironing accessory is further comprised of a security line, 050 , that goes through the security hole, 040 , wherein the security line, 050 has a top theft-resistant attaching means, 060 , and a bottom theft-resistant attaching means, 070 . Said security line can be a lanyard attachment made of a durable nylon cord, with zip-tie style connectors.
[0029] The preferred embodiment of the invention is made as follows. A roughly V-shaped form is fashioned out of a suitable material, such as flexible, heat-resistant plastic. The top side, 080 , is approximately 16 inches long, the bottom side is approximately 8 inches long, the left side, 100 , and the right side, 110 , are approximately 48 inches long. The top of the hand-hold area, 020 , is approximately 1 inch from the center of the top side, 080 . The size of the hand-hold area, 020 , is roughly 2 inches in height and 4 inches in length. The size of the security hole, 040 , is roughly ½ inch in diameter. The seam guide, 030 , for the preferred embodiment is a dotted line that goes from the center of the top side, 080 , vertically to the center of the bottom side, 090 , and is preferably placed on the front side, 120 , of the ironing accessory, 010 , by the mold creating the form. The thickness of the ironing accessory material is preferably 1/16 th inch and the material is flexible enough that the ironing accessory can be folded with the bottom side, 090 , touching the top side, 080 , for storage or placement within a suitcase for traveling.
[0030] The preferred method of using the invention for ironing and creasing pants is comprised of the following steps.
1. Lay the pants, trousers, or shorts on an ironing board or any flat surface. 2. Grab the invention in one hand by the hand-hold area, 020 , and the waist of the pants in the other hand. 3. Align the outside seam of the pants with the dotted seam guide, 030 . 4. Slide the invention down the pants leg until the pants leg becomes taunt. (This automatically aligns the edges of the invention with the creases in the pants). 5. Iron both sides of the pant leg. (The individual has the choice of whether or not to use starch). 6. Once the leg is sufficiently ironed, grab the invention in one hand by the hand-hold area, 020 , and pull it out of the pants leg.
[0037] The preferred method of using the invention for ironing and not creasing pants is comprised of the following steps.
1. Lay the pants, trousers, or shorts on an ironing board or any flat surface. 2. Grab the invention in one hand by the hand-hold area, 020 , and the waist of the pants in the other hand. 3. Align the outside seam of the pants with the left side, 100 , of the invention. (The dotted seam guide, 030 , will be aligned with the center of the pants leg). 4. Slide the invention down the pants leg until the pants leg becomes taunt. (This automatically aligns the edges of the invention with the creases in the pants). 5. Iron both sides of the pant leg. (The individual has the choice of whether or not to use starch). 6. Once the leg is sufficiently ironed, grab the invention in one hand by the hand-hold area, 020 , and pull it out of the pants leg.
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The invention concerns an ironing accessory and an ironing method. The ironing accessory comprises a roughly V-shaped insert for a pants leg. The ironing accessory is further comprised of an area that serves as a handle, is enabled for theft-deterrence, and has a visual guide for alignment with the pants seam or the middle of the pants leg. The front and back of the device is disposed for promotional, advertising or identification information. The methods are for ironing pants using the device.
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TECHNICAL FIELD
This invention pertains generally to gas sensors, and more specifically to a control system for controlling an operating temperature of an exhaust gas sensor.
BACKGROUND OF THE INVENTION
Sensors are used in control systems of internal combustion engines and other combustion devices to measure operating parameters and constituents of a resulting feedstream. Sensor information is provided to a controller that can control an incoming feedstream or trigger an alarm based upon the measured parameter or constituent. For example, an exhaust gas sensor in a control system of an internal combustion engine is used to measure the parameter of air/fuel ratio. An engine controller can then use the air/fuel ratio information to control the feedstream that flows through the engine and into an aftertreatment system, such as a catalytic converter. A properly controlled gas feedstream is important for complete operation of the exhaust aftertreatment system during light-off and steady-state warmed-up operation of the control system.
A control system must have accurate, timely feedback from the feedstream to effectively control a device such as an engine. Optimal performance of an exhaust aftertreatment system relies upon a controlled, predictable feedstream. Precise control of the exhaust gas feedstream is becoming more important with the implementation of new engine technologies, including direct injection fuel injection systems and lean-burn control systems.
A sensor takes a certain amount of time to warm up and become fully operational. The amount of time to full operation is affected by the power delivered to a heating element of the sensor and the heat transferred between the sensor by the feedstream and the surrounding environment, including any heat transferred from a mounting structure for the sensor.
The ability to maintain the sensor at a target operating temperature leads to more precise output of the sensor in systems wherein the sensor output is dependent upon the operating temperature. A specific example of an interaction between the operating temperature and measurement ability of a sensor is a zirconium-oxide exhaust gas sensor that is used for internal combustion engine control and diagnostics. The output of the sensor varies as a function of the sensor's operating temperature when measuring in a rich air/fuel region. The voltage output of the zirconium-oxide exhaust gas sensor is a function of the partial pressure of oxygen in the feedstream compared to a reference value, and the operating temperature of the zirconium-oxide cell. This has been described using the Nernst equation, which is a governing equation for a zirconium-oxide exhaust gas sensor:
Sensor Output, V SEN (volts)= K*T S *Ln([ P (O 2 ) REF]/[ P (O 2 ) EXHAUST ])
wherein: K=R/(4F) R=Universal Gas Constant (8.315 J/mole-K) F=Faraday Constant (96.485 Coulomb/gmole equiv) T S =Operating Temperature (K) of the Sensor P(O 2 ) REF =partial pressure of Oxygen, in a reference cell P(O 2 ) EXHAUST =partial pressure of Oxygen, in the monitored feedstream.
As can be seen, the operating temperature T S of the sensor directly influences the sensor output, V SEN . A control system can rely more completely on the output of the sensor as a measure of the partial oxygen pressure when the sensor is maintained at a specific temperature. This permits more precise control of the system using the sensor. In the case of the zirconium-oxide oxygen sensor, control of the operating temperature of the sensor which also allows a range of the output of the sensor to be linearized, leading to more precise measurement and control of exhaust gas air/fuel ratio.
The prior art has sought to improve the accuracy, in terms of measurement repeatability, of a gas sensor by adding a heating element to the sensor. The prior art has also sought to control an amount of power delivered to a heating element of a gas sensor so the heating element operates at a specific temperature. It is inferred that the sensor element operates above a minimum temperature, under known conditions. It accomplishes the control of power to the heating element by using basic and auxiliary electric power and relying upon a measure of engine coolant temperature for feedback. This control is primarily focused upon maintaining sensor temperature above a certain level when the system is in a warmed-up operating condition. The prior art has also controls the heating element by measuring an internal resistance of the heating element before and during sensor operation, and controlling the power delivered to the heating element based upon a ratio of the two measured resistances. This strategy heats a sensor to a predetermined temperature using information from the heating element as feedback. The prior art does not control temperature and operation of the sensor based upon any external effects, including heat transfer from the feedstream environment and the sensor mounting structure. The prior art also does not use a physical model to assist in determining the sensor temperature.
Therefore, there is a need to improve the measurement accuracy, repeatability and durability of a sensor by compensating for any effect on operating conditions due to changes in the sensor environment. There is a need to compensate for any effect on sensor temperature caused by changes in the gas feedstream or due to heat transfer between the sensor and a mounting structure for the sensor. There is also a need to determine and control heat energy transfer to a sensor during sensor warm-up.
SUMMARY OF THE INVENTION
The present invention is an improvement over conventional gas sensor heating element control systems in that it provides a method and apparatus to determine the sensor operating temperature based upon an electrical heat input to the sensor, the gas feedstream temperature, and the mounting structure of the sensor. The method and apparatus control the gas sensor to a target operating temperature, using a control strategy and control system. The present invention relies upon a heating model, and feedback and model-based feedforward control systems to achieve and maintain the sensor at the target operating temperature. This includes providing a gas sensor with a controllable heating element which is preferably a resistive device. The gas sensor is operable to measure a parameter of the gas feedstream. The control strategy employs a control system for the heating element that is based upon the target operating temperature, the temperature of the heating element, and an effect of the feedstream and mounting structure on the temperature of the sensor. The control strategy enables the control system to optimize the heating of a sensor during a warm-up period, but still prevent overheating of the sensor. The control strategy determines the external effects of the feedstream and mounting structure on the temperature of the sensor by employing a feedforward disturbance rejection that is based upon a determination of heat transfer from the feedstream and a sensor mounting structure.
The target operating temperature of the sensor can be a maximum operating temperature, or a steady-state operating temperature that is less than maximum, or it can be a predetermined operating temperature. When the control strategy operates at a predetermined operating temperature, it employs heating element control techniques that address the specific operating characteristics of the system. For example, a control strategy may have a goal to operate at a sensor temperature below a maximum operating temperature, in order to allow the system to be able to accommodate variations in other areas that influence the sensor operating temperature. This includes variations caused by changes in the temperature of the feedstream, or variations in system voltage levels. A control strategy may instead seek to limit the time-rate change in temperature of the sensor during a warm-up period. The desire to limit the warm-up rate can be based upon concerns for sensor durability, or concerns for changes in feedstream during the warm-up period. One such change in the feedstream occurs when the sensor is used to measure an output from a combustion process, as when the sensor is used to monitor an output from an internal combustion engine. Water is created as a byproduct of combustion and results in airborne water droplets, especially during the warm-up period. The water droplets impinge upon a sensor and cause thermal shock of the sensor element or external shield. A limit on the warm-up rate of the sensor improve the durability of the sensor by reducing a risk of thermal shock and material degradation caused by water impingement. A limit in the warm-up rate may also be based upon a need to manage electrical energy consumption in the system. The control system limits power delivered to the sensor at initial startup and other times when the system does not require the sensor to be operational.
The feedback system of the invention is based upon the need to control the sensor to the target operating temperature. The temperature of the sensor is inferred from the temperature of the controllable heating element. The feedback system is configured to measure the temperature of the controllable heating element during normal operation, and provide the temperature as feedback to the control system. The controller uses an output device that is capable of providing a pulsewidth-modulated power output to the controllable heating element, and also capable of measuring an impedance of the controllable heating element when no power is being output. The controller converts the impedance of the controllable heating element to a temperature measurement, based upon a predetermined calibration of impedance versus temperature. The feedback system also includes a method to compensate for changes in impedance over time due to system aging. The feedback system measures the resistance of the heating element when the temperature is a known value. This is done when the system is not operating and the ambient temperature can be determined with another sensor, such as before a cold starting event.
The required heat to be transferred to the sensor for the sensor to reach the target operating temperature is determined next, based upon the measured temperature of the controllable heating element. The control strategy also uses the external feedforward system to control the temperature of the sensor while accounting for the amount of heat transferred between the sensor, the feedstream, and the mounting structure.
The external feedforward system is based upon the physical relationship between the sensor, the feedstream, and the mounting structure. The physical relationship affects the operating temperature and therefore the output signal of the sensor. The feedforward system measures the feedstream and determines an amount of heat that is transferred between the sensor, the feedstream, and the mounting structure. The magnitude of heat transfer between the sensor and feedstream is determined with information that is available to the control system. The characteristics of greatest importance for heat transfer in the system include mass flow and temperature of the feedstream. Values for mass flow and temperature are measured or inferred, and a thermal model is created that is used by the control system to determine the effect of heat transfer on the operating temperature of the sensor.
The control strategy uses the control system to maintain the operating temperature of the sensor, based upon the feedback and feedforward systems. The control strategy determines the amount of heat that must be transferred to the sensor using the controllable heating device. It does this by adding the heat transfer that is determined by the feedforward system to the required heat transfer, as determined by the feedback system. The control strategy then uses the resulting heat transfer to control the power to the controllable heating element.
The present invention also provides an improvement over conventional engine control devices in that it is a method for controlling the heating element of a sensor during a cold starting event. The method includes estimating a temperature of the sensor based upon the amount of heat transfer between the sensor and the feedstream, the mounting structure, and the controllable heating element. The method operates the controllable heating element at maximum power until it is determined that the estimated temperature of the sensor is near a targeted temperature.
The present invention also provides an improvement over conventional engine control devices in that it is a method to provide an exhaust gas sensor with a linear output that corresponds to a change in air/fuel ratio. The invention is based upon the concept that an output from an exhaust gas sensor is repeatable over a range of air/fuel ratios when the sensor is operated at a specific, known temperature. The invention includes providing a gas sensor in an exhaust gas feedstream with a controllable heating element. The method operates by first calculating an effect by the feedstream on a temperature of the exhaust gas sensor by the feedstream, using a feedforward system, and determining a temperature of the controllable heating element. The method then maintains the exhaust gas sensor at the known temperature by controlling the controllable heating element, based upon the temperature of the controllable heating element and the calculated effect of the feedstream on the temperature of the exhaust gas sensor. When the air/fuel ratio is at or near lambda=1.0, the sensor is typically operable to accurately measure the air/fuel ratio over a range of +/−3% lambda.
The present invention also provides an improvement over conventional engine control devices in that it provides an exhaust gas sensing system controllable to a targeted temperature. This includes having an exhaust gas sensor with a controllable heating element operably attached to a controller. The exhaust gas sensor is in a feedstream and the controller is able to determine at least one operating parameter of the feedstream. The controller also calculates an effect on a temperature of the exhaust gas sensor, based upon the operating parameter, and determines a temperature of the controllable heating element. The controller controls the controllable heating element based upon a targeted temperature of the exhaust gas sensor, the temperature of the controllable heating element, and the calculated effect on the temperature of the exhaust gas sensor. These and other objects of the invention will become apparent to those skilled in the art upon reading and understanding the following detailed description of the embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and arrangement of parts, the preferred embodiment of which will be described in detail and illustrated in the accompanying drawings which form a part hereof, and wherein:
FIG. 1 is a schematic of an exhaust gas sensor in an operating environment, in accordance with the present invention;
FIG. 2 is a schematic of an exhaust gas sensor and an electrical circuit, accordance with the present invention;
FIG. 3 is a schematic of a heating model, in accordance with the present invention;
FIG. 4 is a schematic of a closed-loop control model, in accordance with the present invention; and
FIG. 5 is a schematic of a heating model, in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein the showings are for the purpose of illustrating an embodiment of the invention only and not for the purpose of limiting the same, FIG. 1 shows an exhaust gas sensing system controllable to a predetermined temperature which has been constructed in accordance with an embodiment of the present invention. The system includes an exhaust gas sensor 20 comprising a sensing element 22 and a controllable heating element 24 that is operably attached to a controller 10 . The controller 10 has an output device 12 that is operably attached to the controllable heating element 24 . There is a signal, V SEN , that is the output of the sensing element 22 and is input to the controller 10 over signal line 13 . In this embodiment, the exhaust gas sensor 20 is mounted in an exhaust feedstream 26 of an internal combustion engine (not shown) that is controlled by the controller 10 . The sensor is mounted in an exhaust pipe on a mounting structure 28 that can comprise a threaded mounting boss or another device suitable for mounting a sensor in the exhaust feedstream. The internal combustion engine has various other sensors and output devices that are monitored and controlled by the controller 10 .
The controller 10 contains algorithms and calibrations (not shown) and gathers information from the various sensors (not shown). The controller then controls the output devices (not shown) and manages the feedstream through the internal combustion engine based upon the algorithms, calibrations, and information from the various sensors (not shown). The feedstream that flows into the engine (not shown) determines the exhaust feedstream 26 out of the engine. The controller 10 uses an output from the exhaust gas sensing element 22 to control the exhaust feedstream 26 . The internal combustion engine (not shown), controller 10 with algorithms and calibrations, and the sensor 20 in the exhaust feedstream 26 are well known to one skilled in the art.
The feedstream 26 in this embodiment comprises an exhaust gas feedstream that is a waste product output from a combustion process of the internal combustion engine (not shown). The feedstream 26 is characterized by parameters that include mass flowrate, temperature, air/fuel ratio, and by concentrations of various gas constituents. The gas constituents can include hydrocarbons, carbon monoxide, nitrides of oxygen, and other gases that are regulated by various federal or state emissions laws and regulations. The gas constituents can also include unregulated gases, e.g. oxygen and carbon dioxide. The characterization of the gas feedstream in terms of parameters and constituents is well known to one skilled in the art.
The sensing element 22 of the sensor 20 of this embodiment is comprised of zirconium oxide and is operable to measure a parameter of the feedstream 26 , preferably a partial pressure of oxygen. Alternatively the sensing element 22 can be operable to measure the air/fuel ratio of the feedstream 26 over a wide range. Alternatively, the sensing element 22 can be operable to measure constituents of the feedstream 26 , including, for example nitrogen (N 2 ), carbon dioxide (CO 2 ), carbon monoxide (CO), or hydrocarbons (HC). The heating element 24 is comprised of an electrical resistive element or a positive temperature coefficient electrical resistive element, and is electrically connected to the output device 12 of the controller 10 using an electrical wiring harness 25 . There is a relationship between the resistance and a temperature of the heating element 24 that can be determined during development of the sensor 20 and is consistent from part to part. This relationship is stored in the controller 10 for use by an engine control system (not shown).
The output device 12 of the controller 10 is preferably a device that is operable to deliver a controlled amount of electrical power to the heating element 24 in the form of a pulsewidth modulated (‘PWM’) signal in response to a control signal, V CTRL from the controller. The PWM signal, V PWM , is preferably a square wave signal that alternates between zero voltage and system voltage V SYS at a given frequency. The amount of power that is delivered by the output device 12 to the controlled heating element 24 is determined by the frequency of the PWM signal and a percentage of time during each cycle that the voltage level is at the system voltage V SYS . The sensor 20 with the output device 12 , the PWM controlled heating element 24 , and the controller 10 are well known to one skilled in the art.
Referring now to FIG. 2 , a temperature, T HTR , of the heating element 24 can be determined using the output device 12 that is electrically attached to the controller 10 . The output device 12 is comprised of a field effect transistor 40 with a gate 42 , source 44 , and drain 46 . The gate 42 is electrically connected to the controller and receives the PWM signal V CTRL . The source 44 of the field effect transistor 40 is electrically connected to the system voltage, V SYS . The drain 46 of the field effect transistor 40 is electrically connected to the controller 10 such that the controller is operable to measure the voltage V PWM that is delivered to the heating element 24 . There is a circuit that is comprised of the system voltage, V SYS , a reference resistor 48 , the heater circuit 25 , and the heating element 24 in series with an electrical ground 19 . The controller 10 is also operable to measure V SYS . The controller determines the heating element resistance R HTR during a time when V CTRL is at zero voltage, i.e. when no power is being delivered to the heating element 24 . The controller 10 determines the total resistance of the heater circuit 25 and the heating element 24 by applying Ohm's Law to the measured values, V SYS and V PWM , and the reference resistor 48 . The resistance of the heater circuit 25 is calibrated in the controller 10 , and the controller then determines the resistance of the heating element 24 by subtracting the resistance of the heater circuit 25 from the total resistance. The controller 10 also contains a calibration with which it can convert the resistance of the heater circuit 25 into the temperature value, T HTR . The controller 10 also measures R HTR during a time when the engine is not operating and when it is known that the temperature of the exhaust feedstream 26 and exhaust gas sensor 20 are at ambient conditions. This is accomplished using input from another temperature sensor that is operably connected to the controller 10 , for example an intake air temperature sensor (not shown) or an engine coolant temperature sensor (not shown). The controller 10 then uses the R HTR value measured at the ambient conditions to calibrate the heating element 24 . The controller 10 also uses the information collected with the output device 12 regarding R HTR to diagnose malfunctions in the circuit 25 and the heating element 24 . The controller 10 also diagnoses when the resistance R HTR falls outside a range of expected values, which indicates a short circuit, an open circuit, or deterioration in the heater circuit 25 .
Referring now to FIG. 3 , a heating model for determining a temperature of the sensing element 22 is shown that is in accordance with the present invention. In this embodiment, the heating model that is shown is for use with the exhaust gas sensor 20 of the internal combustion engine previously referred to with respect to FIGS. 1 and 2 . The heating model is implemented in the controller 10 using algorithms, inputs from sensors and the electrical circuits as shown in FIGS. 1 and 2 , and is executed during a loop cycle, in this embodiment a 100-millisecond loop. Each of the determinations and calculations described herein are executed in an ordered fashion. The implementation of control strategies using a controller 10 is well known to one skilled in the art.
The heating model shown in FIG. 3 comprises a method for determining a temperature of the sensing element 22 in the feedstream 26 . It includes determining an initial temperature of the sensing element 22 . The method then determines an amount of heat transfer between the sensing element 22 and the feedstream, the sensor mounting structure, and the sensor heating element 24 . A net temperature change in the sensor 20 is determined by calculating a time-integral of a sum of the amount of heat transfer between the sensing element 22 and the feedstream 26 , the sensor mounting structure 28 , and the sensor heating element 24 . The net temperature change is added to the initial temperature of the sensing element 22 to determine sensor temperature T S . The heating model is used by an open loop control strategy and a closed loop control strategy to control the temperature of the sensing element 22 .
The initial temperature of the sensing element 22 can be determined as part of detecting that a cold starting event has occurred. The initial temperature of the sensing element 22 is determined based upon the resistance of the controllable heating device, as described previously with respect to FIG. 2 .
The amount of heat transfer Q EXH between the sensing element 22 and the feedstream 26 is determined by calculating a difference between the temperature of the feedstream T EXH and the sensor temperature T S . The difference is then multiplied by a first predetermined heat transfer coefficient F(M EXH ), which is a function of the mass flowrate M EXH of the exhaust feedstream. This is shown in Block 52 . The first predetermined heat transfer coefficient, F(M EXH ) is a measure of the efficiency of heat transfer between the exhaust feedstream 26 and the sensing element 22 . It comprises a calibration array in the controller 10 that is derived and verified experimentally for a given system configuration and representative operating conditions. The calibration array can be a single scalar value, or an array of scalar values wherein a specific value for F(M EXH ) is selected by the controller 10 based upon the operating conditions. The amount of heat transfer between the sensor 20 and the feedstream 26 , Q EXH , can be a negative or a positive value, depending on the relative values of the temperatures of the feedstream and the sensing element 22 .
The measured parameters from the exhaust gas feedstream 26 that are used as inputs to Block 52 include a mass air flowrate, M EXH , an exhaust gas temperature T EXH and sensor temperature T S . The mass flowrate M EXH is determined using existing inputs to the controller 10 . These inputs comprise a direct measurement of incoming mass flow of air, using a mass airflow sensor (not shown) in this embodiment.
The measure of air mass through an internal combustion engine using the mass airflow sensor (not shown) is well known to those skilled in the art. The feedstream temperature T EXH is an estimated temperature value that is derived from engine operation, and is determined from parameters that include engine speed, manifold absolute pressure, exhaust gas recirculation rate, ignition spark advance; coolant temperature and engine operating time. The temperature T M of the mounting structure 28 is an estimated value that is derived from engine operation, and is determined from parameters that include engine operating time, engine coolant temperature, and temperature T EXH of the feedstream 26 . The feedstream temperature T EXH and the mounting structure temperature T M are based upon measured and estimated parameters and are unique to a given combination of engine and vehicle. The determinations of the feedstream temperature T EXH and the mounting structure temperature T M are known to one skilled in the art.
The amount of heat transfer, Q MOUNT between the sensing element 22 and the sensor mounting structure 28 , is determined by calculating a difference between the temperature of the mounting structure T M and the sensor T S . The difference is multiplied by a second predetermined heat transfer coefficient K M to determine the total heat transfer during the time period of the cycle of operation described previously. This is shown in Block 50 . The second predetermined heat transfer coefficient K M is a measure of the efficiency of heat transfer between the sensor mounting structure 28 and the sensing element 22 . The second heat transfer coefficient K M is a calibration value in the controller 10 that is derived and verified experimentally for a given system configuration and representative operating conditions. It can be a single scalar value, or an array of scalar values wherein a specific value for K M is selected by the controller based upon the operating conditions. The amount of heat transfer between the sensing element 22 and the sensor mounting structure 28 can be a negative or a positive value, depending on the relative values of the temperatures of the sensor mounting structure 28 and the sensing element 22 . The determination of heat transfer indicates whether there is a net transfer of heat energy from the feedstream 26 or the mounting structure 28 into the sensing element 22 , or net transfer of heat energy from the sensing element 22 into the feedstream 26 or mounting structure 28 . Determination of the magnitudes of the heat transfer coefficients, F(M EXH ) and K M is generally known to one skilled in the art.
The amount of heat transfer between the gas sensing element 22 and the sensor heating element 24 is determined by calculating an amount of electrical power transferred to the heating element 24 and multiplying it by a sensor/heating element heat transfer coefficient, K HTR , as shown in Block 54 . The amount of electrical power is determined by calculating a squared value of the voltage V PWM , and dividing by the resistance R HTR of the heating element 24 . The sensor/heating element heat transfer coefficient, K HTR is a measure of the efficiency of heat transfer between the heating element 24 and the sensing element 22 . It comprises a calibration array in the controller 10 that must is derived experimentally for a specific sensor design. The calibration array is typically a single scalar value. Determination of heat transfer values for sensors and heating elements is known to one skilled in the art.
A change in temperature of the gas sensing element 22 is determined by calculating the total heat transfer between the gas sensing element 22 and the feedstream 26 , the sensor mounting structure 28 , and the sensor heating element 24 , as shown in Block 56 . The controller calculates a time-integral of the total heat transfer to determine a change in temperature, as shown in Block 58 . The change in temperature is added to the initial temperature, designated as T S (t O ), to determine the sensor temperature T S as shown again in Block 58 . The sensor temperature T S is stored in the controller 10 for use in the next execution of the heating model or control, which occurs during the next loop cycle.
Referring now to FIG. 4 , a closed-loop control strategy for controlling sensor temperature T S is shown. The closed-loop control strategy uses elements of the heating model described in reference to FIG. 3 . The closed-loop control strategy is executed as part of ongoing operation of the controller 10 , for example within a specific cycle of operation. Each of the determinations and calculations described herein are executed in an ordered fashion. The implementation of closed-loop control strategies using a controller 10 is well known to one skilled in the art.
The intent of the closed-loop control strategy is to control the sensor temperature T S to a predetermined temperature, T TARGET , as shown in block 60 . The resistance R HTR , of the heating element 24 is measured, and the temperature, T HTR , is determined, as described in relation to FIG. 2 . In this embodiment, the temperature, T HTR of the heating element 24 is used as a measure of the sensor temperature T S . The sensor temperature T S is then subtracted from the value for T TARGET (block 62 ). This difference comprises the difference between the targeted temperature of the sensor and the actual temperature of the sensor and is indicative of the amount of heat energy that must be transferred to the sensing element 22 to reach the targeted temperature. The difference (T TARGET −T S ) is used in Block 64 to execute a feedback control strategy and determine a heat transfer value Q FDBK that is output to block 66 .
There is also external heat transfer that is comprised of Q EXH , which is the heat transfer between the sensing element 22 and the feedstream 26 , and Q MOUNT , which is the heat transfer between the sensing element 22 and the sensor mounting structure 28 . These heat transfer values are described previously with reference to FIG. 3 . The heat transfer value Q FDBK is adjusted by the external heat transfer values Q EXH and Q MOUNT , as shown in Block 66 . The system determines the amount of power P PWM to deliver to the heating element 24 based upon an adjusted heat transfer value, (Q FDBK −[Q EXH +Q MOUNT ]), as shown in Block 68 . The power delivered to the heating element 24 is in the form of a PWM electrical signal from the output device 12 of the controller 10 , as described previously.
The targeted temperature T TARGET shown in Block 60 is determined during development of the control system that uses the sensor 20 . In this embodiment the system is an internal combustion engine (not shown) and the targeted temperature T TARGET is determined during engine development and calibration. The targeted temperature T TARGET is based upon operating conditions of the system, location of the sensor 20 in the feedstream 26 , and other factors related to the design of the control system and hardware.
The closed-loop control strategy may include a requirement that T S be maintained at a maximum operating temperature at all times during engine operation. T TARGET is then made equal to the maximum operating temperature at all times during engine operation. When the internal combustion engine is started, T S may be significantly below the maximum operating temperature. The closed-loop control strategy then commands the controller 10 to maximize the amount of power P PWM being delivered from the output device 12 to the heating element 24 during initial operation of the engine (not shown). This happens during a cold start of an engine, for example. When a cold starting event is detected and there is a requirement that T S be maintained at a maximum operating temperature, a warm-up strategy is executed as described hereinafter.
The closed-loop control strategy may intend that T S increase at a specific time-rate that is less than maximum, as a method to manage electrical power consumption. In this instance, the closed-loop control strategy controls the predetermined temperature T TARGET such that T TARGET increases at a rate that is less than maximum.
The closed-loop control strategy may intend that T S follow a preset pattern for temperature, such as remaining below a specific predetermined temperature level until a specific event has occurred. For example, the control system may be comprised of an exhaust gas sensor 20 positioned downstream from an internal combustion engine (not shown) and catalytic converter system (not shown). The closed-loop control strategy controls the predetermined temperature T TARGET such that the temperature of the sensor, T S , remains below a specific temperature until the catalytic converter system achieves sufficient temperature to become exothermic. This type of strategy is implemented to address concerns related to decreased durability of the sensor 20 caused by water impingement from the combustion process during engine warm-up. The specific temperature of the sensor T S below which the closed-loop control strategy controls the sensing element 22 can be determined during engine and system development, prior to regular production.
Referring again to FIG. 4 , the targeted temperature T TARGET is determined for the exhaust gas sensing element 22 as shown in block 60 and described previously. The temperature of the sensor, T S , is also determined as described previously, and is subtracted from T TARGET (Block 62 ). The difference is indicative of the total amount of heat energy that must be transferred to the sensing element 22 to reach the targeted temperature T TARGET . The difference (T TARGET −T S ) is used in Block 64 to execute a feedback control strategy and determine the heat transfer value Q FDBK that is output to block 66 . The use of feedback control strategies is well known to one skilled in the art.
Referring again to FIG. 4 , the closed-loop control strategy then adjusts the heat transfer value Q FDBK by the external heat transfer value Q EXT , as shown by Block 66 . The adjusted heat transfer value, (Q FDBK −[Q EXH +Q MOUNT ]) is used by the controller 10 to determine the amount of power P PWM to deliver to the heating element 24 , as shown in Block 68 . The power is delivered to the heating element 24 using the output device 12 . Deriving an amount of power delivered to the heating element 24 using a PWM electrical signal is well known to those skilled in the art.
Referring now to FIG. 5 , a warm-up strategy is now described, based upon the heating model shown in FIG. 3 . It is shown for use with the exhaust gas sensor 20 of the internal combustion engine previously referred to with respect to FIGS. 1 and 2 . The warmup strategy of FIG. 5 comprises detecting a cold starting event, and maximizing the amount of electrical power P PWM delivered to the sensing element 22 , until an estimated sensor temperature T S-EST has reached 90% of a maximum operating temperature. The estimated sensor temperature T S-EST is used as a substitute for the sensor temperature T S , during operation of the warm-up strategy. The heating model is implemented in the controller 10 using algorithms, inputs from sensors and electrical circuits as shown in FIGS. 1 and 2 , and is executed during a loop cycle, in this embodiment a 100-millisecond loop. Each of the determinations and calculations described herein are executed in an ordered fashion. The implementation of control strategies using a controller 10 is well known to one skilled in the art.
The warmup strategy shown in FIG. 5 uses inputs from the engine to estimate the sensor temperature T S-EST and control the heating of the sensing element 22 . The initial sensor temperature is determined as described previously, and is designated in Block 58 as T S (t O ). The controller 10 is operable to detect an occurrence of a cold starting event of the engine using information from other input devices, for example an intake air temperature sensor (not shown) and an engine coolant temperature sensor (not shown). Detecting when a cold starting event occurs is well known to one skilled in the art. When a cold starting event is detected, the controller 10 maximizes the amount of electrical power P PWM that is delivered to the heating element 24 by operating at or near a PWM duty cycle of 100%. The controller 10 estimates the sensor temperature T S-EST by executing the heating model each loop cycle, as described previously. The controller 10 employs the warm-up strategy until it has determined that the sensor has reached a targeted temperature value. The estimated sensor temperature T S-EST is used in place of the sensor temperature T S for determination of the heat transfer Q EXH between the sensing element 22 and the feedstream 26 , and for determination of the heat transfer Q MOUNT between the sensing element 22 and the sensor mounting structure 28 . In this embodiment, the controller 10 employs the warm-up strategy until the estimated sensor temperature T S-EST has reached 90% of a maximum allowable operating temperature. The controller 10 reduces the power P PWM that is delivered to the heating element when it has determined that the estimated sensor temperature T S-EST has reached 90% of the maximum operating temperature. The controller 10 then discontinues use of the warm-up strategy and begins employment of the closed-loop control strategy at that time.
The invention also comprises a method for providing an exhaust gas sensor 20 with a linear output that corresponds to a change in air/fuel ratio in the feedstream 26 , using the closed-loop control strategy, shown in FIG. 4 . When the exhaust gas sensing element 22 is a zirconium-based sensor, the invention again comprises providing the exhaust gas sensor 20 , including the sensing element 22 and the controllable heating element 24 in an exhaust feedstream 26 . The method includes monitoring at least one parameter of the feedstream 26 and calculating an effect on sensor temperature T S based upon the at least one parameter of the feedstream 26 using the feedforward system, as described previously. The closed-loop control strategy determines T TARGET for the exhaust gas sensing element 22 , and controls the controllable heating element 24 . Accordingly, control of the heating element 24 is based upon the temperature of the controllable heating element 24 and the calculated effect on the temperature of the exhaust gas sensing element 22 , such that the exhaust gas sensing element 22 is operated at the targeted operating temperature.
The targeted operating temperature of the sensing element 22 can be preset in the controller 10 , or it can be determined by the controller 10 based upon the operating conditions. When the targeted operating temperature is preset, there is a specific temperature range at which the controller 10 intends the sensing element 22 to operate. The controller 10 then heats the sensing element 22 to the specific temperature range using the control strategy described in FIG. 3 and the mechanization described in FIG. 1 and FIG. 2 . For example, it may be decided to operate the sensing element 22 at 500° C.+/−20° C., based on various considerations, including wiring harness design, power consumption, sensor design, location of the sensor in the feedstream, and durability. The controller 10 then identifies the targeted operating temperature range, and the closed-loop control strategy operates to maintain the sensor at that temperature. The controller 10 uses a predetermined calibration that can determine a value for air/fuel ratio based upon the output of the sensing element 22 , when the sensing element 22 is operating within the specific temperature range. This value for air/fuel ratio is then used by the engine control system (not shown) to control the internal combustion engine (not shown). Control of an internal combustion engine based upon a measure of air/fuel ratio is well known to those skilled in the art.
Although this is described as a control system for a gas sensor in an exhaust feedstream of an internal combustion engine, it is understood that alternate embodiments of this invention can include any control system that uses a gas sensor in a feedstream wherein the sensor is heated with some form of heating device. The invention describes a heating device that is a resistance temperature device that is driven by a pulsewidth-modulated electrical signal, but the invention comprehends other sensor heating devices and circuits. It is also understood that the invention can include a sensor that is used for diagnostic purposes as well as control purposes, and that the sensor can be located in any appropriate location wherein the sensor can effectively measure the feedstream. It is understood that the controller 10 described in the invention can include more than one physical controller to accomplish the described invention. It is understood that the closed-loop control strategy can be implemented using any combination of software algorithms, electrical circuits, mechanical devices, calibrations and preset conditions.
With regard to the measurement of air mass, the invention includes an inferred measurement of air mass referred to as speed-density. The speed-density calculation is based upon a measure of engine operating parameters including, for example, manifold pressure, engine rotational speed, and throttle position.
With regard to the temperature T S of the sensor, 20 , the invention also includes the use of a sensor wherein T S is determined based upon the temperature of the heater, T HTR . In this embodiment, there is a predetermined method that is used by the controller to derive a value for T S given a measured value for T HTR along with other measured parameters.
With regard to determination of heat transfer to the sensing element 22 , the method includes other methods of determining the temperature of the mounting structure 28 such as a direct measurement of the temperature of the mounting structure 28 . With regard to determination of heat transfer to the sensing element 22 , the method also includes other methods of determining the heat content of the feedstream 26 , such as more direct measurement of the temperature of the feedstream 26 . It is also understood that the determination of heat transfer includes all means of heat transfer, i.e. radiant, conductive, and convective means, and the method is not meant to focus on any single heat transfer means.
With regard to the method of gaining a linear output from the sensor that corresponds to a change in air/fuel ratio by controlling the sensor to a preset temperature, the invention includes the ability to operate at more than one preset temperatures, based upon operating conditions of the system. The controller monitors the operating conditions to evaluate an overall capability to maintain the sensor within the targeted operating temperature range. The controller then selects a targeted operating temperature range of the sensing element 22 that is less than a maximum operating temperature, and the closed-loop control strategy controls the operating temperature of the sensor accordingly. The controller linearizes the output of the sensor when the sensor operates within the targeted operating temperature range, based on predetermined calibrations. In so doing, the controller determines a value for air/fuel ratio based upon the linearized output of the sensor.
The invention has been described with specific reference to the preferred embodiments and modifications thereto. Further modifications and alterations may occur to others upon reading and understanding the specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the invention.
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The invention provides a control strategy and a control system to control a gas sensor to a target operating temperature. It relies upon both feedback and model-based feedforward control systems to achieve and then maintain the sensor at the target operating temperature. The mechanization includes a gas sensor with a heating element in a feedstream. The control strategy employs a control system for the heating element that is based upon the target operating temperature, the temperature of the heating element, and an effect of the feedstream and mounting structure on the temperature of the sensor. The control strategy enables the control system to optimize the heating of a sensor during warm-up and steady state operations.
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FIELD AND BACKGROUND OF THE INVENTION
[0001] The present invention relates to a snap-in coupling for releasably connecting a first structural member and a second structural member.
[0002] DE 198 36 108 A1 discloses a snap-in coupling comprising an elastically deformable female coupling member and a male coupling member. The female coupling member is adapted to be inserted into a socket provided at said first structural member so as to be positively retained therein. It comprises a spherical female portion, an annular intermediate wall integral therewith and serving as an insertion portion, and a tubular outer wall integral with said intermediate wall, which outer wall engages a peripheral wall of the socket when the female coupling portion is inserted into the socket. The male coupling member comprises a head portion and a mounting portion adapted to be fixed to the second structural member.
[0003] In this prior snap-in coupling the intermediate wall of the female coupling member is of conical shape and is stiffened by webs which extend between the tubular outer wall of the female coupling member and which are connected to the outside of the spherical female portion by radial ribs. The female coupling member is made of thermoplastic elastomeric material or rubber. This snap-in coupling has vibration dampening characteristics due to its geometry and the used material so that it provides for vibration decoupling between the first and second structural members.
[0004] German Utility Model 202 16 836 discloses a snap-in coupling wherein the annular intermediate wall of the female coupling member is not of conical shape but of an undulated or corrugated profile. This provides for resiliency not only in axial directions but also in radial directions. Therefore the female coupling member may perform vibration decoupling compensation movements both in axial and radial directions and, accordingly, in all directions therebetween, i.e. three-dimensional compensation movements in space.
[0005] This allows to make the female coupling member of relatively hard plastic material, for example an elastomeric material on the basis of chemically and thermally deformation resistant polyester. For example polybutylenetherephthalate (PBT) and polyethylenetherephthalate (PET) may be used.
[0006] These materials are of temperature dependent hardness. For example, when they are subject to extremely low temperatures down to −40° C. to be encountered in cold climatic zones they will become so hard that the snap-in coupling cannot be released by acceptable forces. Apart from the fact that the mounting and releasing forces are dependent on temperature it is relatively difficult to precisely set the absolute values of the mounting and, respectively, releasing forces for normal environmental conditions because the characteristics of the used plastic material as well as the geometry of the plastic female coupling member cannot be readily controlled.
SUMMARY OF THE INVENTION
[0007] It is an object of the present invention to provide a snap-in coupling wherein the forces for closing and opening of the snap-in coupling are substantially not dependent on temperature in a temperature range from about −40° to 150° C. and furthermore may be precisely controlled as to their absolute values. Furthermore, the snap-in coupling is to have vibration decoupling characteristics similar to those of the snap-in couplings in the prior art.
[0008] A snap-in coupling in accordance with the present invention has been defined in claim 1 .
[0009] In the snap-in coupling of the present invention the female coupling member comprises a plastic support member and a metallic spring clamp. The spring clamp of the female coupling member and the head portion of the male coupling member are formed such that they provide for a snap-in connection frictionally joining the two coupling members when they are inserted into each other.
[0010] Use of a spring clamp which is preferably made from spring steel provides for the advantage that the mounting and dismounting forces of the snap-in coupling are substantially independent of temperature within the above mentioned temperature range. This results from the fact that the characteristics of the material and in particular the spring rate of the metallic spring clamp are substantially constant within said temperature range.
[0011] A further advantage of the present invention is that the absolute values of the mounting and dismounting forces of the snap-in coupling may be very precisely controlled and set by spring clamp characteristics such as material thickness, type of material, geometry, etc. The forces for closing and opening a certain snap-in coupling, therefore, are substantially less responsive to variations of the characteristics of the used plastic material than in the prior art.
[0012] Since the female coupling member consists not only of the metallic spring clamp but additionally of a plastic support member, the support member may be designed such that the snap-in coupling of the present invention will show substantially the same vibration decoupling characteristics as the above mentioned conventional snap-in couplings. Therefore the snap-in coupling of the present invention combines the advantageous properties of a metallic spring clamp and the vibration decoupling characteristics of a plastic coupling member.
[0013] While the spring clamp could be connected to the support member of the female coupling member so as to be releasable, preferably they are fixedly connected to each other by having a base plate of the spring clamp embedded in plastic material of the support member by injection moulding.
[0014] Preferably the spring clamp has a plurality of circumferentially spaced spring arms which snappingly engage the head portion of the male coupling member to provide said snap-in connection. The ends of the spring arms each comprise a holding portion and an insertion portion which are angled with respect to each other in V-shaped relationship. The head portion of the male coupling member has an annular groove matingly shaped with respect to the ends of the spring arms. As a result the insertion portion and the holding portion of the spring arms of the spring clamp may be shaped differently such that a smaller force is required to close the snap-in connection than to open the snap-in connection.
[0015] Preferably the support member of the female coupling member is made of a thermoplastic elastomeric material of optimal chemical and thermal deformation resistance while the spring clamp, as mentioned above, may be made of spring steel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:
[0017] FIG. 1 is a longitudinal section through a snap-in coupling of the present invention in its mounted and closed condition;
[0018] FIG. 2 is a longitudinal section through the female coupling member of the snap-in coupling in its disassembled condition;
[0019] FIG. 3 is a top view of the female coupling member in FIG. 2 ;
[0020] FIG. 4 is a perspective view of the female coupling member in FIGS. 2 and 3 from below;
[0021] FIG. 5 is a side elevation of the male coupling member of the snap-in coupling in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The snap-in coupling as shown in FIG. 1 is intended to releasably join a structural member 2 and a structural member 4 which may be for example structural members of an automotive vehicle to be releasably connected to each other. The snap-in coupling consists of a female coupling member 6 and a male coupling member 8 ; the female coupling member 6 may be inserted into a socket 10 of the structural member 2 , and the male coupling member 8 may be fixed to the structural member 4 .
[0023] In the embodiment as shown, the socket 10 is formed by a recess of the structural member 2 which is of part annular or horseshoe-shape so that the female coupling member 6 may be laterally inserted into the socket 10 . In any case the socket 10 may be of a design as shown in the above-mentioned DE 198 36 108 A1 or DE-GM 202 16 836 the disclosure of which is incorporated herein by reference.
[0024] As shown in FIGS. 1 and 2 , the female coupling member 6 comprises a support member 12 and a spring clamp 14 . In the embodiment as shown the support member 12 and the spring clamp 14 are fixedly connected to each other as will be explained in more detail below. As an alternative the spring clamp 14 may be connected to the support member 12 so as to be releasable therefrom, for example by snap-in or clip connection means or by thermal embedding.
[0025] As already mentioned above the support member 12 is made of plastic material, preferably of a thermoplastic elastomeric material, in particular on a polyester base such as polybutylenetherephthalate (PBT) or polyethylenetherephthalate (PET). While these materials are resiliently deformable, they are of a relatively high shore hardness, and excellent thermal deformation resistance (150° C. and more). Furthermore, they are of excellent chemical resistance, in particular diesel oil resistance. The spring clamp 14 is made of a metallic material, in particular spring steel.
[0026] The support member 12 comprises a tubular outer wall 24 adapted to be inserted into the socket 10 , and a central portion 26 which are connected to each other by circumferentially spaced webs 28 , see also FIGS. 3 and 4 . Since the tubular outer wall 24 is of an axial length substantially exceeding that of the central portion 26 , the webs 28 have inclined lower ends (in FIGS. 1, 2 ) and rectilinear upper ends (in FIGS. 1, 2 ).
[0027] As shown in FIG. 3 the webs 28 extend substantially tangentially with respect to a peripheral wall 29 of the central portion 26 . The webs 28 are arranged in pairs such that the webs of any pair are directed in opposite circumferential directions. Due to this structure the webs 28 allow for relative movements between the tubular outer wall 24 and the central portion 26 in radial directions so as to provide for vibration decoupling of the snap-in coupling when in operation.
[0028] In the embodiment as shown the tubular outer wall 24 and the central portion 26 are connected to each other only by the substantially straight webs 28 so as to provide for minimal space requirements of the female coupling member 6 . When more space is available, the outer wall 24 and the central portion 26 could be connected to each other by an annular intermediate wall of undulated or corrugated profile in longitudinal sections as shown and described in the above mentioned DE-GM 206 16 836. Since the shape and arrangement of such an intermediate wall with associated webs have been disclosed in the above German Utility Model in great detail, no further description thereof is required herein.
[0029] The central portion 26 of the support member 12 has on its bottom side (in FIGS. 1, 2 ) a central lens-shaped projection 30 the purpose of which will be explained further below.
[0030] The spring clamp 14 comprises a base plate 34 having a central hole 36 and a plurality of spring arms 38 (four spring arms in the embodiment as shown). The spring arms 38 are integral with the base plate 34 and bent therefrom for more than 90° when they are in a relaxed condition so that they provide for a square periphery in the bottom view of FIG. 3 for uniformly engaging the male coupling member 8 as will explained in more detail below.
[0031] The spring clamp 14 is fixedly connected to the support member 12 by the base plate 34 and a small adjacent part of the spring arms 38 being embedded in the material of the support member 12 as shown in FIGS. 1 and 2 . This is accomplished during manufacture of the support member 12 by injection moulding. A core within the injection-moulding tool holds the spring clamp 14 , and plastic material is injected about the spring clamp. Since plastic material flows also into the central hole 36 of the base plate 34 and since a small part of the spring arms 14 is enclosed by plastic material of an annular projection 32 of the central portion 26 , positive interlocking between the support member 12 and the spring clamp 14 will result.
[0032] As an alternative these members could be connected to each other by releasable connection means such as snap-in or clip means, thermal embedding, or the like.
[0033] Each of the spring arms 38 has a terminal end 40 bent radially inwards to snappingly engage the male coupling member 8 . Each terminal end 40 comprises a holding portion 42 and an insertion portion 44 which are inclined with respect to each other in V-shaped relationship. As shown in FIG. 2 , the insertion portion 44 is inclined with respect to the central axis of the snap-in coupling by an angle α which is smaller than a respective angle β of the holding portion 42 . As shown the angle α is in the order of 25°, and the angle β is in the order of 45°. It should be noted, however, that other angles may be appropriate in other applications. Due to the difference between the angles α and β closing of the snap-in coupling requires a smaller force than opening the snap-in coupling as will explained in more detail below.
[0034] As shown in FIGS. 1 and 5 the male coupling member 8 comprises a head portion 46 , a mounting portion 48 , and a drive portion 50 disposed therebetween.
[0035] Head portion 46 is provided with a radiused end surface 52 which is followed by a conical surface 54 . The conical surface 54 is followed by a substantially cylindrical surface 56 . The head portion 46 is provided with an annular groove 58 adjacent to said cylindrical surface 56 .
[0036] The annular groove 58 of the head portion 46 and the radially inwards bent terminal ends 40 of the spring arms 38 of the spring clamp 14 are of substantially mating shapes. More particularly the annular groove 58 of the head portion 56 comprises a pair of inclined conical surfaces 60 and 62 . The cone angle of the surface 62 is similar to angle α of the insertion portions 44 of the spring arms 38 , and the cone angle of the surface 60 is similar to the angle β of the holding portions 42 of the spring arms 38 . The cone angle of the conical surface 54 is also similar to the angle α of the insertion portions 44 of the spring arms 38 so that the conical surface 54 can perform a centering action upon the male coupling member 8 when the coupling is being closed as will be explained in more detail below.
[0037] The mounting portion 48 of the male coupling member 8 is formed as a threaded portion, and the drive portion 50 is of hexagonal shape for being engaged by a respective tool. As a result the male coupling member 8 may be threaded into a respective bore of the structural member 4 ; it is to be noted that the threads of the mounting portion 48 could be formed as self-cutting threads. It should be noted that the mounting portion 48 could be of any other structure and may be even an integral portion of the structural member 4 .
[0038] Operation of the snap-in coupling as described is as follows:
When the coupling members 6 and 8 have been fixedly connected to its associated structural members 2 and 4 , closing of the snap-in coupling merely requires to insert the coupling members 6 , 8 into each other by relative movement of the structural member 2 and 4 along the central axis whereby the spring clamp 14 of the female coupling member 6 and the head section 46 of the male coupling member 8 snappingly engage each other automatically.
[0040] As indicated in FIG. 2 any two diametrically opposite spring arms 38 when in a relaxed condition are spaced from each other by a predetermined minimal distance A. This distance is smaller than the minimal diameter of the annular groove 56 of the head portion 46 for a predetermined amount in order to have the spring arms 38 engage the head portion 46 under a predetermined biassing force when the snap-in coupling has been closed.
[0041] While the coupling members 6 and 8 are being inserted into each other, the insertion portions 44 of the spring arms 38 initially slide along the conical surface 54 of the head portion 46 whereby the spring arms 38 are resiliently deflected in an outward direction so as to perform a centering action between the head portion 46 and the spring clamp 14 . As soon as the insertion portions 44 of the spring arms 38 have been moved beyond the cylindrical surface 56 of the head portion 46 , the spring arms 38 “snap” radially inwards so that the radially inwards bent terminal ends 40 snappingly engage into the annular groove 58 of the head portion 46 . The terminal ends 40 which are arranged so as to form a square (see FIGS. 3 and 4 ) now uniformly contact the annular head portion 46 . In particular the holding portions 42 of the terminal ends 40 engage the conical surface 60 of the head portion 46 , and the insertion portions 44 of the terminal ends 40 engage the conical surface 62 of the head portion 46 . Due to the linear shape of the terminal ends 40 and the circular shape of the head portion 46 , line contact between these surfaces will result.
[0042] Relative insertion movements of the coupling members 6 and 8 are limited by having the arcuate end surface 52 of the head portion 46 engage the lens-shaped projection 30 of the support member 12 . A point-contact between the support member 12 of resiliently deformable plastic material and the head portion 46 allows for compensation of manufacture tolerances of the involved members. Furthermore abutment between the lens-shaped projection 30 of the support member 12 and the spherical end surface 52 of the head portion 46 provides for playless engagement between the spring clamp 14 and the head portion 46 .
[0043] Opening the snap-in coupling merely requires to move the structural members 2 and 4 away from each other in an axial direction so as to release the snap-in connection between the spring clamp 14 and the head portion 46 . Since the angle α of the insertion portions 44 of the spring arms 38 (and of the conical surface 44 of the head portion 46 ) is smaller than the angle β of the holding portions 42 (and of the conical surface 60 of the head portion 46 ), the dismounting force for opening the snap-in coupling substantially exceeds the mounting force necessary for closing the snap-in coupling. This allows to secure the snap-in coupling from being opened inadvertently without resulting in excessive mounting forces.
[0044] The resilient properties of the spring clamp 14 made of spring steel are substantially invariable within a temperature range of e.g. from −40° to 150° C. The mounting and dismounting forces of the snap-in coupling are, therefore, independent of temperature, apart from a certain temperature dependent behaviour of the plastic support member 12 . Furthermore, the values of the mounting and dismounting forces of the snap-in coupling may be precisely controlled and set by the characteristics of the used materials and the structure (geometry, material thickness, number of spring arms, etc.) of the spring clamp 14 , while the mounting and dismounting forces may be selected to differ from each other in the desired manner by respective selection of the angles α and β. Due to the support member 12 with its webs 28 being made of plastic material and due to a possibly present intermediate wall of undulated profile, the snap-in coupling has excellent vibration decoupling properties which are similar to those of the snap-in couplings in the above mentioned publications.
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A snap-in coupling for releasably connecting a first structural member and a second structural member. The snap-in coupling comprises a female coupling member comprising a plastic support member and a metallic spring clamp, said support member being insertable into a socket provided at said first structural member such that the female coupling member is retained therein, and a male coupling member comprising a mounting portion for being fixed to said second structural member, and a head portion. Said spring clamp and said head portion are arranged to snappingly engage each other when said female coupling member and said male coupling member are inserted into each other.
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PRIORITY CLAIM
This application claims priority to U.S. Provisional Patent Application Ser. No. 60/673,541, filed Apr. 21, 2005, U.S. Provisional Patent Application Ser. No. 60/673,624, filed Apr. 21, 2005 and U.S. Provisional Patent Application Ser. No. 60/673,552, filed Apr. 21, 2005.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to aircraft propulsion systems and, more specifically, a cross-flow fan propulsion system.
2. Description of the Prior Art
The cross-flow fan (CFF), developed in 1893 by Mortier, is used extensively in the HVAC industry. The fan is usually long in relation to the diameter, so the flow approximately remains 2-dimensional (2D). The CFF uses an impeller with forward curved blades, placed in a housing consisting of a rear wall and vortex wall. Unlike radial machines, the main flow moves transversely across the impeller, passing the blading twice. FIG. 1 shows a typical heating, ventilation, and air conditioning (HVAC) configuration. For an aircraft installation, the propulsor must ingest and expel the flow in a linear manner to produce forward thrust. The conventional HVAC-type CFF housing, characterized by approximately a 90 degree turn from inlet to outlet, is not well suited for this application
Inherent in all designs is a vortex region near the fan discharge, called an eccentric vortex, and a paddling region directly opposite. These regions are dissipative, and as a result, only a portion of the impeller imparts useable work on the flow. The cross-flow fan, or transverse fan, is thus a 2-stage partial admission machine. The popularity of the cross-flow fan comes from its ability to handle flow distortion and provide high pressure coefficient. Effectively a rectangular fan, the diameter readily scales to fit the available space, and the length is adjustable to meet flow rate requirements for the particular application. Since the flow both enters and exits the impeller radially, the cross-flow fan is well suited for aircraft applications. Due to the 2D nature of the flow, the fan readily integrates into a wing for use in both thrust production and boundary layer control.
In addition to increased propulsive efficiency, embedded propulsion provides reduced noise and increased safety, since the propulsor is now buried within the structure of the aircraft (e.g. no exposed propellers). Also, based on the methods in Ref. 4, by eliminating the engine pylon/nacelle support structure, the aircraft parasite drag can be reduced by up to 18 to 20%, thus improving cruise efficiency and range.
Attempts to provide a cross-flow fan in aircraft wings haven been unsuccessful. For example, some designs uses cross-flow fans embedded within the middle of a conventional airplane wing. Other designs distribute fully embedded cross-flow fans near the trailing edge of a conventional transport aircraft, with shafts and couplings connecting them to wing-tip and root-mounted gas turbines. Air is ducted into the fan from both wing surfaces, and expelled out at the trailing edge. These designs, however, limits the fan size and ducting. Also, the CFF may not be a viable option for high-speed applications due to compressibility effects (i.e. choking). These configurations fall short of expectations due to poor fan placement and poor housing design. These deficiencies result in low fan performance, reduced circulation control, and low thrust production.
SUMMARY OF THE INVENTION
It is therefore a principal object and advantage of the present invention to provide a distributed cross-flow fan wing design that provides high propulsive efficiency.
It is a further object and advantage of the present invention to provide a distributed cross-flow fan wing design that provides low parasite drag.
It is an additional object and advantage of the present invention to provide a distributed cross-flow fan wing design that provides reduced flow separation at high angle of attack.
In accordance with the foregoing objects and advantages, in one application, the present invention provides a cross-flow propulsion mechanism for use in providing propulsion to an aircraft, that includes a housing defining an inlet, a rotor compartment, and an outlet, with the inlet adapted to receive an inflow of air along a first longitudinal axis; a rotor mounted within the rotor compartment and adapted to receive the airflow introduced into said housing through the inlet and rotate about a second longitudinal axis that is substantially perpendicular to the first longitudinal axis; and an outlet adapted to receive the airflow processed through the rotor and exhaust air along a third longitudinal axis that is substantially parallel to the first longitudinal axis.
In a second application of the invention, it provides an aircraft including an aircraft body shaped in the form of an airfoil having leading and trailing edges; and a cross-flow propulsion mechanism for use in providing propulsion to an aircraft, that includes a housing defining an inlet, a rotor compartment, and an outlet, with the inlet adapted to receive an inflow of air along a first longitudinal axis; a rotor mounted within the rotor compartment and adapted to receive the airflow introduced into said housing through the inlet and rotate about a second longitudinal axis that is substantially perpendicular to the first longitudinal axis; and an outlet adapted to receive the airflow processed through the rotor and exhaust air along a third longitudinal axis that is substantially parallel to the first longitudinal axis.
In a third application of the present invention, it provides a vehicle convertible between land travel and air travel, that includes a vehicle body shaped in the form of an airfoil having leading and trailing edges; and a cross-flow propulsion mechanism for use in providing propulsion to an aircraft, that includes a housing defining an inlet, a rotor compartment, and an outlet, with the inlet adapted to receive an inflow of air along a first longitudinal axis; a rotor mounted within the rotor compartment and adapted to receive the airflow introduced into said housing through the inlet and rotate about a second longitudinal axis that is substantially perpendicular to the first longitudinal axis; and an outlet adapted to receive the airflow processed through the rotor and exhaust air along a third longitudinal axis that is substantially parallel to the first longitudinal axis.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
FIG. 1 is a diagram of a prior art cross-flow fan.
FIG. 2 is a diagram of a baseline inline housing according to the present invention.
FIG. 3 is a diagram of a cross-flow fan airfoil geometry according to the present invention.
FIG. 4 is a diagram of the grid according to the present invention near the fan blades.
FIG. 5 is a chart of computed inline housing performance according to the present invention.
FIG. 6 is a diagram of time-averaged streamlines at 10 degrees angle of attack according to the present invention.
FIG. 7 is a diagram of total pressure ratios at 10 degrees angle of attack according to the present invention.
FIG. 8 is a chart of total pressure wake profiles according to the present invention.
FIG. 9 is a diagram of time-averaged streamlines at 40 degrees angle of attack according to the present invention.
FIG. 10 is a diagram of system analysis with wake ingestion according to the present invention.
FIG. 11 is a diagram of a modified airfoil according to the present invention.
FIG. 12 is a chart of cross-flow fan performance according to the present invention.
FIG. 13 is a chart of the effect of boundary layer ingestion according to the present invention.
FIG. 14 is a chart of the effect of boundary layer ingestion according to the present invention.
FIG. 15 is a chart of airfoil performance according to the present invention.
FIG. 16 is a series of charts comparing system analysis according to the present invention.
FIG. 17 is a perspective view of an aircraft according to the present invention.
FIG. 18 is another perspective view of an aircraft according to the present invention.
FIG. 19 is a perspective view of a further embodiment of an aircraft according to the present invention.
FIG. 20 is a perspective view of an additional embodiment of an aircraft according to the present invention.
FIG. 21 is a perspective view of another embodiment of an aircraft according to the present invention.
FIG. 22 is a perspective view of a convertible automobile/aircraft in the automobile configuration according to the present invention.
FIG. 23 is a perspective view of a convertible automobile/aircraft in the aircraft configuration according to the present invention.
FIG. 24 is a schematic of another embodiment of an aircraft according to the present invention.
DETAILED DESCRIPTION
Glossary:
A=area
C D =airfoil drag coefficient, D/(0.5 ρU ∞ 2 C )
C L =airfoil lift coefficient, L/(0.5 ρU ∞ 2 C )
C P =power coefficient, Power/(ρU ∞ 3 D f )
C T =thrust coefficient, T/(0.5 ρU ∞ 2 D f )
CS=control surface
D=drag per unit span
D BL =drag due to boundary layer build-up
D f =cross-flow fan diameter
F x =x-component of force
H=arbitrarily large distance
h i =propulsor inlet height
h j =propulsor outlet height
h w =ingested wake height
{tilde over (h)}=non-dimensionalized ingested wake height
L=lift per unit span
{dot over (m)}=mass flow rate
p=variable
P P =propulsive power
P T =total pressure
P T i =total pressure at propulsor inlet
P T i =mass-weighted total pressure at propulsor inlet
Q=flow rate per unit span
r=radial distance
T=propulsor thrust
U=velocity
U f =fan tip speed
Ũ j =non-dimensionalized jet velocity, U j /U ∞
U W =propulsor inlet velocity with wake ingestion
U ∞ =velocity in freestream
x=x-coordinate
y=y-coordinate
Δ=change in value
φ=flow coefficient, Q/(D f U f )
η p propulsive efficiency
η t =total efficiency, (QΔP T )/(Ωτ)
μ=advance ratio, U ∞ /U f
μ v =absolute viscosity
ρ=density
Ψ t =total pressure coefficient, ΔP T /(0.5 ρU f 2 )
τ=fan torque
Ω=fan speed, rad/s
Subscripts and Superscripts
in=into control volume
j=in jet
′=non-wake ingestion
Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in FIGS. 2 and 3 , a cross-flow fan (CFF) propulsion system designated generally by reference numeral 10 generally comprises a housing 11 that defines an inlet 12 into which air flows along a first longitudinal axis A-A, a rotor compartment 14 in which a rotor 16 is mounted for rotational movement about a second longitudinal axis B-B that is substantially perpendicular to axis A-A, and an outlet 18 from which air is exhausted along a third longitudinal axis C-C that is substantially parallel to and vertically spaced below axis A-A. A movable deflector 20 may be attached to the housing 11 to alter the flow direction of the inlet 12 and outlet 18 .
With reference to FIGS. 17-21 , a personal aircraft 100 that incorporates CFF 10 therein is illustrated. Aircraft 100 includes a body 102 that shaped in the form of an airfoil and that extends along a longitudinal axis D-D. CFF 10 is mounted transversely across body 102 (i.e., the trailing edge of the airfoil), such that axis B-B is transverse to axis D-D. Preferably, CFF 10 is mounted above body 102 such that the airflow passing over body 102 is effectively captured by inlet 12 , while not being impacted by other vortices created by body 102 , as explained in greater detail hereinafter. CFF 10 is preferably of a width that approximates the width of the body 102 . Deflector 20 may be used, preferably via computer control as is in known to those skilled in the art, to change the direction of the exhausted airflow to enhance lift or drag as desired for take-off or landing. Streamed exit ducting allows for easily controlled vectored thrust. The middle section of aircraft 100 contains ample space for passenger seating or cargo.
With reference to FIGS. 22-23 , a vehicle 200 that is convertible between a land based vehicle (i.e., car) and aircraft and that incorporates CFF 10 is illustrated. Vehicle 200 includes an airfoil shaped body 202 at the trailing edge of which CFF 10 is mounted. Wings 204 and 206 may be detachably mounted to opposing sides of body 202 to enhance lift characteristics of the vehicle, as can stability elements 208 , such as canards, elevators, and the like. As with the other applications, CFF is preferably of a width that approximates the width of the body.
Vehicle 200 may dimensioned to meet the maximum width allowed over conventional roads and highways. Vehicle 200 includes an airfoil shaped exterior preferably with a 34 percent thickness-to-chord ration. In addition, vehicle 200 has removable or retractable access to CFF 10 . Vehicle may be converted with the addition or removal of stability element 208 , such as rotating canards, on either side of a body 202 , and detachable wings 204 , 206 having conventional circulation control airfoil shapes for both lift enhancement (increasing wing aspect ratio) and flight control (e.g., ailerons, elevators, tail). Flight control may also be enhanced with vectored thrust from deflector 20 of CFF 10 . The detachable wings may be taken off and stored when not in use.
Despite relatively low fan efficiency, the present invention is competitive with conventional propulsion technologies. The raised inlet eliminates the fan size restriction caused by fully embedding the fan within the airfoil. Also, cross-flow fan performance is quite insensitive to even large amounts of wake ingestion, making it ideal for this type of configuration. In fact, the fan of the present invention is capable of drawing in the boundary layer, regardless of its thickness.
Referring to the 34 percent thick airfoil seen in FIG. 3 , even at low angle of attack, the wake can be quite large, producing large pressure drag. This renders very thick wing sections impractical for most aircraft applications as the drag penalty outweighs any benefits gained in lift or interior volume. Without the suction effect of a rear-mounted CFF, the flow separates given only a small angle of attack. The embedded cross-flow fans near the trailing edge eliminate flow separation by drawing the flow back toward the surface and into the fan ducting, yielding very high lift coefficients. This is turn results in short takeoff and landing (STOL) capability and low in-flight aircraft stall speed without the use of additional high lift devices, such as slotted flaps and leading edge slats. The combination of circulation control and differential thrust, accomplished through fan speed and inlet height regulation, may eliminate the need for control surfaces. By vectoring the thrust via a jet flap, additional lifting force and control are also possible. Additionally, the low fan efficiency will be off-set by lower drag (e.g. engine nacelle, pylon, and interference drag not present).
CFD Simulations
CFD simulations of the cross-flow fan airfoil were performed using a 2D double-precision segregated solver. Second-order discretization of the convective terms was used throughout all calculations, and the SIMPLE algorithm provided pressure-velocity coupling. The standard k-εturbulence model was used with the enhanced wall treatment option, which combines a two-layer model with enhanced wall functions for greater robustness in near-wall grid generation (i.e. relaxed requirements on wall y 30 values). In order to simulate the fan rotating, the area surrounding the blades was designated as a sliding mesh region.
Unsteady simulations require proper setting of both the time step size and the convergence criteria within each time step. For cross-flow fan simulations, a time step size equal to 1/20 th the blade passing period (e.g. 720 time steps per revolution for a 36-bladed fan) captured the unsteady flow quite well. Within each time step, iterations were performed until the solution no longer changed. It was found necessary to reduce all residuals (continuity, momentum, and turbulence quantities) to at least 10 −5 , although for most cases, the residuals were reduced several orders of magnitude less (usually 10 −7 to 10 −10 ). All results are time-averaged data over one fan revolution. Dual-CPU Pentium 4 PCs, as well as multiple nodes of a 30-node Beowulf cluster, were used, with the computational time ranging from two days for the housing alone up to about two weeks for the full cross-flow fan airfoil.
Baseline Inline Housing
The baseline inline housing shown in FIG. 2 is divided into three regions: the flow through the duct, the fan bladed region, and the fan interior. The fan bladed region rotated at a specified rpm, while the other two regions remained stationary. A close-up of the grid surrounding the blades is shown in FIG. 4 . Quadrilateral mesh was used near the blade surfaces and along the casing walls, and triangular mesh filled in the remainder of the domain. The combination gave a smooth transition from the blade and wall surfaces to the sliding interfaces. Since no experimental data exists for the current configuration, validation of the CFD model was performed using published results for other housings, and will be presented in a future paper.
For the simulation, a 0.3 m diameter 36-blade fan was selected. The blades consisted of simple circular arcs with rounded leading and trailing edges. The inlet and outlet heights were 0.3 m and 0.176 m, respectively. The density and viscosity were set to standard sea level conditions:ρ=1.225 kg/m 3 and μ v =1.7894×10 −5 kg/(m-s). At the inlet, uniform ambient total pressure was specified with a turbulence intensity of 1% and hydraulic diameter of 0.3 m. A uniform static pressure boundary condition was specified at the outlet. Changes in mass flow rate, and hence flow coefficient, were achieved by adjusting the back-pressure. The data presented corresponds to a fixed fan speed of 2,000 rpm and a time step size of 4.17×10 −5 s.
A grid dependency study was performed, with the final mesh consisting of 81,000 cells. The calculated fan performance for this case is shown in FIG.5 . The figure also shows the results for a coarser grid with only 43,000 cells. The graph shows that using half the grid cells produces only a small change in the results. A common feature of cross-flow fans, it is interesting to note that the operating point corresponding to maximum total pressure coefficient does not coincide with that for maximum total efficiency. For the fine mesh, the maximum total pressure coefficient is 4.03 at φ=1.1; the total efficiency reaches a maximum value of 67% at φ=0.5.
Cross-Flow Fan Airfoil
Simulation of the cross-flow fan airfoil takes considerably more time than for the housing alone. The time to reach steady-state is based on the flow time from inlet to outlet. As the domain is small, for the baseline housing this occurs after only a few thousand time steps. In contrast, for the CFF-Airfoil simulations, the steady-state is not reached for many times that number, since the computational domain measures 20 c×20 c, where c is the airfoil chord length. As an example, with the airfoil at zero degree angle of attack and the fan speed set to 1,000 rpm, the unsteady calculations took about 24,000 time steps, or about 2 seconds of flow time, to reach the steady-state. The drastic increase in computation time stems from the fact that in the latter case enough time must elapsed for the error in the initial solution to convect downstream and out of the domain. The same is true for the housing alone; however, the domain is significantly smaller, allowing the error to propagate out much faster.
The airfoil geometry is seen in FIG. 3 . An airfoil chord length of 15 ft was selected, and the corresponding cross-flow fan diameter was 2.1 ft. At the inlet, uniform velocity was specified in the positive x-direction with a turbulence intensity of 1% and turbulence viscosity ratio of 5%. At the outlet, a uniform static pressure boundary condition was used. Symmetry boundaries were specified for the top and bottom of the domain.
Mesh generation was similar to the inline housing case. Quadrilateral mesh covered the blade surfaces and exterior airfoil geometry, and triangular mesh filled in between. Two interfaces were again used: one just outside of the fan blades, and one just inside. To demonstrate solution dependency to mesh changes, the present invention was simulated at zero degree angle of attack at an altitude of 8,000 ft: ρ=0.001868 slug/ft 3 and μ v =3.5753×10 −7 lbf-s/ft 2 . The freestream velocity was set to 206 ft/s, and the fan speed to 1,000 rpm. The corresponding time step size used was 8.33×10 31 5 s. The starting solution for the unsteady case was obtained by first performing a steady calculation with the fan modeled as a moving reference frame zone. In doing this, the fan region does not rotate; however, the no-slip boundary condition on the fan blades is still enforced in the relative frame (i.e. the local blade velocity is equal to Ωr). This produces a total pressure rise through the fan with magnitude comparable to the unsteady calculation, and consequently provides a good initial solution for the external aerodynamics.
The grid dependency study presented consists of three grids of increasing resolution: 64,000 cells, 88,000 cells, and 131,000 cells. The average fan blade y + values for the coarse, medium, and fine grids were 63, 46, and 22, respectively. Table 1 gives the final computed results for each grid, along with the percent difference between the fine and the two coarser grids. In the current configuration, the jet leaves the fan with a large amount of swirl, causing the flow to deflect upwards, and resulting in a net downward force on the airfoil (i.e. negative lift coefficient). The results show only a small difference between the medium and fine grids, justifying use of the fine grid for the remainder of the CFF-Airfoil simulations.
TABLE 1
Grid comparison at 1,000 rpm
Coarse Grid
Medium Grid
Fine
% Difference
% Difference
Grid
Parameter
Value
from Fine Grid
Value
from Fine Grid
Value
φ
0.933
1.7
0.909
−1.0
0.918
Ψ t
4.260
5.8
4.032
0.1
4.026
η t
0.547
−1.6
0.555
0.0
0.555
C L
−0.561
−10.7
−0.604
−3.9
−0.628
The present invention was next simulated at 10 degrees angle of attack at 200 ft/s and standard sea level conditions. The fan speed was again set at 1,000 rpm; the time step size remained at 8.33×10 −5 s. The grid was generated by rotating the airfoil clockwise and reconstructing the grid as done previously. The jet deflector was aligned horizontally to force the flow to leave the CFF ducting in the freestream direction.
FIG. 6 illustrates the streamlines for this test. With the fan off, the flow effectively bypasses the fan ducting, producing a large wake behind the airfoil. With the fan on, however, the wake size reduces dramatically. Total pressure contours with the fan on are seen in FIG. 7 , and present a clear picture of where energy is gained and lost. The values in FIG. 7 are presented as total pressure ratio, defined as the local total pressure divided by the freestream value. The large values for total pressure ratio in the exhaust correspond to the thrust producing high momentum jet flow, whereas values less than 1.0 represent energy loss. In FIG. 7 , the boundary layer growth over the suction surface is apparent. An important feature of the cross-flow fan is its ability to operate well even when the inlet profile is non-uniform due to ingestion of low momentum boundary layer flow. Also visible in FIG. 7 is the eccentric vortex, the region of very low total pressure located within the fan.
FIG. 8 depicts the wake profiles for the 1,000 rpm case, for the fan turned off, and for the original airfoil at 10 degrees angle of attack. The data are shown along a line 20% chord behind the airfoil. With the fan turned off, the wake profile is very similar to that for the original airfoil alone, only shifted in the vertical direction due to the change in the trailing edge geometry. The large total pressure deficit indicates a substantial wake immediately behind the airfoil. With the fan turned on, the total pressure profile outside the jet matches the freestream almost exactly. The jet produces a total pressure increase in the wake region, and entrains the flow near the airfoil trailing edge, virtually eliminating boundary layer separation. Additionally, the jet provides excess thrust, which is necessary in practice, since 3-dimensional effects will be present, while at the same time, complete span-wise distribution of the cross-flow fan system will probably not be possible.
As explained above, the cross-flow fan airfoil is ideal for high-lift STOL applications. To demonstrate this, the airfoil was next placed at 40 degrees angle of attack, with a freestream velocity of 50 ft/s at standard sea level conditions. Additionally, to demonstrate the mechanism for vectored thrust, the exit ducting was deflected 30 degrees downward.
FIG. 9( a ) shows the streamlines with the fan off. As expected, a large area of separated flow results. The airfoil here is fully stalled, with a calculated lift coefficient of 1.054. This is in stark contract to the case with the fan turned on. The time-averaged streamlines at 1,250 rpm are plotted in FIG. 9( b ), and show that the flow remains fully attached. With the fan on there is a strong suction effect, which draws the flow into the fan housing, prohibiting separation. The computed lift coefficient is 6.408 for this test of the present invention. Assuming the engine has enough power, the rpm can always be increased to provide a stronger suction effect, effectively creating a stall-free airfoil. The effect will only be limited by the mass-flow rate (i.e. fan choking). It is unlikely, however, that choking will be a problem, since the high-lift configuration would only be used at takeoff and landing, where the freestream Mach number is low, and for low-speed maneuvers.
Table 2 provides a summary of the numerical results for the simulations of the present invention at 10 and 40 degrees angle of attack. The negative values for drag coefficient indicate a net thrust. Horsepower was computed using the time-averaged torque on the cross-flow fan blades.
TABLE 2
Summary of numerical results
HP per
foot
Angle of Attack, degrees
C L
C D
φ
Ψ t
η t
of span
10, Fan off
0.423
0.035
10, Fan on - 1,000 rpm
0.543
−0.056
0.943
4.544
0.550
46.964
40, Fan off
1.054
0.225
40, Fan on - 1,250 rpm
6.408
−0.987
0.506
2.337
0.601
23.167
To adequately implement the present invention, several important features must be included. As already demonstrated by the preceding CFD results, the propulsion system ingests a large amount of boundary layer, or wake, flow from the airfoil suction surface. Inlet momentum deficit does not strongly affect CFF performance; however, it does play a major role at the system level. In the current design, the flow exits the propulsor at the trailing edge as a jet, and fills up the wake behind the airfoil. As mentioned previously, this too has a positive effect, and hence must be included in the model. Finally, and probably most importantly, the cross-flow fan itself must be modeled.
The proceeding analysis is based on the model given in FIG. 10 . The inlet velocity profile is given by U W , and the inlet height by h i . The flow accelerates through the propulsor, and leaves with velocity U j . Ambient static pressure is assumed at both the inlet and outlet. For low-speed applications, this is usually a good approximation at the outlet, but will not be correct at the inlet, since the pressure is inherently different due to airfoil curvature (i.e. potential field effects). In the design process, one needs to consider this when sizing the inlet. Likewise, when making comparisons with experimental or CFD results, the inlet velocity must be converted to an equivalent profile corresponding to the same total pressure, but at ambient static pressure.
Using conservation of mass and conservation of momentum in the x-direction, given in Eqs. (1) and (2), respectively, propulsor thrust and inlet momentum deficit, termed here boundary layer drag, are determined.
∫
CS
U
⇀
·
ⅆ
A
⇀
=
0
(
1
)
F
x
=
ρ
∫
CS
U
x
(
U
⇀
·
ⅆ
A
⇀
)
(
2
)
For the present model, a constant jet velocity was assumed (U j =Constant). At the inlet, a power-law relation was used, since when compared to the CFD results, this was found to give a good approximation to the mass-flow rate with wake ingestion. The inlet profile is given in Eq. (3), where p is yet to be determined.
U
w
=
{
U
∞
(
y
/
h
w
)
p
for
0
≤
y
≤
h
w
U
∞
for
h
w
<
y
≤
h
i
(
3
)
Inserting Eq. (3) into Eqs. (1) and (2) and performing the integration
D
BL
=
ρ
U
∞
2
h
w
[
1
p
+
1
-
1
2
p
+
1
]
(
4
)
T
=
ρ
U
∞
(
U
j
-
U
∞
)
[
h
w
p
+
1
+
(
h
i
-
h
w
)
]
+
ρ
U
∞
2
h
w
[
1
p
+
1
-
1
2
p
+
1
]
(
5
)
Dividing Eq. (4) by Eq. (5) gives the ratio of ingested boundary layer drag to thrust. This quantity ranges from zero, corresponding to no wake ingestion (or infinitely large thrust), to one (exhaust velocity equal to freestream velocity), and is a convenient means for comparing different designs. In Eq. (6) {tilde over (h)} is the ratio of the ingested wake height to the inlet height, and also ranges from zero to one. It is important to note that a small value for {tilde over (h)} may correspond to either minimal wake ingestion (for a fixed inlet height) or a large inlet height (for a fixed wake ingestion).
D BL T = 1 ( U ~ j - 1 ) ( 1 h ~ + 1 p + 1 - 1 ) 1 p + 1 - 1 2 p + 1 + 1 ( 6 )
Where
{tilde over (h)}=h w /h i (7)
The cross-flow fan is modeled by bringing in the fan performance map. This is accomplished by using either CFD or experimental data for a particular design, or by using a “nominal” performance map, corresponding to configurations very similar to the present application. This is possible, since it was found that alterations in the baseline inline housing geometry for installation purposes produce only minor changes in the fan performance.
In order to bridge the gap between the exterior analysis and the fan performance curves, it is necessary to match the total pressure rise through the propulsor. Here, the mass-weighted total pressure is used at the inlet
P
T
i
_
=
∫
0
h
i
P
T
i
(
y
)
ⅆ
m
.
∫
0
h
i
ⅆ
m
.
(
8
)
Of particular interest are the quantities relating propulsor thrust to the kinetic energy input to the flow and the power input to the fan. The first is called propulsive efficiency, and is defined in Eq. (9).
η P = TU ∞ P P ( 9 ) P p = 1 2 ρ ∫ 0 h j U j 3 ⅆ y - 1 2 ρ ∫ 0 h i U w 3 ⅆ y ( 10 )
Where
Substituting Eqs. (5) and (10) into Eq. (9)
η
p
=
2
(
U
~
j
-
1
)
[
h
~
p
+
1
+
(
1
-
h
~
)
]
+
2
h
~
[
1
p
+
1
-
1
2
p
+
1
]
(
1
-
h
~
)
(
U
~
j
2
-
1
)
+
U
~
j
2
h
~
p
+
1
-
h
~
3
p
+
1
(
11
)
Non-dimensionalizing thrust and power, the second relation, given by Eq. (12), represents the amount of thrust produced per unit power. By maximizing this quantity, for a given thrust, the necessary power input will be minimized.
C
T
C
P
=
4
η
t
μ
2
Ψ
t
[
(
U
~
j
-
1
)
+
h
~
p
+
1
-
h
~
2
p
+
1
1
-
h
~
+
h
~
p
+
1
]
(
12
)
Where μ is the advance ratio, and is related to the flow coefficient through the relation
ϕ
=
μ
h
i
D
f
[
1
-
h
~
+
h
~
p
+
1
]
(
13
)
The system analysis formulation thus involves evaluating the effect of the 3 independent parameters μ, {tilde over (h)}{tilde over ( )}, and h i /D f ,on the overall measures of system performance: D BL /T, C t /C p , and η p .
In order to proceed further, it ist necessary to determine the value of the exponent ‘p’ in the preceding analysis. In addition, comparison runs were needed. CFD simulations of the baseline inline housing and the present invention were used for these tasks. For the present invention, two different geometries were run. The first corresponded to FIG. 3 , where the chord length was 15 ft and the cross-flow fan diameter 2.1 ft. Calculations were performed for seven different rpm settings at zero degree angle of attack with fan speeds ranging from 500 rpm to 1,250 rpm. The second set of runs corresponded to approximately the same exterior airfoil shape, but with a 1.0 ft diameter fan included. This modified geometry is shown in FIG. 11 .
A compilation of the fan performance data for all three cases is depicted in FIG. 12 . It is important to note that the non-dimensional quantities Ψ t and η t are not strong functions of inlet/outlet ducting geometry. This is fortunate from the standpoint of system analysis comparisons, since it allows a single curve to represent the fan performance for all cases. The solid and dashed lines plotted in FIG. 12 are polynomial curve-fits for total pressure coefficient and total efficiency, and are given by eqs. (14) and (15), respectively. From the CFF-Airfoil simulations, it was found that p=0.28 gave the best match for mass flow rate across all cases, with an average error of less than 0.3%.
Ψ t =−5.3731φ 4 +11.166φ 3 −8.3403φ 2 +6.5663φ+0.4212 (14)
η t =0.2898φ 3 −1.3829φ 2 +1.3682φ+0.2479 (15)
The present invention includes boundary layer ingestion into the fan, whereas in the conventional propulsion model, the propulsor ingests only uniform freestream flow. From Ref. 2, the thrust, propulsive power, and propulsive efficiency for the latter case are
T
′
=
m
.
j
′
(
U
j
′
-
U
∞
)
(
16
)
P
p
′
=
1
2
m
.
j
′
(
U
j
′2
-
U
∞
2
)
(
17
)
η
p
′
=
2
U
~
j
′
+
1
(
18
)
For comparison, two propulsors with equal thrust and mass flow rate will be used: one with and one without boundary layer ingestion. Dividing Eq. (10) by Eq. (17) yields the propulsive power ratio, which represents the energy savings relative to the conventional non-wake ingestion case.
P p P p ′ = ( 1 - h ~ ) ( U ~ j 2 - 1 ) + U ~ j 2 h ~ p + 1 - h ~ 3 p + 1 ( U ~ j ′2 - 1 ) [ h ~ p + 1 + ( 1 - h ~ ) ] ( 19 )
Where
U
~
j
′
=
U
~
j
+
[
1
p
+
1
-
1
2
p
+
1
1
p
+
1
+
1
h
~
-
1
]
(
20
)
Propulsive power ratio and propulsive efficiency are plotted in FIGS. 13 and 14 versus D BL /T for h i /D f= 0.5. In the figures, small values of D BL /T correspond to large thrust production, whereas D BL /T =1 corresponds to a perfect filling-in of the wake behind the airfoil (i.e. the ideal cruising condition). As D BL /T and {tilde over (h)} increase, propulsive power ratio decreases. The greatest power savings is thus achieved when D BL /T=1 and {tilde over (h)}=1 (i.e. boundary layer ingestion is large). Propulsive efficiency also increases with increasing D BL /T, and is always greater with boundary layer ingestion. Propulsive efficiency can actually exceed 100% as D BL /T approaches unity 2. It is interesting to note, however, that as {tilde over (h)}increases, η p actually decreases. For small values of D BL /T, the effect becomes quite significant, and implies that for a specified boundary layer ingestion and propulsor thrust, from a propulsive efficiency standpoint, it is desirable to have a large inlet opening. The implication of these results is that, although small propulsors benefit greatly from boundary layer ingestion, larger ones may still results in better performance. Thus a design tradeoff exists where using a larger fan results in higher propulsive efficiency, but with an added weight penalty and greater drag due to an increase in surface area.
The question is now if {tilde over (h)} is fixed, for example at 0.5, is it beneficial to operate at a high or low value of h i /D f ? This situation is plotted in FIG. 15 , which shows that the answer depends on the particular design and operating point. For a fixed value of {tilde over (h)}, a lower h i /D f always gives a higher possible value for C T /C P . The analysis shows that for a fixed inlet height (i.e. fixed h i ), the best choice for fan diameter depends on the value of D BL /T; for a given D BL /T, the fan and housing should be chosen such that operation lies on the maximum C T /C P line. For a given wake height, this translates into a direct relation between the necessary thrust and fan diameter for minimum power. Also note, as can be seen in the equations, propulsive efficiency is not a function of h i /D f .
In order to validate the system analysis formulation, comparisons were made with the CFF-Airfoil CFD results. The graphs of C T /C p and η p versus D BL /T for both the small and large fan cases are shown in FIG. 16 . Excellent agreement is seen between the system analysis predictions and CFD data for propulsive efficiency. For C T /C p the system analysis also performs well, especially for the larger fan. It is important to note that the comparison depends heavily on an accurate approximation of the wake height {tilde over (h)}. This should come as no surprise, since it was already seen that large amounts of propulsor wake ingestion create notable differences in overall system performance.
As noted previously, it is necessary to compare the analysis with CFD results where the inlet velocity profile is converted to an equivalent one, but at ambient static pressure. In doing this, one also must assume an isentropic contraction or expansion of the flow, depending on whether the pressure is above or below the ambient value. Thus not only is an equivalent velocity profile determined, but also an equivalent inlet height. What is remarkable is the level of agreement between the analytical and the CFD results, given that the system analysis curves correspond to the actual ratio of inlet height to fan diameter (i.e. the physical value of h i /D f ). If the exact profile for pressure is known at the outset, then even better correlation can be expected. The implication here is that for preliminary design, where the process is reversed, the system analysis will provide a good approximation of the expected performance for a large range of designs, given only a small number of input parameters.
The present invention thus comprises a successful application of wing-embedded, distributed cross-flow fan propulsion. The inline housing design of the present invention smoothly integrates within the airfoil to produce a high total pressure rise and thrust. Additionally, the embedded propulsion system of the present invention reduces the wake size for both low and high angle of attack. Boundary layer reduction and vectored thrust capability provide for very high lift coefficients. By creating an integrated fan/airfoil system according to the present invention, the interference effects caused by external propulsors and their support structures may be eliminated, increasing overall performance. The high propulsive efficiency and low drag in cruise of the present invention provides for increased range over conventional designs. The present invention also readily allows for the mounting of multiple fans along the span of the aircraft. This redundancy improves safety dramatically in the case of fan failure. In addition, the entire housing can be made to lift directly out of the wing for easy maintenance and replacement.
The distribution in the present invention of cross-flow fan airfoil sections along the entire span lends itself directly to flying wing or blended-wing-body (BWB) type aircraft. Additionally, by coupling the cross-flow fans with individual fuel cell powered electric motors, the need for shafts connecting the fans is eliminated. Such an aircraft provides a platform for a future BWB-CFF aircraft: low emission, low noise, redundant power source, highly efficient in cruise, highly maneuverable, and with excellent STOL capabilities. In the center region of the aircraft, the cross-flow fans produce the thrust, with the thick airfoil sections providing ample room for passengers (e.g. a 34% thick airfoil with a 15 ft chord length has a maximum thickness of over 5 feet). Outboard airfoil sections will most likely be thinner, but could still contain cross-flow fans for added thrust, wake reduction, and control via differential thrust (for yaw control) and differential lift through circulation control and vectored thrust (for pitch control).
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A cross-flow propulsion mechanism for use in providing propulsion to an aircraft, includes a housing defining an inlet, a rotor compartment, and an outlet. The inlet is adapted to receive an inflow of air along a first longitudinal axis. The rotor is mounted within the rotor compartment and adapted to receive the airflow introduced into the housing through the inlet and rotate about a second longitudinal axis that is substantially perpendicular to the first longitudinal axis. The outlet is adapted to receive the airflow processed through the rotor and exhaust air along a third longitudinal axis that is substantially parallel to the first longitudinal axis. The propulsion mechanism can be applied in a personal aircraft, an STOL aircraft, and a hybrid automobile and aircraft.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/852,547, filed May 24, 2004, now U.S. Pat. No. 6,991,740, issued Jan. 31, 2006, which is a continuation of application Ser. No. 10/160,528, filed May 31, 2002, now U.S. Pat. No. 6,814,834, issued Nov. 9, 2004, which is a continuation of application Ser. No. 09/478,692, filed Jan. 6, 2000, now U.S. Pat. No. 6,398,905, issued Jun. 4, 2002, which is a continuation of application Ser. No. 09/124,329, filed Jul. 29, 1998, now U.S. Pat. No. 6,036,586, issued Mar. 14, 2000.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to polishing methods and apparatus. More particularly, the invention pertains to apparatus and methods for polishing and planarizing semiconductor wafers, optical lenses and the like.
2. State of the Art
In the manufacture of semiconductor devices, it is important that the surface of a semiconductor wafer be planar.
For high density semiconductor devices having features with extremely small sizes, i.e., less than 1 μm, planarity of the semiconductor wafer is particularly critical to the photolithographic forming of the extremely small conductive traces and the like.
Methods currently used for planarization include (a) reflow planarization, (b) application of a sacrificial dielectric followed by etch back planarization, (c) mechanical polishing and (d) chemical-mechanical polishing (CMP). Methods (a) through (c) have some applications but have disadvantages for global wafer planarization, particularly when fabricating dense, high speed devices.
In U.S. Pat. No. 5,434,107 to Paranjpe, a planarization method consists of applying an interlevel film of dielectric material to a wafer—and subjecting the wafer to heat and pressure so that the film flows and fills depressions in the wafer, producing a planar wafer surface. An ultraflat member overlying the dielectric material ensures that the latter forms a flat surface as it hardens. The ultraflat member has a non-stick surface such as polytetrafluoroethylene so that the interlevel film does not adhere thereto.
In a similar method shown in European Patent Publication No. 0 683 511 A2 to Prybyla et al. (AT&T Corp.), a wafer is covered with a hardenable low-viscosity polymer and an object with a highly planar surface is placed in contact with the polymer until the polymer is cured. The object is separated from the polymer, which has cured into a highly planar surface.
The planarization method of choice for fabrication of dense integrated circuits is typically chemical-mechanical polishing (CMP). This process comprises the abrasive polishing of the semiconductor wafer surface in the presence of a liquid or slurry.
In one form of CMP, a slurry of an abrasive material, usually combined with a chemical etchant at an acidic or alkaline pH, polishes the wafer surface in moving compressed planar contact with a relatively soft polishing pad or fabric. The combination of chemical and mechanical removal of material during polishing results in superior planarization of the polished surface. In this process it is important to remove sufficient material to provide a smooth surface, without removing an excessive quantity of underlying materials such as metal leads. It is also important to avoid the uneven removal of materials having different resistances to chemical etching and abrasion.
In an alternative CMP method, the polishing pad itself includes an abrasive material, and the added “slurry” may contain little or no abrasive material, but is chemically composed to provide the desired etching of the surface. This method is disclosed in U.S. Pat. No. 5,624,303 to Robinson, for example.
Various methods for improving wafer planarity are directed toward the application of interlayer materials of various hardness on the wafer surface prior to polishing. Such methods are illustrated in U.S. Pat. No. 5,618,381 to Doan et al., U.S. Pat. No. 5,639,697 to Weling et al., U.S. Pat. No. 5,302,233 to Kim et al., U.S. Pat. No. 5,643,837 to Hayashi, and U.S. Pat. No. 5,314,843 to Yu et al.
The typical apparatus for CMP polishing of a wafer comprises a frame or base on which a rotatable polishing pad holder or platen is mounted. The platen, for example, may be about 20-48 inches (about 50-122 cm.) or more in diameter. A polishing pad is typically joined to the platen surface with a pressure-sensitive adhesive (PSA).
One or more rotatable substrate carriers are configured to compress, e.g., semiconductor wafers against the polishing pad. The substrate carrier may include non-stick portions to ensure that the substrate, e.g., wafer, is released after the polishing step. Such is shown in U.S. Pat. No. 5,434,107 to Paranjpe and U.S. Pat. No. 5,533,924 to Stroupe et al.
The relative motion, whether circular, orbital or vibratory, of the polishing pad and substrate in an abrasive/etching slurry may provide a high degree of planarity without scratching or gouging of the substrate surface, depending upon wafer surface conditions. Variations in CMP apparatus are shown in U.S. Pat. No. 5,232,875 to Tuttle et al., U.S. Pat. No. 5,575,707 to Talieh et al., U.S. Pat. No. 5,624,299 to Shendon, U.S. Pat. No. 5,624,300 to Kishii et al., U.S. Pat. No. 5,643,046 to Katakabe et al., U.S. Pat. No. 5,643,050 to Chen, and U.S. Pat. No. 5,643,406 to Shimomura et al.
In U.S. Pat. No. 5,575,707 to Talieh et al., a wafer polishing system has a plurality of small polishing pads which together are used to polish a semiconductor wafer.
As shown in U.S. Pat. No. 5,624,304 to Pasch et al., the polishing pad may be formed in several layers, and a circumferential lip may be used to retain a desired depth of slurry on the polishing surface.
A CMP polishing pad has one or more layers and may comprise, for example, felt fiber fabric impregnated with blown polyurethane. Other materials may be used to form suitable polishing pads. In general, the polishing pad is configured as a compromise polishing pad—that is a pad having sufficient rigidity to provide the desired planarity, and sufficient resilience to obtain the desired continuous tactile pressure between the pad and the substrate as the substrate thickness decreases during the polishing process.
Polishing pads are subjected to stress forces in directions both parallel to and normal to the pad-substrate interfacial surface. In addition, pad deterioration may occur because of the harsh chemical environment. Thus, the adhesion strength of the polishing pad to the platen must be adequate to resist the applied multidirectional forces during polishing, and chemical deterioration should not be so great that the pad-to-platen adhesion fails before the pad itself is in need of replacement.
Pores or depressions in pads typically become filled with abrasive materials during the polishing process. The resulting “glaze” may cause gouging of the surface being polished. Attempts to devise apparatus and “pad conditioning” methods for removing such “glaze” materials are illustrated in U.S. Pat. No. 5,569,062 to Karlsrud and U.S. Pat. No. 5,554,065 to Clover.
In any case, polishing pads are expendable, having a limited life and requiring replacement on a regular basis, even in a system with pad conditioning apparatus. For example, the working life of a typical widely used CMP polishing pad is about 20-30 hours.
Replacement of polishing pads is a difficult procedure. The pad must be manually pulled from the platen, overcoming the tenacity of the adhesive which is used. The force required to manually remove a 30-inch diameter pad from a bare aluminum or ceramic platen may exceed 100 lbf (444.8 Newtons) and may be as high as 150 lbf (667.2 Newtons) or higher. Manually applying such high forces may result in personal injury as well as damage to the platen and attached machinery.
BRIEF SUMMARY OF THE INVENTION
The invention comprises the application of a permanent, low adhesion, i.e., “non-stick,” coating of uniform thickness to the platen surface. Examples of such coating materials are fluorinated compounds, in particular, fluoropolymers including polytetrafluoroethylene (PTFE) sold under the trademark TEFLON® by DuPont, as well as polymonochlorotrifluoroethylene (CTFE) and polyvinylidene fluoride (PVF 2 ). The coating retains its tenacity to the underlying platen material, and its relatively low adhesion to other materials, at the temperatures, mechanical forces, and chemical action encountered in CMP processes.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention is illustrated in the following figures, wherein the elements are not necessarily shown to scale:
FIG. 1 is a perspective partial view of a polishing apparatus of the prior art;
FIG. 2 is a cross-sectional view of a portion of a polishing apparatus of the prior art, as taken along section line 2 - 2 of FIG. 1 ;
FIG. 3 is a cross-sectional view of a portion of a polishing apparatus of the invention;
FIG. 4 is a cross-sectional view of a portion of a platen and polishing pad of the invention, as taken along section line 4 - 4 of FIG. 3 ;
FIG. 5 is a top view of a polishing platen and pad of another embodiment of the invention; and
FIG. 6 is a cross-sectional view of a portion of a platen and polishing pad of the invention, as taken along section line 6 - 6 of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
Portions of a typical prior art chemical-mechanical polishing (CMP) machine 10 are illustrated in drawing FIGS. 1 and 2 . A platen 20 has attached to its upper surface 12 a polishing pad 14 by a layer of adhesive 16 . If it is desired to rotate platen 20 , its shaft 18 , attached to the platen 20 by flange 48 , may be turned by a drive mechanism, such as a motor and gear arrangement, not shown.
A substrate 30 such as a semiconductor wafer or optical lens is mounted on a substrate carrier 22 which may be configured to be moved in a rotational, orbital and/or vibratory motion by motive means, not shown, through shaft 24 . In a simple system, shafts 18 and 24 may be rotated in directions 26 and 28 as shown. The substrate 30 is held in the substrate carrier 22 by friction, vacuum or other means resulting in quick release following the polishing step. A layer 38 of resilient material may lie between the substrate 30 and substrate carrier 22 . The surface 32 of the substrate 30 which is to be planarized faces the polishing surface 34 of the polishing pad 14 and is compressed thereagainst under generally light pressure during relative movement of the platen 20 (and polishing pad 14 ).
In chemical-mechanical polishing (CMP), a polishing slurry 40 is introduced to the substrate-pad interface 36 to assist in the polishing, cool the interfacial area, and help maintain a uniform rate of material removal from the substrate 30 . The slurry 40 may be introduced, e.g., via tube 42 from above, or may be upwardly introduced through apertures, not shown, in the polishing pad 14 . Typically, the slurry 40 flows as a layer 46 on the pad polishing surface 34 and overflows to be discarded.
Upward removal of a polishing pad 14 from the upper surface 12 of the platen 20 is generally a difficult operation requiring high removal forces. Pad replacement is necessary on a regular basis, and the invention described herein and illustrated in drawing FIGS. 3 through 6 makes pad replacement easier, safer and faster.
Turning now to drawing FIGS. 3 and 4 , the prior art polishing apparatus of drawing FIG. 2 is shown with a platen 20 modified in accordance with the invention. Parts are numbered as in drawing FIG. 2 , with the modification comprising a permanent coating 50 of a “non-stick” or low-adhesion material applied to the upper surface 12 of the platen 20 , along coating/adhesive interface 54 . The polishing pad 14 is then attached to the coating 50 using a pressure-sensitive adhesive (PSA) 16 . It is common practice for manufacturers of polishing pads to supply pads with a high-adhesion PSA already fixed to the attachment surface 44 ( FIG. 1 ) of the pads. It has been found that the adhesion of polishing pads 14 to certain low-adhesion coatings 50 with conventional high-adhesion adhesives results in a lower release force, yet the bond strength is sufficient to maintain the integrity of the polishing pads 14 during the polishing operations. Typically, variables affecting the release force include the type and surface smoothness of the coating 50 , the type and specific adhesion characteristics of the adhesive 16 material, and pad size.
Referring to drawing FIGS. 5 and 6 , depicted is another version of the platen 20 which is coated with a low-adhesion coating 50 in accordance with the invention. In this embodiment, the platen 20 includes a network of channels 58 , and slurry 40 (not shown) is fed thereto through conduits 60 . The low-adhesion coating 50 covers the platen 20 and, as shown, may extend into at least the upper portions of channels 58 . Apertures 64 through the coating 50 match the channels 58 in the platen 20 . The polishing pad 14 and attached pressure-sensitive adhesive (PSA) 16 have through-apertures 62 through which the slurry 40 may flow upward from channels 58 and onto the polishing surface 34 of the polishing pad 14 .
The surface area of coating 50 to which the adhesive 16 may adhere is reduced by the apertures 64 . This loss of contact area between adhesive 16 and coating 50 of platen 20 may be compensated by changing the surface smoothness of the coating 50 or using an adhesive material with a higher release force.
Materials which have been found useful for coating the platen 20 include coatings based on fluoropolymers, including polytetrafluoroethylene (PTFE or “TEFLON®”), polymonochloro-trifluoroethylene (CTFE) and polyvinylidene fluoride (PVF 2 ). Other materials may be used to coat the upper surface 12 of platen 20 , provided that the material has the desired adherence, i.e., release properties, with available adhesives, may be readily cleaned, and has a long life in the mechanical and chemical environment of polishing.
Various coating methods may be used. The platen 20 may be coated, for example, using any of the various viable commercial processes, including conventional and electrostatic spraying, hot melt spraying, and cementation.
In the application of one coating process to a modification of the platen 20 , the upper surface 12 of the platen 20 is first roughened to enhance adhesion. The coating material 50 is then applied to the upper surface 12 by a wet spraying or dry powder technique, as known in the art. In one variation of the coating process, white-hot metal particles, not shown, are first sprayed onto the uncoated base surface and permitted to cool, and the coating 50 is then applied. The metal particles reinforce the coating 50 of low-adhesion material which is applied to the platen 20 .
The result of this invention is a substantial reduction in release force between polishing pad 14 and platen 20 to a level at which the polishing pad may be removed from the platen 20 with minimal effort, yet the planar attachment of the polishing pad 14 to the platen 20 during polishing operations will not be compromised. The particular combination(s) of coating 50 and adhesive 16 material which provide the desired release force may be determined by testing various adhesive formulations with different coatings.
Another method for controlling the release force is the introduction of a controlled degree of “roughness” in the coating surfaces 52 (including surfaces of fluorocarbon materials) for changing the coefficient of friction. The adhesion of an adhesive 16 material to a coating 50 may be thus controlled, irrespective of the pad construction, size or composition.
The use of a coating 50 of the invention provides useful advantages in any process where a polishing pad 14 must be periodically removed from a platen 20 . Thus, use of the coating 50 is commercially applicable to any polishing method, whether chemical-mechanical polishing (CMP), chemical polishing (CP) or mechanical polishing (MP), where a polishing pad 14 of any kind is attached to a platen 20 .
EXAMPLE
A piece of flat aluminum coated with polytetrafluoroethylene (PTFE) was procured. The particular formulation of PTFE applied to the aluminum was MALYNCO 35011 BLACK TEFLON™.
Conventional CMP polishing pad samples were obtained in a size of 3.7×4.2 inches (9.4×10.67 cm.). The area of each pad was 15.54 square inches (100.3 square cm.). These pads were identified as SUBA IV PSA 2 adhesive pads and were obtained from Rodel Products Corporation of Scottsdale, Ariz.
The polishing pads included a polyurethane-based pressure-sensitive adhesive (PSA2) on one surface. The pads were placed on the coated aluminum, baked at 53° C. for two hours under slight compression, and cooled for a minimum of 45 minutes, thereby bonding the pads to the PTFE surface.
Samples of the same pad material were similarly adhered to an uncoated aluminum surface of a polishing platen for comparison as test controls.
Tests were conducted to determine the force required to remove each pad from the surface coating and the uncoated surfaces. The average measured removal forces were as follows:
Removal force from MALYNCO 35011 BLACK TEFLON™ coated aluminum: 1.08 lbf.
Removal force from uncoated aluminum: 11.5 lbf.
Extrapolation to actual production size platens of 30-inch diameter indicates that pad removal forces may be reduced from about 100-150 lbf. (about 444.8-667.2 Newtons) to about 15 lbf. to about 25 lbf. (about 66 to 112 Newtons). This force is sufficient to maintain pad-to-platen integrity during long-term polishing but is a significant reduction in the force required for pad removal and replacement.
It is apparent to those skilled in the art that various changes and modifications, including variations in pad type and size, platen type and size, pad removal procedure, etc., may be made to the polishing apparatus and method of the invention as described herein without departing from the spirit and scope of the invention as defined in the following claims.
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An improvement in a polishing apparatus for planarizing substrates comprises a tenacious coating of a low-adhesion material to the platen surface. An expendable polishing pad is adhesively attached to the low-adhesion material, and may be removed for periodic replacement at much reduced expenditure of force. Polishing pads joined to low-adhesion materials such as polytetrafluoroethylene (PTFE) by conventional adhesives resist distortion during polishing but are readily removed for replacement.
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BACKGROUND OF THE INVENTION
This invention relates to an internal combustion engine in which the air-to-fuel ratio of the air-fuel mixture supplied into the combustion chambers of the engine is controlled utilizing feedback techniques in accordance with the composition of the exhaust gases discharged from the combustion chambers of the engine.
As is well known, it is now required from standpoints of exhaust gas control and fuel economy to accurately control the air-to-fuel ratio of the air-fuel mixture supplied into the combustion chambers of an internal combustion engine at a required value. Especially when the exhaust system of the internal combustion engine is equipped with a three-way catalytic converter capable of reducing nitrogen oxides as well as oxidizing hydrocarbons and carbon monoxide, the three-way catalytic converter requires to be supplied with an exhaust gases produced by combustion of the air-fuel mixture having approximately stoichiometric air-to-fuel ratio in the combustion chambers in order to allow the converter to function effectively and sufficiently. However, usual carburetors can not control so accurately the air-to-fuel ratio of the mixture supplied therefrom due to their constructions and characteristics.
In order to satisfy the above requirements, it has been proposed that the air-to-fuel ratio of the mixture supplied into the combustion chambers is controlled at the stoichiometric air-to-fuel ratio utilizing feedback techniques wherein the fuel amount supplied into the combustion chambers is directly or indirectly regulated in response to the composition of the exhaust gases which composition are detected by an exhaust gas sensor located in an exhaust passage communicated downstream of the combustion chambers of the engine. This method has been realized depending on the fact that the composition of the exhaust gases are in close relationship with the air-to-fuel ratio of the mixture supplied into the combustion chambers of the engine. In a system for performing the above method, the regulation of the fuel amount supplied to the combustion chambers is accomplished by controlling the air amount inducted through an additional air passage which communicates a main well of the carburetor with the atmosphere. The additional air passage is formed in addition to a main air bleed which is arranged to induct atmospheric air into the main well. The control of the air amount inducted through the additional air passage is carried out by valve means which is arranged to close or open in on-and-off manner the additional air passage, and to increase or decrease the air amount inducted therethrough than a predetermined amount by decreasing or increasing the time rate for closing the additional air passage than a predetermined rate.
However, this system employing such type of the inducted air amount control mechanism has encountered the following difficulty: when the throttle valve of the carburetor is opened, the additional air passage is supplied with a strong vacuum which is applied through a main discharge nozzle and the main well. However, when the engine is decelerated and the throttle valve is abruptly almost closed, the main discharge nozzle is subjected to a weak vacuum near the atmospheric pressure, but the strong vacuum is still remains in the additional air passage when the passage is closed by the valve means and accordingly the fuel in the main well is sucked and stayed in the additional air passage. The sucked and stayed fuel is thereafter discharged through the main discharge nozzle when the passage is opened and therefore invites disturbance of the control of the fuel amount discharged through the main discharge nozzle. This fuel control disturbance results in so-called car knock or undesirable frequent change of the vehicle speed.
SUMMARY OF THE INVENTION
It is, therefore, a principal object of the present invention to provide an improved internal combustion engine capable of well controlling the air-fuel ratio of the air-fuel mixture fed into the combustion chambers of the engine at a desired value by employing feedback techniques in response to the composition of the exhaust gases of the engine, maintaining stable operation of the engine.
Another object of the present invention is to provide an internal combustion engine equipped with an improved carburetor which can accurately control the fuel amount discharged through the main discharge nozzle of the carburetor to feed the combustion chambers of the engine with the air-fuel mixture of a required air-fuel ratio in response to signals transmitted from a control circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the present invention will become more apparent upon reference to the succeeding description thereof, and to the drawing illustrating the preferred embodiments thereof, in which:
FIG. 1 is a schematical section view showing a part of a preferred embodiment of an internal combustion engine in accordance with the present invention; and
FIG. 2 is a section view of a part of a carburetor which is used in another preferred embodiment of the engine in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1 there is shown a preferred embodiment of a part of an internal combustion engine in accordance with the present invention in which a carburetor 10 has a throttle valve 12 rotatably disposed, as usual, within the air-fuel mixture induction passage 14. The induction passage 14 is, as usual, communicable with the combustion chambers of the internal combustion engine (not shown). Each combustion chamber is defined by a cylinder head and a piston crown (they are not shown). A main venturi portion 16 and a secondary venturi portion 18 are located upstream of the throttle valve 12. Opened to the secondary venturi portion 18 is a main discharge nozzle 20 which is communicates with a main well 22 connected at its top portion to a main air bleed orifice 24 for communicating the main well 22 with the atmosphere. An emulsion tube 26 connected to the main air bleed orifice 24 is disposed within the main well 22 to well mix the fuel in the main well 22 with air from the main air bleed orifice 24. The main well 22 is, as customary, communicated with the float bowl 28 through a main jet 30. An additional air passage 32 or additional air passage means formed in the body casting portion of the carburetor 10 is arranged to communicate the main well 22 with the atmosphere to introduce additional air into the main well 22 in addition to the air from the main air bleed orifice 24.
A valve member 34 of an electromagnetic valve 36 or valve means is disposed at a first portion of the additional air passage 32 to be projected for closing the first portion and to be withdrawn for opening the first portion. The electromagnetic valve 36 is arranged to take first and second states. In the first state, the valve member 34 is operated and moved to increase the flow amount of air inducted through the additional air passage 32 than a predetermined amount in order to decrease the fuel amount discharged from the main discharge nozzle 20 and to make leaner the air-fuel ratio of the air-fuel mixture fed into the combustion chambers toward a predetermined level. In the second state, the valve member 34 is, on the contrary, operated and moved to decrease the flow amount of the air than the predetermined amount in order to increase the fuel amount discharged from the main discharged nozzle 20 and to make richer the air-fuel ratio of the air-fuel mixture fed into the combustion chambers toward the predetermined level. These operation manners of the valve member 34 of the electromagnetic valve 36 is, in this instance, accomplished by decreasing the rate of time for closing the first portion of the additional air passage 32 than a predetermined rate in the first state, and increasing the rate of time for closing the first portion than the predetermined rate in the second state. It will be understood that the electromagnetic valve may be replaced with other valves such as a diaphragm operated valve.
As clearly shown in FIG. 1, an air induction passage 38 or an air induction passage means is formed in the body casting portion of the carburetor 10 to connect portions of the additional air passage 32 upstream and downstream of the first portion where the valve member 34 is disposed so that the portion downstream of the first portion always communicates with the atmosphere therethrough even when the valve member 34 completely closes the first portion of the additional air passage 32. It is preferable to form the diameter of the opening of the air induction passage 38 as small as possible since the passage 38 is formed merely for the purpose of establishing the communication between the portion of the passage 32 downstream of the first portion and the atmosphere. However, the diameter is more preferably about 0.4 mm or more in order to prevent clogging of the opening of the passage 38 with dusts.
The electromagnet of the electromagnetic valve 36 is electrically connected to a control circuit 40. The control circuit 40 is arranged to generate a first command signal for placing the valve 36 into the first state and a second command signal for placing the valve 36 into the second state. The control circuit 40 is, in turn, electrically connected to an exhaust gas sensor 42 which is disposed within the exhaust passage 44 of the exhaust system of the engine upstream of an exhaust gas purifying device 46. The exhaust gas sensor 42 is arranged to generate a first information signal (which may be a voltage signal) for causing the control circuit 40 to generate the first command signal when the exhaust gases passing through the exhaust passage 44 have a first composition representing that the combustion chambers are fed with an air-fuel mixture of an air-fuel ratio richer than a predetermined level, and a second information signal for causing the control circuit 40 to generate the second command signal when the exhaust gases passing through the exhaust passage 44 have a second composition representing that the combustion chambers are fed with an air-fuel mixture of an air-fuel ratio leaner than the predetermined level.
The exhaust gas sensor 42 may be an oxygen (O 2 ) sensor, a nitrogen oxides (NOx) sensor, a carbon monoxide (CO) sensor, a carbon dioxides (CO 2 ) sensor or a hydrocarbon (HC) sensor which are respectively detect the concentration of O 2 , NOx, CO, CO 2 or HC contained in the exhaust gases discharged from the combustion chambers. When the exhaust purifying device is a so-called three-way catalytic converter capable of reducing NOx as well as oxidizing CO and HC in the exhaust gases, the predetermined level of the air-fuel ratio of the air-fuel mixture supplied into the combustion chambers is stoichiometric one (14.8:1) which is required for effectively functioning the three-way catalytic converter. In case of using as the exhaust gas purifying device an oxidation catalytic converter or a reactor, the predetermined level will be selected to effectively functioning it.
In order to operate the electromagnetic valve 36 in the above discussed manner, the control circuit 40 of this case is arranged to set, as a reference voltage, a specified voltage signal generated by the exhaust gas sensor 42 when the predetermined level of the air-fuel mixture is supplied into the combustion chambers, and to generate the first command signal when the level of the voltage signal from the sensor 42 is lower than that of the specified voltage signal representing the combustion chambers are fed with the air-fuel mixture of the air-fuel ratio leaner than the predetermined level and the second command signal when the level of the voltage signal from the sensor 42 is higher than that of the specified voltage signal representing that the combustion chambers are fed with the air-fuel mixture of the air-fuel ratio richer than the predetermined level.
With the arrangement hereinbefore discussed, when the combustion chambers of the engine 10 are fed with the air-fuel mixture of the air-fuel ratio richer than the predetermined level such as stoichiometric air-fuel ratio, the valve member 34 of the electromagnetic valve 36 is operated to increase the flow amounts of air inducted through the additional air passage 32 into the main well 22. Then, the flow amount of fuel through the main discharge nozzle 20 is decreased and accordingly the air-fuel ratio of the air-fuel mixture fed into the combustion chambers is made leaner. On the contrary, when the combustion chambers are fed with the air-fuel mixture of the air-fuel ratio leaner than the predetermined level, the valve member 34 is operated to decrease the flow amount of air inducted through the additional air passage 32 into the main well 22. Then, the flow amount of fuel through the main discharge nozzle 20 is increased and accordingly the air-fuel mixture fed into the combustion chambers are enriched. As discussed above, the air-fuel ratio of the air-fuel mixture supplied into the combustion chambers can be always controlled at the predetermined level.
When the vacuum generated at the secondary venturi portion 18 of the carburetor 10 or the vacuum adjacent the main discharge nozzle 20 is abruptly decreased toward the atmospheric pressure due to closing of the throttle valve 12 occurred during deceleration of the engine, and additionally the valve member 34 of the electromagnetic valve 36 completely closes the first portion of the additional air passage 32, a small amount of atmospheric air is inducted through the air induction passage 38 into the additional air passage downstream of the first portion where the valve member 34 is disposed to decrease the vacuum within the additional air passage 32 for changing the vacuum into the atmospheric pressure. Accordingly, by virtue of the air induction passage 38, the fuel from the main well 22 is not forced to flow back into and does not stay within the additional air passage 32.
In this connection, if the air induction passage 38 according to the present invention is not formed in the carburetor 10, the fuel within the main well 22 is forced to flow back into the additional air passage 32 and stays therein when the vacuum at the secondary venturi portion 18 is abruptly decreased toward the atmospheric pressure and the valve member 34 of the electromagnetic valve 36 completely closes the first portion of the additional air passage 32. At this time, the fuel discharge through the main discharge nozzle 20 is momentarily stopped. When the valve member 34, thereafter, opens the first portion of the additional air passage 32 at the same condition, the fuel stayed within the additional air passage 32 is abruptly sucked into the main well 22 and accordingly the amount of fuel discharged through the main discharge nozzle 20 is momentarily increased. This disturbance of the fuel amount discharged through the main discharge nozzle 20 results in engine surge or changes in engine speed which contributes to so-called car knock or undesirable frequent change of vehicle speed.
FIG. 2 illustrates a part of the carburetor of the engine of another preferred embodiment in accordance with the present invention, in which the other part of the engine is omitted for the purpose of simplicity of illustration since the other part is same as the embodiment of FIG. 1. As shown, a first portion 32a of the additional air passage 32 or a first additional air passage is formed in the body casting portion of the carburetor 10 to be communicated at its one end with the main well 22 through a pipe 48 and at its other end with an atmospheric chamber 50 defined by a diaphragm 52 through a valve seat 54. The valve seat 54 is, as seen, disposed at a portion where the first additional air passage 32a opens to the atmospheric chamber 50, and having an opening formed through the valve seat 54, the opening being communicated with the first additional air passage 32a. A second portion 32b of the additional air passage 38 or a second additional air passage is communicated at its one end with the atmospheric chamber 50 and at the other end with the atmosphere through a pipe 56. Movably disposed on the valve seat 54 is a valve member 58 which is secured to the central portion of the diaphragm 52. The valve member 58 has a portion made of a magnetic material or a material which is magnetically affected, and arranged to be attracted by a core 60 of an electromagnet 62 such that the valve member 58 detaches from the valve seat 54 to establish communication between the first and second additional air passages 32a and 32b when electric current is applied to a solenoid coil 64 surrounding the core 60 to energize the core 60, or be urged to contact with the valve seat 54 by the action of a spring 66 for blocking communication between the first and second additional air passages 32a and 32b when the electric current is not applied to the solenoid coil 64 to de-energize the core 60. As seen, the spring 66 is disposed within a groove formed at the inner surface of the core 60 of a cylindrical form. The air induction passage 38 is formed to connect the first and second additional air passages 32a and 32b. Disposed within the air induction passage 38 is an orifice 38a whose opening has a diameter of about 0.4 mm or more. The electromagnet 62 is arranged to take a first state wherein the energizing time rate of the core 60 thereof is increased than a predetermined rate to make leaner the air-fuel ratio of the air-fuel mixture fed into the combustion chambers of the engine, and a second state wherein the energizing time rate of the core 60 thereof is decreased than the predetermined rate to make richer the air-fuel ratio of the air-fuel mixture fed into the combustion chambers of the engine. In this case, the control circuit is arranged to generate the first command signal to place the electromagnet 62 in the first state when receiving the first information signal form the exhaust gas sensor 42, and the second command signal to place the electromagnet 62 in the second state when receiving the second information signal from the exhaust gas sensor 42.
It will be seen that the valve mechanism of the embodiment of FIG. 2 improves response characteristics and durability of the valve member 58 since the valve mechanism does not employ a member along which the valve member 58 is slidably moved.
While only the air induction passage 38 applied to the main circuit of the carburetor 10 is shown and described through the embodiments of FIGS. 1 and 2, it will be understood that the air induction passage 38 may be applied to the low-speed circuit of the carburetor.
As is apparent form the foregoing discussion, according to the present invention, the undesirable disturbance of control of the air-fuel ratio of the air-fuel mixture fed into the combustion chambers is effectively prevented even during deceleration of the engine and therefore stable operation of the engine is always maintained.
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The air-fuel ratio of the air-fuel mixture supplied to the combustion chambers of an internal combustion engine is regulated at a required value by controlling the air amount inducted through an additional air passage into the main well which communicates with the main discharge nozzle of a carburetor. The air amount control is accomplished by valve means which is arranged to open and close in on-and-off manner the additional air passage. An air induction passage is further formed to communicate the additional air passage downstream of the valve means with the atmosphere to introduce further air when the valve means closes the additional air passage and vacuum still remains therewithin.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims priority of Korean Patent Application Number 10-2012-0147787 filed Dec. 17, 2012, the entire contents of which application are incorporated herein for all purposes by this reference.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to a variable compression ratio device and an internal combustion engine using the same, and more particularly, to a variable compression ratio device, which varies the compression ratio by increasing or decreasing the volume of a combustion chamber, and an internal combustion engine using the same.
[0004] 2. Description of Related Art
[0005] In general, the compression ratio of an internal combustion engine is represented by the largest volume of a combustion chamber prior to compression and the smallest volume of the combustion chamber after compression in a compression stroke of the internal combustion engine.
[0006] The output of the internal combustion engine increases as the compression ratio of the internal combustion engine is increased. However, if the compression ratio of the internal combustion engine is too high, so-called knocking occurs, and this event decreases the output of the internal combustion engine and also results in overheating of the internal combustion engine, a failure in a valve or piston of the internal combustion engine, and so on.
[0007] Accordingly, the compression ratio of the internal combustion engine is set to a specific value within an appropriate range prior to the occurrence of knocking. As such, because the air-fuel ratio and output of the internal combustion engine can be improved by properly varying the compression ratio according to the load of the internal combustion engine, various approaches are being proposed to vary the compression ratio of the internal combustion engine.
[0008] These approaches for varying the compression ratio of the internal combustion engine mostly employ methods that vary the volume of the compression chamber during a compression stroke. For example, there have been proposed methods that vary the height of the top dead center of a piston during a compression stroke, or increase or decrease the volume of a sub-compression chamber provided in a cylinder head.
[0009] Varying the height of the top dead center of a piston tends to make the structure of the internal combustion engine complicated. Therefore, it will be desirable to vary the compression ratio by providing a sub-compression chamber in a cylinder head to make the structure simple and achieve great improvement in air-fuel ratio.
[0010] The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
SUMMARY OF INVENTION
[0011] The present invention has been made in an effort to provide a variable compression ratio device having the advantage of contributing to the improvement of the air-fuel ratio and output of an internal combustion engine by providing a sub-compression chamber in a cylinder head and varying the compression ratio of a main compression chamber, and an internal combustion engine using the same.
[0012] Various aspects of the present invention provide a variable compression ratio device including a main piston that moves in a reciprocating manner; a main combustion chamber a volume of which is varied by the main piston, a sub-compression chamber communicating with the main combustion chamber, a sub-piston configured to reciprocate in the sub-compression chamber so as to vary a volume of the sub-compression chamber, and a sub-piston reciprocating unit that reciprocates the sub-piston.
[0013] The sub-compression chamber may be inclined at a predetermined angle with respect to the main compression chamber. The bottom surface of the sub-piston may be inclined at an angle substantially the same as the sub-compression chamber with respect to the main compression chamber. The sub-compression chamber may be of a cylindrical shape.
[0014] The sub-piston reciprocating unit may include a connecting rod one end of which is connected to the sub-piston, an eccentric cam coupled to the other end of the connecting rod, and a rotating unit that rotates the eccentric cam. The eccentric cam may be press-fit to the other end of the connecting rod.
[0015] The eccentric cam may be of a circular shape, and an eccentric rotary shaft may be provided in the eccentric cam to rotatably connect the eccentric cam to the rotating unit.
[0016] The rotating unit may include a worm wheel gear integrally and rotatably mounted at a tip end of the rotary shaft; a worm gear engaged with the worm wheel gear, and a driving motor connected to the worm gear to rotate the worm gear. The rotating unit may include a continuous variable valve timing apparatus having a vane integrally and rotatably mounted at a tip end of the rotary shaft.
[0017] The continuous variable valve timing apparatus may include a connecting rod whose one end is connected to the sub-piston, a crank-like rotary shaft coupled to the other end of the connecting rod; a worm wheel gear integrally and rotatably mounted at a tip end of the rotary shaft, a worm gear engaged with the worm wheel gear, and a driving motor connected to the worm gear to rotate the worm gear.
[0018] Various other aspects of the present invention provide an internal combustion engine including at least one cylinder each having the variable compression ratio device, a cylinder block which forms the cylinder, and in which a main piston is inserted and reciprocates, and a cylinder head configured to cover the cylinder block from the top, and having the sub-combustion chamber formed therein. The at least one cylinder may include four cylinders. The internal combustion engine may be an internal combustion engine using the Atkinson cycle.
[0019] In a variable compression ratio device of the present invention, a sub-combustion chamber is formed in a cylinder head to communicate with a main combustion chamber, and a sub-piston is provided in the sub-combustion chamber to vary the volume. Therefore, the compression ratio can be easily varied since the total volume of the main compression chamber and the sub-compression chamber is varied in accordance with a reciprocating stroke of the sub-piston.
[0020] With this simple structure, vehicle weight reduction and cost savings can be achieved, and the compression ratio of the internal combustion engine can be easily adjusted. As a result, the air-fuel ratio and output of the internal combustion engine can be effectively improved.
[0021] Moreover, if the present invention is applied to an internal combustion engine using the Atkinson cycle, better air-fuel ratios and torque can be attained.
[0022] The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a perspective view of an exemplary variable compression ratio device according to the present invention.
[0024] FIG. 2 is a perspective view of an exemplary variable compression ratio device applied to a four-cylinder internal combustion engine according to the present invention.
[0025] FIG. 3 is a perspective view of an exemplary crank web according to the present invention.
[0026] FIG. 4 illustrates the operation of an exemplary variable compression ratio device according to the present invention.
[0027] FIG. 5 is a perspective view of another exemplary variable compression ratio device applied to a four-cylinder internal combustion engine according to the present invention.
[0028] FIG. 6 is a perspective view of another exemplary variable compression ratio device applied to a four-cylinder internal combustion engine according to the present invention.
DETAILED DESCRIPTION
[0029] Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
[0030] Referring to FIGS. 1 to 3 , a sub-compression chamber 20 is formed above a cylinder head 10 forming a main compression chamber 10 a so as to communicate with the main compression chamber 10 a.
[0031] The sub-compression chamber 20 is inclined at a predetermined angle with respect to the main combustion chamber 10 a. The sub-compression chamber 20 usually, but not necessarily, has a cylindrical shape, and may have a different shape.
[0032] A sub-piston 30 is inserted into the sub-compression chamber 20 and is movable along the length of the sub-compression chamber 20 .
[0033] When the sub-piston 30 reciprocates along the length of the sub-compression chamber 20 , the volume of the sub-compression chamber 20 communicating with the main compression chamber 10 a is varied.
[0034] Accordingly, the total volume of the combustion chamber, which is equal to the sum of the volume of the main compression chamber 10 a and the volume of the sub-compression chamber 10 a, is varied, and hence the compression ratio of an internal combustion engine can be varied.
[0035] A connecting rod 40 , one end of which is connected to the sub-piston 30 , is provided as a reciprocating unit for reciprocating the sub-piston 30 along the length of the sub-compression chamber 20 . An eccentric cam 50 is fitted and coupled to the other end of the connecting rod 40 . The eccentric cam 50 is connected to be rotatable by an appropriate rotating unit.
[0036] When the eccentric cam 50 rotates by the rotating unit, the connecting rod 40 is pulled outward of the sub-compression chamber by the eccentric cam 50 in a direction of increasing the volume of the sub-compression chamber, or pushed inward of the sub-compression chamber by the eccentric cam 50 in a direction of decreasing the volume of the sub-compression chamber, whereby the volume of the sub-compression chamber is varied.
[0037] A circular coupling hole 40 a is formed on the other end of the connecting rod 40 , and a circular eccentric cam 50 is inserted and coupled to the coupling hole 40 a. A rotary shaft 50 a of the eccentric cam 50 is located to be outwardly eccentric from the center of the eccentric cam 50 and the center of the coupling hole 40 a. Accordingly, when the rotary shaft 50 a rotates by the rotating unit of the eccentric cam 50 , the eccentric cam 50 eccentrically rotates around the rotary shaft 50 a.
[0038] The rotating unit includes a worm wheel gear 60 integrally and rotatably mounted at a tip end of the rotary shaft 50 a, a worm gear 62 engaged with the worm wheel gear 60 , and a driving motor 64 connected to the worm gear 62 so as to rotate the worm gear 62 . One will appreciate that these integral components may be monolithically formed.
[0039] Accordingly, when the driving motor 64 rotates the worm gear 62 as it is driven upon receipt of a control signal from a controller, the rotation of the worm gear 62 is transferred to the worm wheel gear 60 , and the rotary shaft 50 a rotates together with the rotation of the worm wheel gear 60 .
[0040] Referring to FIG. 2 , a variable compression ratio device of the present invention may be applied to a four-cylinder internal combustion engine. One would appreciate that a variable compression ratio device of the present invention can be applied to other internal combustion engines.
[0041] A main piston 70 is provided in each cylinder, and the volume of a main combustion chamber 10 a is varied in accordance with the up-and-down movement of the main piston 70 .
[0042] A sub-combustion chamber 20 is provided in the cylinder head 10 so as to communicate with the main combustion chamber 10 a of each cylinder, and the sub-piston 30 is movably installed in each sub-combustion chamber 20 so as to vary the volume of the sub-combustion chamber 20 .
[0043] One end of the connecting rod 40 is integrally connected to the sub-piston 30 , and the eccentric cam 50 is coupled, for example, by press-fitted, to the other end of the connecting rod 40 .
[0044] Each eccentric cam 50 is integrally and rotatably connected to a rotary shaft 50 a, and the rotary shaft 50 a is connected to a driving motor 64 through the worm wheel gear 60 and the worm gear 62 . Thus, the rotary shaft 50 a rotates each eccentric cam 50 upon receipt of rotary force of the driving motor 64 , thereby varying the compression ratio of each cylinder. One will appreciate that the integral components may be monolithically formed.
[0045] Referring to FIG. 3 , the sub-piston 30 goes down to the bottom end of the sub-compression chamber 20 by the rotation of the rotary shaft 50 a, and therefore the total volume of the main compression chamber and the sub-compression chamber is mostly limited to the volume of the main compression chamber.
[0046] Consequently, the compression ratio is adjusted in accordance with the up-and-down movement of the main piston 70 . As the sub-compression chamber occupies little volume in this case, the highest compression ratio is achieved when the main piston 70 goes up as high as the top dead center.
[0047] Since the sub-compression chamber 20 is inclined at a predetermined angle to the cylinder head 10 , the bottom surface of the sub-piston 30 is also formed to have the same inclination angle as the sub-compression chamber 20 . As such, it is possible to prevent the sub-compression chamber 20 from communicating with the main compression chamber so that the volume of the sub-compression chamber 20 in this case is nearly zero when the sub-piston 30 goes down to the lowest level.
[0048] Referring to FIG. 4 , the sub-piston 30 goes up as high as the top end of the sub-compression chamber 20 by the rotation of the rotary shaft 50 a, and hence the total volume of the main compression chamber and the sub-compression chamber is at the highest level.
[0049] Accordingly, the compression ratio is adjusted in accordance with the up-and-down movement of the main piston 70 . Since the volume of the sub-compression chamber and the volume of the main compression chamber are added to increase the total volume to the highest level, the lowest compression ratio can be achieved when the main piston 70 goes up as high as the top dead center.
[0050] Referring to FIG. 5 , while the sub-piston 30 is moved up and down by means of the connecting rod 40 and the eccentric cam 50 , the sub-piston 30 may also be moved up and down by means of the connecting rod 40 , by using a crank-like rotary shaft 50 b and connecting the other end of the connecting rod 40 to the crank-like rotary shaft 50 b.
[0051] Moreover, a continuously variable valve timing (CVVT) apparatus may be used, instead of the driving motor 64 , as a way of rotating the rotary shaft 50 a.
[0052] For example, as shown in FIG. 6 , a vane type continuous variable valve timing apparatus 80 is installed at a tip end of the rotary shaft 50 a, and a vane of the continuous variable valve timing apparatus 80 is integrally and rotatably mounted to the rotary shaft 50 a. One will appreciate that these integral components may be monolithically formed.
[0053] When the vane is rotated by controlling the inflow and outflow of hydraulic fluid to and from the variable valve timing apparatus 80 , the rotary shaft 50 a rotates in accordance with the rotation of the vane, thereby reciprocating the sub-piston 30 .
[0054] Meanwhile, if the present invention is applied to an internal combustion engine using the Atkinson cycle, better air-fuel ratios and torque can be attained.
[0055] For convenience in explanation and accurate definition in the appended claims, the terms “up” or “down”, “inward” or “outward”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
[0056] The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
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A variable compression ratio device and an internal combustion engine are disclosed. The variable compression ratio device includes a main piston that moves in a reciprocating manner, a main combustion chamber having a volume that is varied by the main piston, a sub-compression chamber communicating with the main combustion chamber; a sub-piston configured to reciprocate in the sub-compression chamber to vary a volume of the sub-compression chamber; and a sub-piston reciprocating unit that reciprocates the sub-piston. Accordingly, the air-fuel ratio and output of the internal combustion engine can be improved.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of image recognition. More specifically, it relates to a method and an apparatus for facial image acquisition and recognition, wherein an active near infrared (NIR) light within invisible light spectrum is applied to illuminate a target face.
BACKGROUND OF THE INVENTION
[0002] Face recognition is a biometric technology in which the technology related to computers, image processing, and pattern recognition is also involved to perform person identification based on facial images. Recently, especially after 9.11 terror attacks, many countries in the world have attached a great importance to their public security. Accordingly, face recognition technology has been greatly noticed much more than ever before.
[0003] Biometric authentication refers to a class of high tech recognition technologies that use human biometric traits to carry out person verification and identification. Biometric traits of a person, such as fingerprint, palm print, iris, deoxyribonucleic acid (DNA), are unique and stable for the individual; they cannot be duplicated, stolen and forgotten. Because each person's characteristics are distinct from others, it is possible to accurately identify a person by using his/her unique biometrics. Existing biometric recognition methods generally include face recognition, fingerprint recognition, sound recognition, palm print recognition, signature recognition, eye iris, retina recognition and so on.
[0004] As compared to other recognition technologies, face recognition technique is of many advantages such that it is natural, simple and convenient, easy to operate, user friendly, contactless, and non-intrusive, etc. It can complete the recognition task without incurring much disturbance. With this technology, people no longer need to worry about touching his fingerprint on the fingerprint device, or talking to the microphone, or looking into an iris scanner required by conventional recognition in the prior art. A face can be recognized when a person show his face to the camera. Therefore, the face recognition technology can be widely applied to access control, machine readable traveling documents (MRTD), e-passport, anti-terrorism, ATM, computer logon, safe cabinet, time attendance, and so on.
[0005] Typical face recognition applications include the following modes:
[0006] Identification (1:N match) to determine a person's ID: A system (1) acquires the face image data, (2) extracts facial features or record from the image, (3) compares it with all or part of the records of enrolled persons in database to calculate the similarity scores, and (4) produce a sorted list based on the similarity score. Finally, the system outputs the persons ID corresponding to the top most similarity if the top most similarity is above an acceptance threshold; otherwise concludes that the person is not identified.
[0007] Verification (1:1 match) to verify whether the claimant. In this case, the system needs just to compare the facial record extracted from the image with that of the claimed person to give the similarity score. The system either accepts the claimant if the similarity score is above an acceptance threshold, or reject if otherwise.
[0008] Surveillance: Using the techniques of face image acquisition and face recognition to track a person in the surveillance area and determines his location.
[0009] Monitoring: To discover the faces in the surveillance area, far or near, regardless of their locations, track them and separate them from the background, compare the facial features with those in the database. The entire process is automatic, continuous, and real-time.
[0010] The above application modes can be widely applied in the following domains:
[0011] Personnel identification and indexing: These can be used in computer/network security, bank services, smart card, access control, frontier control, etc.
[0012] ID card: This can be used in voter registration, ID card, passport, driver's license, work identification and so on.
[0013] Computer information safeguarding system: This uses the facial features to recognition user, safeguards the computer information.
[0014] Crime suspect recognition system: This system stores face pictures and recognizes faces in analyzing incidents.
[0015] Long-distance person identification: This is applied in surveillance, monitoring, TV, traffic control, enemy-friend recognition and so on.
[0016] A face recognition process is illustrated in FIG. 1 . It consists of following three modules:
[0017] Image acquisition module 10 : It captures face image or video images through image acquisition equipment (for example video camera, digital camera and so on), then, then sends these images or video to a computer.
[0018] Feature extraction module 20 : Residing in a computer processor, this module examines the input image, detects the face, locate facial features such as eyes and mouth, normalize the face in pose and illumination, and extracts face features (face code).
[0019] Feature matching module 30 : Also residing in the computer, it compares the face features extracted from the input image information (face code) with those stored in the database 40 , and find the best matched one.
[0020] Obviously, the face feature database should be set up before the face recognition process. Therefore, as shown in FIG. 2 , a face recognition system should have two main parts: Face Recognition (Part A), and Face Enrollment (Part B). Among them, the purpose of Part B is to register related personal information for the person to be enrolled, extract the face code of the person, and store the information and face code in the database for face recognition process in the future.
[0021] Both enrollment and recognition (Parts A and B) include the image acquisition and feature extraction modules. Of these, the face recognition part has an additional feature matching (comparing) module, while the face enrollment part has a data saving module.
[0022] Face feature extraction process 20 is composed of several steps: face detection or tracking 201 , facial feature localization and face normalization 202 , face feature extraction (face code generation) 203 . The face detection finds the face in the input image or video image sequence, so that the face is separated from the background; the face tracking tracks detected the faces in video image sequence, face normalization or alignment uses localized facial landmarks (eyes and/or mouth) to normalize the geometry of the face to a standard pose and normalize the lighting to a standard illumination condition, face feature extraction calculates the face code from normalized face image.
[0023] Face matching 30 compares the face code from the input with those of the enrolled persons in the database 40 , one by one in turn, computes the similarity matching scores, and gives a decision for verification or identification after referring to a similarity threshold.
[0024] To achieve reliable and accurate accuracy, face recognition should be performed based on intrinsic factors of the face only, mainly of 3D shape and reflectance of the facial surface. Variations brought about by extrinsic factors, including hairstyle, eyeglasses, expression, posture, and environmental lighting, should be reduced or eliminated in order to achieve high performance.
[0025] Most of existing face recognition technologies are based on visible light images. Such technologies have difficulties in adapting to changes in environmental lighting: Changes in lighting cause changes in facial features; therefore, their accuracy deteriorates when the lighting of the face recognition environment differs from that of the face enrollment environment, for example, US Patent US2001/003102A1.
[0026] The research shows that the difference of facial image for same person by light change is much bigger than that of different persons. (Sees also Yael Adnin, Yael Moses and Shimon Ullman, “Face recognition: The problem of compensating for changes in illumination direction”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 19, No. 7, 1,997, pp. 712-732). Existing face recognition technology depends on “passive” light source, that is, environmental light sources. Unfortunately, in real application, the environmental lights vary, and are not controlled. A change in environment light changes the captured facial image dramatically. This in turn significantly changes extracted face features, and causes significant drop in recognition accuracy.
[0027] Suppose for each point Pi, there is a vector n i =(n x ,n y ,n z ) T , n T i is a unit vector, that is ∥n∥=1; Assume that the light source is point source, the direction is s=(s x ,s y ,s z ), then we have the Lambertian imaging equation model, the gray scale I i of P i can be written as:
[0000] I i =ρ i ( x, y ) n i ( x, y ) T ·s (1)
[0000] where i=1, 2, . . . , k, k is the number of pixels of a face image
p i is the surface reflection rate of Pi n T i indicates the surface vector of the point i · is the dot product operation x,y,z is the 3-D coordinate of Pi
[0032] It can be seen from the above equation that the facial image formation is related to the reflection and 3-D shape of the face surface, and the illumination. These are the three essential factors in the facial image formation process. The first two terms are related with the intrinsic characteristic of the face itself, and also the important information for face recognition; the last term, illumination, is the extrinsic factor, and also the primary factor which affects face recognition performance.
[0033] Although the light intensity ∥s∥ also affects the gray scale of facial images, this kind of influence can be adjusted using a simple linear transform. The top-most factor that affects the face recognition performance is the incidence angle of the light relative to the face surface vector. Assume that θ i is the angle between the incident light ray and the face surface vector at Pi (θ i ε [0, π]), the light intensity ∥s∥=1, then Equation (1) maybe expressed as follows:
[0000] I i =ρ i ( x, y )cos θ i (2)
[0000] where, i=1,2, . . . ,k; k is the number of pixels of a face image.
[0034] From equation (2), we can see that when is changes as a result of a change in the illumination direction, the facial image changes accordingly. It can also be illustrated by a correlation analysis: Given two facial images lighted from the left side and from the right side, respectively, the correlation coefficient of resulting images is generally a negative number; this means that the two images are completely different by the pixel values, even though of the same person.
[0035] In real applications, the environment lightings generally differ from place to place, and a face recognition system has to adapt to different environmental lightings. However, current face recognition technology mixes both intrinsic and extrinsic factors in the imaging and hence cannot adapt well to the environment This is why the best face recognition system can only achieve 50% accuracy (see also NIST 2002 Human Face Recognition Vendor Tests Evaluation Report (P. J. Phillips, P. Grother, R. J Micheals, D. M. Blackburn, E Tabassi, and J. M. Bone. March 2003).
[0036] Although there are many methods for compensation and normalization of illumination for face recognition, they are not very effective (see: P. N. Belhumeur, David J. Kriegman, “What is the set of Images of an Object Under All possible Lighting Conditions?”, IEEE conf. On Computer Vision and Pattern Recognition”, 1,996; Athinodoros S. Georghiades and Peter N. Belhumeur, “Illumination cone models for recognition under variable lighting: Faces”, CVPR, 1,998; Athinodoros S. Georghiades and Peter N. Belhumeur, ” From Few to many: Illumination cone models for face recognition under variable lighting and pose”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 23, No. 6, pp 643-660, 2,001; Amnon Shashua, And Tammy Riklin-Raviv, “The quotient image: Class-based re-rendering and recognition with varying illuminations”, Transactions on Pattern Analysis and Machine Intelligence, Vol. 23, No. 2, Pp 129-139, 2,001; T. Riklin-Raviv and A. Shashua. “The Quotient image: Class based recognition and synthesis under varying illumination” In Proceedings of the 1,999 Conference on Computer Vision and Pattern Recognition, Pages 566-571, Fort Collins, Colo., 1,999; Ravi Ramamoorthi, Pat Hanrahan, “On the relationship between radiance and irradiance: Determining the illumination from images of a convex Lambertian object”, J. Opt. Soc. Am., Vol. 18, No. 10, 2,001; Ravi Ramamoorthi, “Analytic PCA Construction for Theoretical Analysis of Lighting Variability in Images of a Lambertian Object”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 24, No. 10, 2002-10-21; Ravi Ramamoorthi and Pat Hanrahan, “An Efficient Representation for Irradiance Environment Maps”, SIGGRAPH 01, Pages 497-500, 2,001; Ronen Basri, David Jacobs, “Lambertian Reflectance and Linear Subspaces”, NEC Research Institute Technical Report 2000-172R; Ronen Basri and David Jacobs, Lambertian Reflectance and Linear Subspaces, IEEE Transactions on Pattern Analysis and Machine Intelligence, Forthcoming; Terence Sim, Takeo Kanade, “Illuminating the Face”, CMU-RI-TR-01-31, Sep. 28, 2001, etc) Among these methods, some requires 3-D modeling of faces, while some assumes known facial shapes. These limitations reduce the applicability. Moreover, the computational cost is very high.
[0037] There have been several face recognition patents, most of them using visible lights and for applications. One is Chinese patent ZL99117360.X. There, it is about how to implement the face recognition for access control and time attendance, without much attention paid to face image acquisition, and influence of skin complexion and light changes. The recognition accurate rate of this method under the lighting changes is still low. These limit its applications.
[0038] US Patent (US2001/0031072A1) disclosed a device using VISIBLE light sources to actively illuminate the face for face recognition. The device uses visible light as active light sources and hence inherits problems existing in current visible light image based face recognition; further, the visible light are intrusive to human eyes especially; this is especially true when the active lights should be strong enough to override environmental lightings, as is the case in US2001/0031072A1. That patent did not publicize how to use INVISIBLE infrared lights as active light sources to illuminate the face for facial image acquisition and recognition, nor is there any information there about how to setup infrared light sources and infrared filters for better face image acquisition and recognition.
[0039] There have also been iris recognition techniques for accurate biometric identification, such as used in Iridian Corporation's products. Disadvantages of such technology include complexity of iris image acquisition devices, and inconvenience of use. These limit the applications. Chinese patent ZL99110825.6 has also disclosed portable iris equipment. This equipment is limited by the similar disadvantages.
SUMMARY OF THE INVENTION
[0040] The object of the present invention is to provide a method and an apparatus for facial image acquisition and/or facial image recognition that can overcome one or more problems existing in the prior art, such as the accuracy of face recognition is deteriorated due to changes of environmental lightings. The present invention aims to solve the problems of prior art by using a non-intrusive and user-friendly means, and to achieve accurate and fast face recognition.
[0041] A further object of the present invention is to provide a method and an apparatus for face image acquisition, wherein an active near infrared (NIR) light is used to illuminate the face during the acquisition of face images. The method and apparatus can significantly reduce unfavorable influence caused by variable environmental lights.
[0042] A further object of the invention is to provide a method and an apparatus for face recognition in which eyes and face in NIR facial images acquired with illuminating of active NIR light are localized by detecting specular highlight reflections in eyes under illuminating of active lightings. The present method can lead to accurate and fast face recognition.
[0043] The present invention provides a face recognition method, comprising the following steps:
[0044] providing an active infrared light to illuminate a target face when a user approaches an image capturing unit, wherein said active infrared light mounted around lens of an image capturing unit is near infrared (NIR) radiation light sources in invisible light spectrum,
[0045] capturing a plurality of facial images from a target face illuminated by said active NIR light sources, and sending a NIR facial image to a data processing unit;
[0046] localizing said face and/or eyes of said face, and cropping a portion of said facial image from said NIR facial image by said data processing unit;
[0047] extracting facial feature from said portion of said facial image;
[0048] comparing facial feature with that of previously extracted and stored in a facial image database;
[0049] outputting a recognition result obtained from said comparing step.
[0050] Said face recognition method is provided, wherein a NIR filter is disposed on said image capturing unit for cutting off visible light radiation while allowing the NIR light radiation to pass through, so as to improve NIR face image acquisition.
[0051] Said face recognition method is provided, further comprising the steps of:
[0052] detecting specular highlight reflections in eyes in said NIR face image to localize eye positions and thereby localize said face.
[0053] Said face recognition method is provided, further comprising the steps of:
[0054] judging whether eyes and/or face is successfully localized after sending at least one facial image to a data processing unit; if yes, going forward to the next step of cropping a portion of said facial image, otherwise repeating the localizing step until eyes and/or face is successfully localized.
[0055] The present invention further provides a facial image acquisition method, comprising the steps of:
[0056] providing a plurality of active infrared lights to illuminate a target face, wherein said active infrared light mounted around lens of an image capturing unit is a near infrared (NIR) light in invisible spectrum;
[0057] providing an image capturing unit for capturing NIR images of said target face, and sending/storing said NIR face images to a data processing unit used for localizing and recognizing said target face;
[0058] wherein the total energy of said active NIR light plus said environmental lightings on entire area of said target face is greater than that of environmental lightings on entire area of said target face by at least twice times.
[0059] Said facial image acquisition method is provided, wherein a NIR filter is disposed on said image capturing unit for cutting off a visible light radiation while allowing a NIR light radiation to pass through, so as to improve NIR facial image acquisition.
[0060] The present invention further provides a facial image acquisition apparatus used for realizing a facial image acquisition method, comprising an active NIR light and an image capturing unit;
[0061] Said active NIR light is mounted around lens of said image capturing unit to illuminate a target face;
[0062] Said image capturing unit captures NIR images of said target face illuminated by said active NIR light, and sends said NIR images to a subsequent data processing unit.
[0063] Said facial image acquisition apparatus is provided, wherein a NIR filter is disposed on said image capturing unit for cutting off visible light radiation while allowing the NIR light radiation to pass through, so as to improve NIR face image acquisition.
[0064] Said facial image acquisition apparatus is provided, wherein the spectrum range of said active NIR light is between 740 nm-1700 nm; said NIR optical filter is an NIR optical coating or an NIR optical glass disposed on the surface or inside of said lens.
[0065] Said facial image acquisition apparatus is provided, wherein said active NIR light comprises a plurality of constant NIR lights, or a plurality of flash NIR lights, or the combination thereof.
[0066] Said facial image acquisition apparatus is provided, wherein the direction of said active NIR light is approximately parallel to axis of said lens.
[0067] Said facial image acquisition apparatus is provided, wherein the total energy of said active NIR light plus said environmental lightings on entire area of said target face is greater than that of environmental lightings on entire area of said target face by at least twice times.
[0068] Said facial image acquisition apparatus is provided, wherein said image capturing unit includes an NIR optical filter of band-wavelength-pass or long-wavelength-pass type.
[0069] The present invention further provides an facial image recognition apparatus used for realizing the above facial image recognition method, comprising an active infrared lighting, an image capturing unit and a data processing unit;
[0070] wherein said image capturing unit includes a lens; and said active infrared light comprises a plurality of active NIR lights used for illuminating a target face and mounted around said lens;
[0071] said image capturing unit is used for capturing facial images and sending at least one facial image to said data processing unit;
[0072] said data processing unit comprises a PC or an embedded processor in which image processing software is installed, used for receiving images from said image capturing unit and localizing eyes and face in said facial images, and extracting facial features in said localized facial area, and comparing the extracted features with that of previously stored in a facial image database.
[0073] Said facial image recognition apparatus is provided, wherein the spectrum range of said active NIR light is between 740 nm-1700 nm; said active NIR light comprises a plurality of constant NIR lights, or a plurality of flash NIR lights, or the combination thereof.
[0074] Said facial image recognition apparatus is provided, wherein the direction of said active NIR light is approximately parallel to axis of said lens.
[0075] Said facial image recognition apparatus is provided, wherein said image capturing unit includes an NIR optical filter of band-wavelength-pass or long-wavelength-pass type, and it is used to suppress visible lights while allowing NIR lights to pass through so as to achieve better NIR imaging effect.
[0076] Said facial image recognition apparatus is provided, wherein said data processing unit includes a means for detecting specular highlight reflection in each eyes in said NIR face image, it is used for localizing said eyes and face through localizing the positions of a highlight spots.
[0077] Said facial image recognition apparatus is provided, wherein there is a displaying device for displaying facial images, used for adjusting the position of the target face in vertical and horizontal directions; said displaying device is a mirror or an LCD (liquid crystal displace), mounted in such a way that its surface normal is co-axis to said lens.
[0078] Said facial image recognition apparatus is provided, wherein said active NIR light can be controlled by a power switch, a proximity sensor switch or an RFID controlled switch.
[0079] The present invention can effectively overcome a main problem existing in current visible light image based face recognition methods and systems that their accuracy drops because of the unfavorable impact of uncontrolled environmental lighting on facial images, and therefore can increase the recognition accuracy under uncontrolled environmental lighting.
[0080] The above advantages are realized by the invented NIR face image acquisition method and device wherein active NIR lights, strong enough to override environmental lighting, are used to illuminate the face during image capturing and at the same time visible lights in the uncontrolled environment are suppressed using an NIR optical filter. Therefore, the invention leads to stable imaging properties and hence high recognition accuracy under different lighting environments.
[0081] Moreover, the invented face image acquisition method and apparatus are user-friendly because the active NIR lights are in the invisible spectrum and cause no disturbance to human eyes.
[0082] The advantages are further realized by the method and apparatus for the NIR facial image acquisition and recognition, wherein highlight specularities in the eyes are located quickly and accurately. The facial feature template extracted based on accurate eye localization can represent the face accurately and hence lead to high recognition accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0083] FIG. 1 is a schematic diagram of a face recognition process;
[0084] FIG. 2 is a schematic flowchart diagram including both face recognition and enrollment processes;
[0085] FIG. 3 is a schematic illustration of a angle between an active light direction and camera lens axis;
[0086] FIG. 4 is a schematic illustration of an exemplar system that embodies a face recognition method in the present invention;
[0087] FIG. 4 a is a procedure for an embodiment of a face recognition method in FIG. 4 ;
[0088] FIG. 4 b is a diagram of an image acquisition and data processing modules for a system in FIG. 4 ;
[0089] FIG. 5 illustrates specular highlight reflections in eyes as reflection of active lighting on the eye surface;
[0090] FIG. 6 is a schematic diagram of an image capturing unit with active lights;
[0091] FIG. 7 is a schematic illustration of an access control system with the present invention of face recognition method incorporated;
[0092] FIG. 8 is a schematic illustration of an application of the present invention of face recognition method in machine readable travel document (MRTD);
[0093] FIG. 8 a is a schematic diagram of a face image acquisition in the face recognition based MRTD system in FIG. 8 ;
[0094] FIG. 8 b is a schematic diagram of a face recognition in a face recognition based MRTD system in FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0095] Detailed embodiments of the present invention are disclosed herein, with an illustrative drawings and an exemplar embodiment:
[0096] FIG. 4 discloses a preferred embodiment of an imaging system including image acquisition apparatus and/or image recognition apparatus according to the present invention, comprising active lights (LED) 421 , camera 422 , mirror (as an aid for face positioning) 423 , optical filter 424 , control switch 426 , data processing unit 430 , indicator LED, and power supply; an active light (LED) are evenly distributed around the camera 422 , and in the middle are the mirror 423 , the filter 424 and the camera 422 ; the mirror 423 is in the middle of the box of the imaging system, in the middle of the mirror is the filter 424 and the camera 422 ; the mirror 424 is inside or in frontal of the camera lens. The camera is connected electronically to the data processing unit. The control switch 426 is a infrared sensor switch, located in the lower part of the imaging box. an indicator illuminator is located above the camera 422 . The control switch 426 is connected to the active lights 421 , the camera 422 , illuminator 425 , and the power supply, when an infrared sensor in the switch 426 is triggered on, the switch 426 turns on the active lights 421 and the camera 422 , and the illuminator 425 turns red and blinking, meaning active lights and the camera are working; when the switch 426 turns off, the active lights 421 and the camera 422 stop, and the illuminator turns green, meaning standby.
[0097] First, the active lights 421 illuminate on the face area 410 , the camera 422 (which can be a web camera, a CCTV camera, or specialized infrared camera) captures an image of the face 410 ; the acquired image is transmitted to the data processing unit where face image recognition takes place.
[0098] FIG. 4 a reveals an embodiment of a face recognition apparatus given in the present invention, including the following steps:
[0099] Step 100 , start a face image acquisition system 420 ;
[0100] Step 110 , when human body approaches the system 420 , an infrared sensor is triggered on, and the active lights 421 illuminate the face area;
[0101] Step 120 , the camera 422 captures images of the face area illuminated by the active lights 421 ;
[0102] Step 130 , the camera 422 sends at least one face image to the data processing unit (such as a PC or an embedded data processor) 430 ;
[0103] Step 140 , the data processing unit 430 finds the face from the image and locates the positions of the eyes and/or face;
[0104] Step 150 , if the eye/face localization is successful, execute step 160 ; Otherwise, execute step 130 ;
[0105] Step 160 , crop the face area from the image;
[0106] Step 170 , extract facial feature template;
[0107] Step 180 , compare the extracted facial feature template with those stored in the face template database;
[0108] Step 190 , output recognition result.
[0109] In the above steps, the total energy of the active lighting 421 and the environmental lighting 427 on the face area is greater than twice that of environmental lighting. For example, if the strength of the environment lighting is 30 LUX, and that of the active lighting is 120 LUX then the strength of the active lighting is 4 times that of the environmental lighting.
[0110] In FIG. 4 and FIG. 4 a, the active lights 421 are NIR lights. Generally, active NIR lights in the present invention can include constant NIR lights, flash NIR lights, and/or a combination of them. The strength of the active NIR lights are much greater than that of environmental lights, hence the influence of the latter is much reduced. Similar effect could be achieved using visible lights.
[0111] However, because NIR lights are in the invisible spectrum, human eyes are insensitive to them, and the active infrared lights cause minimum disturbance to the human; meanwhile, an NIR optimal filter 412 can be added into the cameras, to cut off visible lights in the environmental lighting, so as to further reduce the influence of environmental lighting; therefore, NIR lights are the most suitable type of active lights.
[0112] In any embodiment of the present invention, whatever type of active lights are used to illuminate the face, the relative position between the active lights and the camera should be relatively fixed, and the angle between the direction of the active lighting and the axis of the camera lens should be in a sharp angle.
[0113] Refer to FIG. 4 . During the enrollment and recognition processes, the relative position between the face 410 and the camera 422 should not be changed, and the face plane and the axis of the camera 422 should be perpendicular to each other (i.e. the vector normal to the facial plane should be parallel to the axis of the camera); as such, the angle θ between the normal vector and the camera axis is relatively unchanged, and the resulting image is most stable under the active lighting.
[0114] When infrared lighting is used, an infrared optical filter can be mounted on the camera lens, so as to cut off the shorter wavelength visible lights, and to further reduce the influence of environmental lights. For the present invention, the preferred infrared lights are of near infrared in the wavelength range of 740 nm-1700 nm.
[0115] When an infrared optical filter is used, the filter can be either band-pass or long-pass type. For example, when the infrared lights are 850 nm LEDs, a band-pass filter could be chosen, such that it has the central wavelength of 850 nm to allow infrared ray of around 850 nm to pass while cutting of ray of wavelengths shorter than 800 nm and longer than 900 nm; or a long-pass filter could be chosen, such that it allows infrared ray of wavelength longer than 800 nm to pass, while cutting off ray of wavelengths shorter than 800 nm.
[0116] In FIG. 4 and FIG. 4 b, a data processing unit 430 in the present invention can be one of PC or an embedded data processor (of FIG. 4 b ).
[0117] In FIG. 4 b, to simplify the device, one could integrate all components into one circuit board and install the board in a casing box; the board circuits include the infrared sensor switch 426 , analog comparator 4223 , single-chip microcomputer 4222 , camera 422 (eg LogiTech Pro4000), control pecker 4221 , active lights 421 (near infrared LED array), and imbedded data processor 430 (eg MCS-51 series).
[0118] In FIG. 5 a and FIG. 5 b, one could make use of the specular highlight reflections in the eyes ( FIG. 5 a ) for the eye and face localization, which is an effective and computationally efficient means. The active infrared lights cause a specular highlight reflection in an eye, which can be seen in the face image. Therefore, one can detect the eyes and the face by detecting the highlights in the eyes. After the two highlights in the eyes are detected, one can locate the face area according to the geometric relationship between the two eyes and that between the eyes and the face. This enables fast and accurate face localization and much simplifies the face detection problem.
[0119] Refer to FIG. 3 again. Let the angle between the active light direction and the camera axis be θ, environmental light be S 1 and active light be S 2 , then the aformentioned equation (1) can be written as
[0000] I i =ρ i ( x, y ) n i ( x, y ) T ·( s 1 +s 2 ) (3)
[0000] where i=1,2, . . . ,k;
[0120] If the strength of the active lighting S 1 is much greater than that of the environmental lighting S 2 , i.e. ∥S 1 ∥>>∥S 2 ∥, then equation (3) can be approximated by:
[0000] I i ≈ρ i ( x, y ) n i ( x, y ) T ·S 1 (4)
[0000] where i=1,2, . . . ,k;
[0121] If in the process of face recognition, a further constraint is imposed, namely, the relative position between the face and the camera is un-changed and so is the angle between the facial surface normal and active light direction, then according to equation (4), the acquired image is determined by the intrinsic properties of the face (ie, facial surface albedo and facial surface normal), nearly regardless of environmental lighting. Facial images acquired in such as way is most stable and best for face recognition.
Applications
[0122] FIG. 6 and FIG. 7 disclose an embodiment of the present invention for face recognition based access control.
[0123] Refer to FIG. 7 . On a door 400 is an access controller 450 . The active light image acquisition system 420 transmits the face image to the data processing unit 430 , the data processing unit 430 makes a decision, and send the decision to the controller 450 to grant or deny the access.
[0124] In FIG. 6 and FIG. 7 , the imaging system 420 includes 8-12 infrared LEDs of wavelength 850 nm. The LEDs are mounted in frontal of the camera, in co-axis to the camera lens (the angle is 0 degree when the facial plane is perpendicular to the active light direction). With the 850 nm band-pass infrared filter 423 , the ray of 850 nm LEDs can pass through the filter, whereas ray of other wavelength is cut off. Or a long-pass filter may be used to allow ray of wavelength above 800 nm to pass while cutting off ray below 800 nm. The camera captures images of the face 410 , and sends them to the data processing unit detects the positions of the eyes and hence that of the face; the pose of the face is then corrected, and facial feature template extracted and compared; a recognition decision is made. The data processing unit then sends a signal to the controller according to the decision result to control the access of the door. In this embodiment the data processing unit is a desktop PC.
[0125] FIGS. 8 , 8 a and 8 b disclose another embodiment of the present invention for face biometric based machine readable travel document (MRTD). The first phase is face image enrollment, shown in FIG. 8 a, including the following major steps:
[0126] Step 300 , start an image enrollment system;
[0127] Step 310 , the passenger hands in the travel document 502 when the body approaches to within about 50 cm from the counter 500 . The infrared sensor switch turns on the active lights (near infrared LEDs) to illuminate the face area;
[0128] Step 320 , the passenger moves his head so that he can see his face in the middle of the mirror, so that the active light camera with an optical filter can take pictures of the face;
[0129] Step 330 , the camera captures at least one image and send it to the data processing unit (or a PC);
[0130] Step 340 , the data processing unit locates the two highlight spots from the image;
[0131] Step 350 , if two highlights are detected, execute S 360 , otherwise, execute S 330 ;
[0132] Step 360 , crop the face area from the image, based on the two detected highlight spots;
[0133] Step 370 , extract facial feature template(s);
[0134] Step 380 , store the extracted facial template(s).
[0135] FIG. 8 b discloses further details of face image acquisition and processing, including the following steps:
[0136] Step 200 , start a face recognition apparatus;
[0137] Step S 210 , the passenger hands in the travel document 502 when the body approaches to within about 50 cm from the counter 500 . The infrared sensor switch turns on the active lights (near infrared LEDs) to illuminate the face area;
[0138] Step 220 , the passenger moves his head so that he can see his face in the middle of the mirror, so that the active light camera with an optical filter can take pictures of the face;
[0139] Step 230 , the camera captures at least one image and send it to the data processing unit (or a PC);
[0140] Step 240 , the data processing unit locates the two highlight spots from the image;
[0141] Step 250 , if two highlights are detected, execute S 360 , otherwise, execute S 230 ;
[0142] Step 260 , crop the face area from the image, based on the two detected highlight spots;
[0143] Step 270 , extract facial feature template; Step S 280 , compare the extracted facial template with those stored in the database;
[0144] Step 290 , output recognition result.
[0145] In real applications, the face enrollment system and the face recognition system can be built into one combined system. The difference is that the latter does not include the enrollment phase. The custom inspector checks the documents against the enrolled passenger, associate the personal information with the enrolled facial image, and test whether the person can be verified his identity successfully by the system.
[0146] In the embodiment shown in FIG. 8 , the mirror can be replaced by an LCD display, so that the user can adjust the head position according to the feedback image shown on LCD. One may use a digital camera type device as an image capturing unit and also use it as the display.
[0147] Further, the imaging system of the present invention can be on a motion platform, to be an elevator-pan-tilt-zoom camera unit. Such a device can track the people, control the active lights, and capture face images. It also caters for people of different heights.
[0148] The present invention can enable face recognition in the complete darkness without environmental lighting.
[0149] The present has further advantages such as being highly accurate and stable, compact low in cost, autonomous, convenient to use in various applications and for installation and maintenance.
[0150] New characteristics and advantages of the invention covered by this document have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of parts, without exceeding the scope of the invention. The scope of the invention is, of course, defined in the language in which the appended claims are expressed.
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A method and apparatus for facial image acquisition and/or recognition used for person identification. In infrared face image acquisition, near infrared (NIR) images of a face are captured by an imaging unit with the face illuminated by active NIR lights; an NIR optical filter is used in the imaging unit to minimize visible lights in environments while allowing NIR lights to pass through. NIR face images thus acquired provides good image quality for the purpose of face recognition. In face recognition, eyes are localized in NIR face image(s) quickly and accurately by detecting specular highlight reflection in each eye, whereby face is then localized. The invention effectively problems caused by environmental lights, and leads to accurate and fast face recognition under variable lighting conditions. Moreover, the methods use a non-intrusive and user-friendly way of active lighting for face image acquisition and recognition because the NIR lights are in the invisible spectrum.
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CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable
FEDERALLY SPONSORED RESEARCH
Not Applicable
SEQUENCE LISTING OR PROGRAM
Not Applicable
BACKGROUND OF THE INVENTION
Field of Invention
This invention relates to power saws; specifically, power saws capable of making miter angle adjustments.
When trimming windows, doorways, and the like, there are typically two vertical pieces of trim boards, a horizontal trim board at the top, and for widows a couple of boards for the sill. Consider where the vertical pieces intersect the horizontal piece. At the intersection, each of the boards would have to be cut at a 45 degree angle. Professional carpenters want the boards to meet in such a manner that the vertical and horizontal boards look almost like one piece. This can be achieved by raising the board off of the miter saw base by a small amount when making the 45 degree cut. Typically, a professional carpenter would put a portion of a pencil or other similar item under the board to raise it slightly when making the 45 degree cut. Therefore, when the boards are put in place, this results in the horizontal board and vertical board contacting on an edge instead of complete contact on the adjoining surfaces. The edge is the edge that is visible when looking at the window framing. Because of this edge type contact, the boards look as if they are almost one board.
Miter saws have an adjustment that can produce the same type cut without using a pencil or similar item as an offset; however the adjustment is time consuming. On most miter saws, one would have to reach behind the saw and rotate a knob, tilt the saw head, and tighten the knob. For a professional carpenter, the time to do this is prohibitive. One saw manufacturer makes a saw which allows the adjustment to be made from the front of the saw. Even so, making the adjustment is time consuming. Additionally, because of the mass of the saw motor, making the adjustment quickly is awkward. Once the adjustment was made, it would be easy to not notice it, which would result in incorrect cuts when making trimming cuts other than the one described above, or worse yet when making framing cuts.
Objects and Advantages
This invention remedies the previously mentioned problems by providing a power saw with a miter angle adjustment specifically designed for trimming applications. The power saw with miter angle adjustment has the following advantages:
a) Makes an adjustment in the miter angle such that trimming pieces will adjoin on an edge. b) Provides a way to make the adjustment very quickly. c) Provides a way to remove the adjustment very quickly. d) Makes it clear whether the adjustment is or is not in place.
SUMMARY
In accordance with the present invention, a power saw with a miter angle adjustment.
DRAWINGS
Figures
FIG. 1 shows an isometric view of a miter saw with the offset that produces the miter angle adjustment.
FIG. 2 shows an isometric view of a table saw with the offset that produces the miter angle adjustment.
FIG. 3 shows an isometric view of a skill saw with the offset that produces the miter angle adjustment.
FIG. 4 shows an isometric view of a jig saw with the offset that produces the miter angle adjustment.
FIG. 5 shows an isometric view of a rack and pinion system that positions the offset.
FIG. 6 shows an isometric view of a bar sliding in a channel that positions the offset.
FIG. 7 shows a section view of the bar that slides in a channel.
FIG. 8 shows an isometric view of a bar that rotates into a channel to position the offset.
FIG. 9 shows a section view of the bar that rotates into a channel.
FIG. 10 shows a front view of a bar that rotates from underneath to position the offset.
FIG. 11 shows a left side view of a bar that rotates from underneath.
FIG. 12 shows a front view of a four bar mechanism that positions the offset where the mechanism is positioned via a thread rod.
FIG. 13 shows a front view of a four bar mechanism that positions the offset where the mechanism is positioned via a latch.
FIG. 14 shows a section view of a four bar mechanism that positions the offset where the mechanism is positioned via a latch.
FIG. 15 shows a 2 dimensional view of a rectangular-shaped rotating bar that positions the offset.
FIG. 16 shows the first section view of a rectangular-shaped rotating bar that positions the offset.
FIG. 17 shows the left side view of a rectangular-shaped rotating bar that positions the offset.
FIG. 18 shows a 2 dimensional view of a triangular-shaped rotating bar that positions the offset.
FIG. 19 shows the first section view of a triangular-shaped rotating bar that positions the offset.
FIG. 20 shows the left side view of a triangular-shaped rotating bar that positions the offset.
FIG. 21 shows a 2 dimensional view of a circular-shaped rotating bar that positions the offset.
FIG. 22 shows the first section view of a circular-shaped rotating bar that positions the offset.
FIG. 23 shows the left side view of a circular-shaped rotating bar that positions the offset.
FIG. 24 shows a 2 dimensional view of an oval-shaped rotating bar that positions the offset.
FIG. 25 shows the first section of an oval-shaped rotating bar that positions the offset.
FIG. 26 shows the left side view of an oval-shaped rotating bar that positions the offset.
FIG. 27 shows a 2 dimensional view of an attachment that repositions the offset.
FIG. 28 shows the left side view of an attachment that repositions the offset.
Reference Numerals
10 power saw
20 power saw motor
30 power saw blade
40 cutting material resting surface
50 offset
60 saw embodiment with rack and pinion offset positioning
70 rack
80 pinion
90 rack and pinion supporting structure
100 bracket
110 shaft
120 handle
130 sliding bar
140 channel for sliding bar
150 rotating bar
160 hinge
170 rotating bar channel
180 offset defining structure
190 hinge
200 spring
210 first positioning surface
220 second positioning surface
230 bar 1 of the four bar mechanism
240 bar 2 of the four bar mechanism
250 bar 3 of the four bar mechanism
260 bar 4 of the four bar mechanism
270 rotational joint
280 rotational joint with a threaded receptor
290 threaded rod
300 universal joint
310 structure positioning handle
320 handle
330 spring
340 restraining link
350 structure positioning latch
360 latch
365 latch keyhole
370 structure defining offset
380 shaft
390 shaft bearings
400 shaft restrainer
410 handle
420 spring
430 horizontal restraining member
440 vertical structural member
450 hinge
460 rectangular portion of shaft
470 —Offset prior to adding attachment that extends the offset
480 —Attachment for extending offset
490 —Screw
DETAILED DESCRIPTION
FIGS. 1 - 4 —Preferred Embodiment
This invention, at a minimum, applies to four types of saws as illustrated in the Figures listed below:
Miter Saw: FIG. 1 Table Saw: FIG. 2 Skill Saw: FIG. 3 Jig Saw: FIG. 4
In FIGS. 1 thru 4 the saw 10 has a motor 20 , a cutting blade 30 , a cutting material resting surface 40 , and an offset 50 , wherein the offset changes the cutting angle between the cutting blade 30 and the cutting material (not shown).
A preferred embodiment of the saw of the present invention is illustrated in FIG. 5 wherein the offset 50 is positioned via a rack 70 and a pinion 80 . The pinion 80 is connected to a shaft 110 that is positioned by a bracket 100 that is connected to the supporting structure 90 . The shaft 110 is connected to the handle 120 where rotation of the handle 120 rotates the shaft 110 which rotates the pinion 80 which moves the offset 50 relative to the cutting material resting surface 40 . This results in the offset 50 moving from a position below the cutting material resting surface 40 to a plurality of positions above the cutting material resting surface 40 .
FIGS. 6 - 7 —Alternate Embodiment
An alternate embodiment of the saw of the present invention is illustrated in FIG. 6 (isometric view) and FIG. 7 (section view), where the offset 50 is defined via a sliding bar 130 that slides in a channel 140 . Referring to FIG. 7 , notice that the bar 130 is held captive in the channel 140 due to the bar 130 and the channel 140 being wider at the innermost portions. The bar 130 can slide to a position that would engage the cutting material (not shown) to a position that would be clear of the cutting material.
FIGS. 8 - 9 —Alternate Embodiment
An alternate embodiment of the saw of the present invention is illustrated in FIG. 8 (isometric view) and FIG. 9 (section view), where the offset 50 is defined via a rotating bar 150 that rotates about a hinge 160 from a position in the channel 170 to a position (as represented by the dashed lines) clear of the cutting material resting surface 40 and thus clear of the cutting material (not shown). Referring to FIG. 9 , notice that the bar 150 can rotate into the channel 170 because the channel 170 and the bar 150 are shaped such that the bar 150 is not held captive by the channel 170 .
FIGS. 10 - 11 —Alternate Embodiment
An alternate embodiment of the saw of the present invention is illustrated in FIG. 10 (isometric view) and FIG. 11 (left view), where the offset 50 is defined via an offset defining structure 180 that rotates about a hinge 190 constrained either by the first positioning surface 210 or by the second positioning surface 220 , wherein the spring 200 holds the offset defining structure 180 on the positioning surfaces ( 210 , 220 ). When the offset defining structure 180 is positioned via the first positioning surface 210 , then the offset 50 would engage the cutting material (not shown). When the offset defining structure 180 is positioned via the second positioning surface 220 , then the offset 50 would not engage the cutting material.
FIG. 12 —Alternate Embodiment
An alternate embodiment of the saw of the present invention is illustrated in FIG. 12 (two dimensional view), where the offset 50 is positioned via a four bar mechanism. The first bar 230 is defined by the structure of the saw 10 , bar two 240 is connected on one end to bar one 230 and on the other end to bar three 250 , the other end of bar three 250 is connected to bar four 260 , and the other end of bar four 260 is connected to bar one 230 . The bars are connected via three rotational joints 270 and one rotational joint with a threaded receptor 280 . When the handle 320 is rotated, the universal joint 300 rotates, which rotates the threaded rod 290 which interfaces with the rotational joint with a threaded receptor 280 . This rotation results in the positioning of the four bar mechanism such that the offset 50 is positioned at a plurality of positions below the cutting material resting surface 40 to a plurality of positions above the cutting material resting surface 40 .
FIGS. 13 - 14 —Alternate Embodiment
An alternate embodiment of the saw of the present invention is illustrated in FIG. 13 (two dimensional view) and FIG. 14 (section view), where the offset 50 is positioned via a four bar mechanism. The first bar 230 is defined by the structure of the saw 10 , bar two 240 is connected on one end to bar 230 and on the other end to bar three 250 , the other end of bar three 250 is connected to bar four 260 , and the other end of bar four 260 is connected to bar one 230 . The bars are connected via four rotational joints 270 . The four bar mechanism is positioned via a latch 360 that is connected to a connecting link 340 that is attached to the four bar mechanism. When the latch 360 is rotated one way it slides through a key hole 370 in the structure 350 positioning the latch 360 . The latch 360 is restrained via a spring 330 . Depending on the engagement of the latch, the four bar mechanism is positioned such that the offset 50 is either above the cutting material resting surface 40 or below the cutting material resting surface 40 .
FIGS. 15 - 17 —Alternate Embodiment
An alternate embodiment of the saw of the present invention is illustrated in FIG. 15 (two dimensional view), FIG. 16 (section view) and FIG. 17 (left side view), where the offset 50 is positioned via a structural member 370 that is attached to the shaft 380 that is held in place via bearings 390 such that when the shaft 380 is rotated to one position, the offset 50 is above the cutting material resting surface 40 and when the shaft 380 is rotated to another position, the offset 50 is below the cutting material resting surface 40 . The shaft 380 would be held in position via the horizontal restraining member 430 interfacing with the rectangular portion 460 of the shaft 390 . The horizontal restraining member 430 pivots about the hinge 450 that is attached to the vertical structural member 440 . The spring 420 forces the horizontal restraining member 430 against the rectangular portion 460 of the shaft 390 which fixes the shaft 390 in place.
Operation— FIGS. 5-17
The operation of the saw of the present invention entails moving the offset 50 from a position below the cutting material resting surface 40 to a position above the cutting material resting surface 40 and vice versa via the mechanisms depicted in FIGS. 5-17 . The positioning of the offset affects the miter cutting angle. A carpenter might make several cuts where the change in the miter angle is needed, and then reposition the offset 50 such that no change in miter angle would occur.
ADVANTAGES
Based on the description above, the advantages of the saw of the present invention follow:
The power saw with miter angle adjustment has the following advantages:
a) This invention provides a way for a carpenter to quickly make a small miter angle change and to quickly remove the miter angle change. The change in miter angle is very precise (i.e. the same change every time). b) This invention makes it very clear that the miter angle adjustment is or is not in place. c) This invention greatly improves the ability of a professional carpenter to make consistent high quality cuts where the adjoining boards contact on edge. d) This invention does not impede in any way the normal use of the saw when the miter angle adjustment is not in place.
CONCLUSION, RAMIFICATIONS, AND SCOPE
This invention provides a saw that allows small adjustments in miter angles to be made quickly and precisely. Additionally, this invention makes it very clear whether the adjustment is or is not in place.
Although the description above contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, there are many ways to hold a four bar mechanism in place, most if not all of which would be applicable to this invention. Additionally, there are many ways to constrain a shaft that rotates as well as many ways to configure and implement a rack and pinion system. In general, there are many ways to position an offset that would be applicable to this invention. The important characterizing feature is that the offset is positioned.
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This specification discloses a mechanism that alters the cutting angle of a motorized miter saw. The cutting angle is altered by a mechanism that deploys a member from underneath the cutting material resting surface to above the cutting material resting surface. When deployed above the cutting material resting surface, the angle between the blade and cutting material is altered.
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BACKGROUND OF THE INVENTION
This invention relates to a device and method for shipping and dispensing precise amounts of dry particulate matter, such as fertilizer and pesticide products and such, into a liquid carrier stream.
Many useful agricultural chemicals and other such products are distributed in dry bulk form, either as powders, granules or small pellets, but are ultimately dissolved into a liquid carrier for application by spraying or irrigation equipment. Thus, a farmer will either purchase the chemicals dry, either in bags or bins, and mix them with water or other liquid carrier as needed, such as by pouring the chemicals and liquid carrier separately into a mixing tank, or will transport a tank to a chemical dealer who will dispense a pre-mixed solution into the tank. Unfortunately, environmental and safety regulations are typically more stringent regarding the transportation of chemicals in liquid form than in dry form.
Pneumatic systems have been developed for metering and transporting dry particulate matter in a stream of air, from a bulk storage bin to a mixing tank for subsequent mixing with a liquid. A useful example of such a system is a portable unit described in U.S. Pat. No. 5,803,673 and sold under the trade name “ACCUBIN”. The entire contents of the above-referenced patent are incorporated herein by reference as if fully set forth.
With many agricultural chemicals, prolonged exposure to high concentration of air-borne particulates is not desirable.
SUMMARY OF THE INVENTION
The invention features a means of transporting and storing a dry particulate material, and then dispensing controlled quantities of that material directly into a stream of liquid carrier. The invention is particularly applicable for use with agricultural chemicals, such as pesticides (e.g., herbicides), fertilizers and adjuvants. By “particulate form”, we mean to include powders, granular and pelletized materials that are not suspended in a liquid medium.
According to one aspect of the invention, a device is provided for dispensing precise amounts of dry particulate matter directly into a liquid carrier stream. The device includes a bin for holding a quantity of particulate matter, a conduit for transporting a stream of liquid carrier, and a meter connected to the bin for controllably releasing a desired amount of the particulate matter from the bin into the conduit while disallowing entry of the liquid carrier to the bin. The bin, conduit and meter are all mounted upon a portable structure for transportation with particulate matter in the bin.
In the embodiment discussed in more detail below, the meter is arranged at the bottom end of the bin, such that the particulate matter is fed into the meter by gravitational force.
In some embodiments, the meter includes a multi-vaned rotor constrained to rotate within a housing, with the rotor vanes defining between them discrete pockets of known volume. These pockets preferably each have a volume of less than about 30 cubic inches (500 cubic centimeters), more preferably less than about 25 cubic inches (400 cubic centimeters), and most preferably less than about 10 cubic inches (150 cubic centimeters).
In some cases, the meter also includes an electric drive motor for driving the rotor.
In presently preferred embodiments, the device includes a controller for controlling the number of revolutions of the motor, and, thereby, the volume of particulate matter released from the bin.
For supplying electrical power to the motor, an electrical storage battery may be mounted to the portable structure. In some instances, a battery charger may be adapted to receive power from an external source to recharge the battery. The battery may also be adapted to supply electrical power to the controller.
In some embodiments, an electronic programmable controller is included. The controller is adapted to operate the meter to release a desired volume of particulate matter, in accordance with operator input. This controller is preferably mounted upon the portable structure, but in other embodiments the controller may be a separable unit, with an electrical port provided on the inductor for attaching the remote electronic controller for controllably operating the meter.
In some instances, the controller is adapted to receive an operator input representing a desired weight of matter to be released and to calculate, based upon at least this input and a stored particulate matter density value, a corresponding volume of matter to be released.
When a preset amount of matter has been released, in some cases the controller is adapted to automatically stop releasing the particulate matter, while liquid carrier continues to flow along the conduit. Under such conditions, the controller is preferably adapted to alert an operator when the preset amount of particulate matter has been released.
In some embodiments, the conduit is adapted to apply a sub-atmospheric pressure to the released particulate matter, in the presence of an operative liquid carrier flow, to motivate the released matter into the conduit. This conduit may include an eductor, for example, which effectively forms a venturi. Such an eductor is preferably constructed to dissolve the particulate matter into the carrier liquid within the eductor, or as soon as possible thereafter. Preferably, the conduit is adapted to apply a vacuum of between about 0.5 and 6 pounds per square inch (3.4 and 41 kilo-pascals) below atmospheric pressure to the released particulate matter.
In some embodiments a check valve is disposed between the conduit and the meter. The check valve is adapted to be normally closed and to open when the sub-atmospheric pressure falls below a predetermined threshold, thereby applying the sub-atmospheric pressure to the downstream side of the meter. In some cases, a pressure switch responsive to this sub-atmospheric pressure is included, for enabling operation of the meter only in the presence of a desired amount of vacuum. In such cases, the pressure switch is located between the check valve and the meter.
Preferably, the bin comprises a hopper with sides sloped at an angle of between about 45 and 60 degrees from horizontal. It is also preferred that the hopper have an internal volume of between about 5 and 200 cubic feet (0.14 and 5.7 cubic meters.
In some cases, a vibrator is structurally connected to the bin and adapted to vibrate the bin during operation to assist flow of the particulate matter into the meter.
Preferably the portable structure has a base footprint sufficiently small to fit within a 4 foot by 8 foot (1.2 meter by 2.4 meter) rectangle. For example, one preferred embodiment has a base footprint of about 42 inches by 48 inches (1.0 meter by 1.2 meters).
According to another aspect of the invention, a method of dispensing precise amounts of dry particulate matter directly into a liquid carrier stream is provided. The method includes first connecting the conduit of the device of the invention, the bin of which contains particulate matter, to a source of liquid carrier; and then motivating a flow of the liquid carrier through the conduit, thereby dispensing a desired amount of the particulate matter from the bin of the device into the flow of liquid carrier.
In some cases, the particulate matter comprises an agricultural pesticide, fertilizer or adjuvant.
The liquid carrier may comprise water or a liquid fertilizer, for instance.
In some instances, the flow of liquid carrier is directed from the conduit of the device to a receptacle.
Where the device includes an electronic controller for controlling the meter of the device, the method may further include, prior to the step of motivating, entering a value into the controller representing a desired amount of particulate matter to be released. The method may also include, prior to the step of motivating, entering a value into the controller representing the density of the particulate matter to be released.
According to another aspect of the invention, a method of distributing agricultural chemicals in particulate form, to be mixed with a liquid carrier before use, is provided. The method includes the steps of:
(1) providing multiple devices constructed according to the invention, as described above; (2) distributing the devices, with corresponding quantities of agricultural chemicals, to individual end users for dispensing the agricultural chemicals into liquid carrier streams at remote locations; and then (3) accepting the devices as returned from the end users, after the end users have dispensed at least some of the distributed chemicals.
In some embodiments, the method also includes, before distributing each device, filling the bin of the device with the corresponding quantity of agricultural chemical; and then, after accepting the returned devices, refilling the bins of devices with additional agricultural chemicals.
By using an inductor constructed according to the invention, a dry chemical substance can be properly and accurately metered directly into a liquid carrier, without possibly harmful exposure to chemical dust and fumes. Additionally, transportation of pre-mixed liquid chemicals can be avoided, with the chemicals being transported all the way to their use site in dry form. Simple, automated operation at remote sites may be provided by a control system that is adapted to run on on-board batteries, with very little operator input. Other advantages and features will also be understood from the following description of embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a programmable, dry chemical inductor.
FIG. 2 shows the inductor being transported by truck.
FIGS. 3A and 3B are schematic side views of the inductor, with transparent side panels, to illustrate its internal components and structure.
FIG. 4A is a side view of the metering device, with the end caps of the meter housing transparent to show the internal rotor.
FIG. 4B is a cross-sectional view taken along line 4 B— 4 B in FIG. 4A , with the drive motor not sectioned.
FIG. 5 is an illustration of the control panel of the inductor.
FIG. 6 is an upper level functional schematic of the controller.
FIG. 7 illustrates a method of distributing agricultural chemicals.
DETAILED DESCRIPTION OF EMBODIMENTS
Referring first to FIG. 1 , a dry chemical inductor 10 is in the form of a box structure having side 12 and top 14 surfaces of sheet aluminum covering a steel frame 16 . Lifting brackets 18 at the four top corners of the frame are provided with lifting eyes 19 for hoisting the inductor by chain. Recesses 20 between the feet 22 of the frame provide clearance for fork lift tines. The feet are spaced so as to fit just inside of the lifting brackets of a lower inductor, with sufficient clearance for the lid of the lower inductor, for stable stacking. The inductor housing has an overall height “H” of 72 inches (1.83 meters), with a base footprint of about 42 by 48 inches (1.0 by 1.2 meters), the size of a standard shipping pallet, for efficient stacking on a standard flatbed truck. The height “H” of various embodiments will depend in part on the desired internal hopper volume. These dimensions provide for an internal hopper volume of 40 cubic feet (1.1 cubic meters), for example. Given the small size of the inductor, it can readily be loaded onto the bed of a standard pickup truck 24 for transportation, as illustrated in FIG. 2 . Other sizes of inductors will accommodate other hopper volumes.
Still referring to FIG. 1 , the top 14 of inductor 10 has an opening which is normally covered by a removable lid 26 . The opening may be of 22.5 inches (57 centimeters) in diameter, for example, similar to the diameter of a standard drum. Lid 26 is in the form of a cover 28 and rubber gasket 30 held in place by a clamp ring 32 to form a dust-free seal to reduce the change of operator exposure to airborne chemicals. Generally, such a seal is required by some presently existing safety, environmental and regulatory standards for shipping particulate chemicals.
As discussed further below, and shown in subsequent drawings, inductor 10 has an internal hopper containing a quantity of bulk material which is intended to be mixed with a liquid carrier for use. To dispense a desired quantity of the bulk material into a liquid carrier, the user must first hook up the carrier inlet port 34 to a liquid carrier source, such as a water pump (not shown), that is adapted to motivate a flow of liquid carrier into the inlet port of the inductor. The mixture outlet port 36 is connected to a flexible hose for directing the liquid carrier and entrained bulk material from the inductor to a desired destination, such as a spray tank or mixing tank (also not shown). In the illustrated embodiment, ports 34 and 36 are two-inch (roughly 5 centimeter) cam and groove quick-connect couplings, sized to permit a liquid carrier flow rate of at least about 350 gallons (1350 liters) per minute. A value representing the amount of bulk material to be released (the “setpoint”) is keyed into a control panel 38 , and a flow of liquid is started through the inductor. When the inductor has sensed the presence of sufficient carrier flow, it automatically meters into the flow the desired amount of bulk material, without letting the liquid carrier flow up into the internal hopper to wet any unreleased bulk material. When the desired amount of bulk material has been released into the flow of carrier liquid, inductor 10 automatically stops dispensing the bulk material and alerts the user that the setpoint has been reached. The user can then turn off the flow of carrier liquid, or let it continue to run through the inductor, such as to complete the filling of a spray tank and further dilute the mixture.
Referring to FIGS. 3A and 3B , a sealed hopper 40 is mounted within the outer structure of inductor 10 . Hopper 40 is shaped to promote gravitational feeding of bulk materials into the metering device 42 located at its lower end. We have determined that a wall slope angle “α” of between about 45 and 60 degrees will work for many particle shapes and sizes, 60 degrees being preferable for powders and other very fine particles. To assist with the flow of the bulk material into metering device 42 , an electric vibrator 44 , such as a model DC-300-24V available from Vibco, may be firmly attached to hopper 40 to vibrate the hopper and induce downward flow. Behind control panel 38 is a programmable electronic controller 46 that controls the operation of inductor 10 , including vibrator 44 and metering device 42 . Electric power is provided by a pair of 12 VDC, 17 amp-hour rechargeable batteries 48 , which provide enough power for about 4 hours of operation between charges with the vibrator running. An electrical charge port 50 is accessible from outside the inductor to recharge batteries 48 and/or power the inductor. Internal conduits hydraulically connect ports 34 and 36 through metering device 42 .
FIGS. 4A and 4B better illustrate the structural detail of metering device 42 . A ⅛ horsepower, 32 RPM, 24 VDC gearmotor 52 , such as model PR990235, available from Leeson, drives the multi-vaned rotor 54 of a bulk material transfer gate 56 , such as the airlock described in U.S. Pat. No. 5,803,673. Gate 56 has a rotationally molded polycarbonate housing 58 and end caps 60 , and an injection molded “DELRIN” rotor 54 with eight integrally molded vanes 62 that define, in cooperation with housing 58 and end caps 60 , eight discrete pockets 64 that transport bulk material from upper opening 66 , open to the hopper ( 40 , FIG. 3A ) to a conical vacuum chamber 68 defined within housing 58 below the rotor. The rotor is supported on integrally molded axial projections 100 protruding from each end of the rotor through corresponding holes in end caps 60 . An aluminum motor shaft receiver 102 , of hexagonal outer shape, is insert molded into one of projections 100 , and defines a keyed central hole for receiving the motor shaft which drives the rotor. PTFE-encapsulated neoprene O-rings 104 provide for dynamic sealing between rotor 54 and end caps 60 during operation. A running clearance of about 0.005 inch (0.13 millimeter) is provided axially between the rotor and each end cap, and radially between the rotor and housing 58 . We have found that this clearance results in acceptably low leakage about the vanes for most intended bulk materials and at operating vacuum pressures. At the highest point of their rotation, vanes 62 of rotor 54 extend above the upper flange 106 of the gate (i.e., into the hopper) a distance “d” of about 1.0 inch (25 millimeters), helping to avoid “bridging” of packable bulk materials just above the gate. In this embodiment, rotor 54 has an overall diameter of about 7 inches (18 centimeters) and a length of about 7 inches (18 centimeters).
All of pockets 64 are of similar volume. In this embodiment, each pocket 64 has a volume of about 25.92 cubic inches (425 cubic centimeters), which is effectively the “resolution” of the dispensing system. Of course, gates 56 defining discrete pockets of other shapes and volumes are considered within the scope of this invention. For example, pocket volumes as low as 3 cubic inches (50 cubic centimeters) provide even finer resolution. Ideally, each pocket is completely and sequentially filled with bulk material from opening 66 , and completely empties into vacuum chamber 68 . To help ensure complete pocket filling and emptying, motor 52 may be adapted to impart a vibration to gate 56 . For embodiments having a separate vibrator ( 44 , FIG. 3 A), the gate may be structurally coupled to the vibrator to enhance pocket filling. Rotor positional feedback to the controller is provided by rare earth magnets 69 embedded in the vanes of the rotor, which are sensed by a hall effect sensor 71 in the housing end cap adjacent the motor. Alternatively, motors 52 with built-in positional feedback systems may be employed. As rotor 54 rotates, pulses from hall effect sensor 71 inform the controller of the passage of each vane, and therefore of the emptying of each pocket. The controller monitors these pulses until it has determined that the desired number of pockets of material, as determined from operator input and known pocket volume, have been dispensed. Once the controller stops applying power to motor 52 , friction and internal damping generally cause the motor to coast only a few degrees before coming to a stop, providing for an accuracy of +/−1 pocket or better in the total amount released. Better accuracies may be provided by equipping the motor with braking means (not shown) to positively stop rotation of the rotor at a desired vane increment.
The inner side walls of vacuum chamber 68 are sloped at an angle “β” of about 76 degrees above horizontal, to aid in directing released bulk material downward into the inlet of a vacuum check valve 70 . We prefer an angle β of at least 70 degrees to overcome the tendency of some materials to adhere to the inner walls of housing 58 which, alternatively, may be of die-cast aluminum with an anodized PTFE inner surface.
Check valve 70 is attached, by air-tight connections, to both gate housing 68 and eductor 72 . Valve 70 contains a wafer 74 which is urged against a seat, toward gate 56 , by a preload extension spring 76 , thereby blocking flow between the gate and eductor. When a predetermined carrier flow rate through eductor 72 has been reached or exceeded, flowing from inlet 78 to outlet 80 , a reduction in absolute pressure is achieved below wafer 74 . When the vacuum below wafer 74 is sufficient, wafer 74 moves away from its seat and transmits this vacuum to chamber 68 . It is preferred that gate 56 not be operated to dispense materials before a vacuum pressure has been established in chamber 68 . In other words, it is preferable that a threshold flow rate through eductor 72 be established before motor 52 begins to rotator rotor 54 . To that end, a pressure switch 82 is responsive to vacuum pressure within chamber 68 and signals the controller when the pressure in chamber 68 is below a predetermined threshold. The controller does not activate motor 52 until such a signal is received, thus preventing material release until a sufficient flow rate of carrier liquid has opened check valve 70 . This also helps to reduce the amount of contamination of bulk material in the hopper if the system were operated with a failed, open check valve. Should the flow of carrier liquid suddenly stop, check valve 70 will automatically and rapidly close, thus preventing any substantial flow of carrier liquid up into chamber 68 . At the same time, switch 82 will detect the loss of vacuum and the controller will stop energizing motor 52 . Of course, insubstantial amounts of carrier vapor or droplets will occasionally pass through check valve 70 and enter chamber 68 , such as when flow through eductor 72 is abruptly stopped. Of this minor amount of leakage, a small amount of vapor may be vented through gate 56 and up into the hopper. Importantly, however, the combination of check valve 70 and gate 56 avoids any significant amount of carrier liquid, any amount which would cause detrimental contamination, packing or dissolution, to enter the hopper. Commercially available eductors 72 are available as models 2083-X from Mazzei (high flow, low vacuum), and “2-inch ELL” from Penberthy (low flow, high vacuum). For more controlled air flow through vacuum chamber 68 , such as to help keep released materials flowing through check valve 70 , a vacuum check valve (not shown) may be installed through the side wall of housing 58 , below gate 56 , to let in a controlled flow of air and regulate vacuum pressure.
Referring to FIG. 5 , control panel 38 has a digital display 84 for displaying textual information, and a keypad 86 for operator input. Besides a typical 10 number keys and a decimal key, keypad 84 includes a “STARTS/STOP” key 88 , an “ON/OFF” key 90 , an “ENTER” key 92 and a “RESET” key 94 . “ON/OFF” key 90 controls system power, as its name implies. Alter entering a setpoint, the operator pushes the “START/STOP” key 88 to begin automatic release of the material. During operation, pushing the “START/STOP” key 88 pauses the release of material and initiates an audible alarm and appropriate visual display indicating that release has been interrupted. “ENTER” key 92 is used for entering user input, such as data and passwords, and “RESET” key 94 is for acknowledging and resetting alarms or clearing keyed values. In addition, there are four additional functions performed by pushing various keys in combination with key “7”, sub-labelled “FUNCTION”. Holding key “7” while pushing key “1”, for example, displays the calibration factor (CF) for three seconds. This calibration factor represents the density of the bulk material, in pounds per pocket. Holding key “7” while pushing key “3”, displays current battery voltage (VDC). Holding key “7” while pushing either the “RESET” or “ENTER” keys will either raise or lower, respectively, the contrast of display 84 . If desired, a coaxial controller cable input jack 120 ( FIG. 1 ) may be provided for operation of the inductor from a pendant controller or keypad.
Three password levels are provided for various function authorizations. A typical user will be provided with a first level password which enables the entry of setpoints and very basic system operation. A second level password allows the user to change inventory parameters, calibration factors, or perform self-calibration. For self-calibration, the user will direct the system to dispense a given amount (e.g., weight) of material. The user then weighs the dispensed material with appropriate weighing means (not shown) and enters the weight of the material actually dispensed. The controller then adjusts its calibration factor accordingly. An example of changing inventory parameters is changing a value representing the total amount of bulk material presently contained within the hopper. For example, when filling the inductor with bulk material, a dealer may enter into the controller the total weight of material supplied. During operation, the controller continuously subtracts from this value the weight of material dispensed. When the controller determines that all of the material originally supplied has been dispersed (i.e., when the total weight register reads “0”), any further dispensing of material by the end user is disallowed. This safeguard is particularly important for enabling the dealer to reliably track the overall amount of material dispensed through the inductor, for example. A third level password authorizes more advanced adjustments, such as changing the motor speed, timer values or alarm points.
Referring to FIG. 6 , a programmable microprocessor 96 is programmed to perform all data manipulations in controller 46 . CPU 96 receives input from the vacuum sensor or switch 82 (FIG. 4 B), the vane-sensing hall effect sensor 71 (FIG. 4 B), keypad 86 and, in some embodiments, a serial port (e.g., port 120 in FIG. 1 ). Based upon these inputs, CPU 96 drives motor drive circuitry 97 to pulse-width modulate high side power to gate motor 52 ( FIG. 4B ) to drive the gate rotor and dispense product. At the same time, CPU 96 triggers a power switch 98 to turn on the vibrator, if so equipped. A 5V voltage regulator 99 steps battery voltage down to power the electronic controller components. Display 84 is a two row, 16 character per row, backlit LCD display via which the controller communicates visually with the operator. In addition, a buzzer 101 gives an audible alarm when triggered by the CPU.
In FIG. 7 , a method of distributing agricultural chemicals in particulate form includes distributing devices described herein, with quantities of agricultural chemicals, to individual end users 150 for dispensing the agricultural chemicals into liquid carrier streams at remote locations, and then accepting the devices as returned from the end users, after the end users have dispensed some of the distributed chemicals.
Other embodiments are also within the scope of the invention, although not illustrated in the drawings. For example, much smaller inductors may be produced for home gardening and landscaping applications, which are filled with dry chemicals at garden supply stores and then rented to homeowners or lawn care specialists. Such inductors may be attached to garden hoses for automatically dispensing selected rates of chemical into a monitored flow of water through the inductor. After use, the inductor may be returned to the dealer for cleaning and reuse, without the customer having ever been exposed to dry chemicals or had to either mix or transport liquid chemicals. Furthermore, inductors may be equipped with multiple, separate hoppers and metering devices, which may all feed a common eductor for instance, with a more sophisticated controller programmed to enable the operator to select chemical mix ratios, such as for customized fertilization. Such an inductor may be particularly useful to lawn care specialists, transported to each work site on the back of their equipment truck. Other embodiments will also be found to fall within the scope of the following claims.
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A device and method for dispensing precise amounts of dry particulate matter, such as agricultural chemicals, directly into a liquid carrier stream, such as a flow of water, and a method of employing such a device to distribute chemicals. The device includes a bin for holding a quantity of particulate matter, a conduit for transporting a stream of liquid carrier, and a meter at the bottom of the bin for controllably releasing a desired amount of the particulate matter from the bin into the conduit while disallowing entry of the liquid carrier to the bin. The bin, conduit and meter are all mounted upon a portable structure for transportation with particulate matter in the bin. The meter includes a multi-vaned rotor turned by a controlled motor, and defines discrete pockets of known volume. The operator simply connects the device to a flow of water and keys into the controller an amount of material to be released. The rotor releases the material into a chamber under vacuum pressure generated by a venturi, through a check valve, and into an eductor. Agricultural chemicals may be advantageously distributed to end users in particulate form, to be mixed with a liquid carrier at the work site, without possibly harmful exposure to chemical dust and fumes.
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FIELD OF THE INVENTION
This invention relates to a refreshment accommodating seat cushion and, more particularly, to a portable seat cushion that may be used to hold and transport snacks and beverages.
BACKGROUND OF THE INVENTION
Spectators attending sporting events, concerts and other stadium activities often partake in snacks, beverages and other refreshments. It is not uncommon for the spectator to leave his or her seat and travel to a centrally located vendor or concession stand to purchase such items. Transporting the refreshments back to the seat can be quite inconvenient and annoying. Obviously, the size and number of food and beverage items that one person can carry in his or her hands is limited. Some concession stands provide the fan or spectator with a flimsy cardboard holder. However, such holders are not very strong and are usually limited to carrying relatively few items. In a crowded stadium with narrow walkways, refreshments are commonly dropped and spilled.
Transporting refreshments from a vendor or concession stand back to one's seat is made even more difficult when the spectator is carrying a conventional portable seat cushion. Such cushions are often used to make the rigid seat surfaces normally found at sports arenas more comfortable. In crowded public settings, such as stadiums and arenas, the spectator may not be able to leave the seat cushion behind when he or she visits a concession stand because the cushion may be stolen. Accordingly, the spectator is forced to either leave the cushion with a companion or to carry the cushion to the vendor. If the person is required to transport both the cushion and refreshments back to his or her seat, there is a good chance that at least some item will spill. Moreover, when the spectator finally arrives at his seat, he usually has to either hold the refreshments in his hands or place them on his lap. In a crowded venue with limited seat size, there is again a good chance that food or drink will drop or spill. At present, there is no convenient and reliable means for transporting and holding the refreshments so that they are not spilled.
Not only do conventional seat cushions interfere with the transportation of refreshment items, they often exhibit a fairly thin, flimsy construction. As a result, relatively poor comfort and support are provided. Over time, the cushion breaks down and becomes even less supportive.
SUMMARY OF INVENTION
It is therefore an object of this invention to provide a sturdy and comfortable portable seat cushion that may be used as a tray for carrying and holding refreshments.
It is a further object of this invention to provide a refreshment accommodating seat cushion that is durable and resistant to food and drink stains.
It is a further object of this invention to provide a seat cushion apparatus that may carry a wide variety of attractive and entertaining logos, slogans and other indicia.
It is a further object of this invention to provide a refreshment accommodating seat cushion that is lightweight and easily transportable.
It is a further object of this invention to provide a portable seat cushion that provides improved support and comfort for a user who is required to sit for an extended period of time.
It is a further object of this invention to provide a refreshment accommodating seat cushion that securely holds a wide variety of food and beverage items so that they may be transported from a concession stand or vendor to a seat and held securely at the seat location without spilling.
This invention results from a realization that a portable seat cushion may be provided with a variety of pre-formed openings to accommodate food and drink beverage items. This invention results from the further realization that such a cushion will provide improved support and comfort and will comprise a stronger tray by employing a pair of padded sections on either side of a rigid central member. Only one of the padded sections includes openings for accommodating refreshment items. The other is preferably solid to provide improved comfort and support for the user.
This invention features a refreshment accommodating seat cushion apparatus including means defining a cushion having a pair of oppositely facing padded sections and a relatively rigid support element disposed within the cushion between the padded sections. There are receptacle means formed in the cushion through a first one of the padded sections for accommodating at least one refreshment container. The seat cushion is selectively engaged with a generally horizontal seat surface, such that the first padded section faces and touches the seat surface and the other padded section faces upwardly from the seat surface.
In a preferred embodiment each padded section includes a resilient substance. This may be composed of a closed cell foam element. The cushion may further include means defining a flexible covering formed over the foam elements. The flexible covering may comprise a plastic sheet-like material. The covering may alternatively comprise a fabric and a liquid resistant sheet formed over the fabric. The covering may include indicia printed on either the plastic or the fabric. The liquid resistant sheet may be transparent to permit viewing of indicia printed on the fabric. The flexible covering may also line the receptacles.
The support element may include a generally planar configuration. Preferably, the receptacle means are formed exclusively through the first padded section. Means defining a handle may be attached to the cushion. Such a handle is typically distinct from the cushion.
The seat cushion apparatus may also be made without a support element. In such cases the cushion is at least 21/2 inches and preferably approximately 3 inches thick. One or more of the receptacles is a minimum of 11/2 inches thick to accommodate a drink container. Preferably there is at least 1 inch of padded material beneath each receptacle.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Other objects, features and advantages will occur from the following description of preferred embodiments and the accompanying drawings, in which:
FIG. 1 is a perspective view of a refreshment accommodating seat cushion according to this invention;
FIG. 2 is a top plan view of the seat cushion illustrating the refreshment accommodating receptacles;
FIG. 3 is a bottom plan view of the cushion apparatus;
FIG. 4 is a sectional view taken along line 4--4 of FIG. 1.
FIG. 5 is a perspective view of the seat cushion apparatus as applied to a stadium seat/bench; and
FIG. 6 is a perspective view of the apparatus accommodating a variety of refreshment items.
There is shown in FIG. 1 a portable seat cushion 10 having a plurality of refreshment accommodating receptacles 12 formed therein. Cushion 10 includes a generally flat upper surface 14, shown alone in FIG. 2 and a flat lower surface 16, shown alone in FIG. 3. As depicted in FIGS. 1-3, the cushion includes a front edge 21, a pair of side edges 23 and 25 and a curved rearward edge 27. In alternative embodiments the cushion may have a perfectly square or rectangular configuration.
As shown in FIG. 1, cushion 10 comprises an inner resilient substance 18, which is typically a closed cell foam, such as urethane, or an analogous padded configuration.
As shown more particularly in FIG. 4, cushion 10 includes first foam section 20 and a distinct second foam section 22. A relatively rigid planar element 24 is interposed between foam sections 20 and 22 such that the foam sections face in generally opposite directions relative to support element 24. The support element may be composed of wood, plastic, Styrofoam TM or other materials that are rigid relative to the padded foam sections. In certain embodiments, foam sections 20 and 22 may be secured adhesively or otherwise to respective sides of element 24. Alternatively, however, a sheet-like material such as a fabric 26 covers element 24 and the padded foam sections are simply placed against the outer surface of fabric 26 without any adhesive.
A thin flexible covering 28, FIGS. 1 and 4, is formed over padded sections 20 and 22 and support element 24. Flexible covering 28 includes a plastic such as vinyl, which is stain resistant and easy to clean. Appropriate indicia may be printed on covering 28. For example, as illustrated in FIG. 6, the logo "Florida State Seminoles" is printed .on the lower surface 16 of cushion 10. In alternative versions, the flexible covering may include an inner fabric that is formed over foam 18 and an outer liquid resistant layer that is wrapped about the fabric. In certain embodiments, various types of indicia such as team names and/or logos may be printed on the inner fabric. In such embodiments, the outer liquid resistant layer preferably comprises a transparent plastic. As a result, the printed indicia is visible through plastic layer 32. At the same time, the liquid resistant plastic repels rain and drink spillage so that the cushion is easily cleaned and the life of the cushion is prolonged. In either embodiment, covering 28 is wrapped entirely about the interior padded sections 20 and 22 and the intermediate support element 24 arid are secured closed by various conventional means such as stitching or adhesives. The outer covering 28 holds the inner padded sections and support element securely in place to define the cushion apparatus.
Receptacles 12, shown in FIGS. 1, 2 and 4, comprise a central, generally X-shaped opening 36 and four cylindrical shaped openings 38, 40, 42 and 44. As best shown in FIG. 4, each of receptacles 12 is formed exclusively through padded section 20. Receptacles 38, 40, 42 and 44 are shaped for receiving beverage containers such as cups and cans. X-shaped receptacle 36 is designed for receiving various food and snack items, including popcorn, candy, hamburgers, hot dogs, etc. As shown in FIG. 2, receptacle 36 includes a relatively wide portion 50 and a relatively narrow portion 52. This provides varying widths so that various sizes of food containers may be snugly received within receptacle 36. As illustrated in FIGS. 1 and 4, the flexible covering 28 preferably lines the interior walls of receptacles 12 as well as the floors of the receptacles, which are defined by element 24. In alternative embodiments, the interior walls, are not covered and only planar surfaces 14 and 16 and edges 21, 23, 25 and 27 are lined.
As best shown in FIGS. 3 and 4, padded section 22 and the portion of covering 28 that extends over section 22 are solid and do not contain receptacles. This side 16 of cushion apparatus 10 serves as the surface of the seat cushion that faces upwardly to engage the user when the apparatus is placed on a seat. Improved support and comfort are achieved if no receptacles are formed in surface 16. However, in alternative embodiments, one or more receptacles may be formed in seat surface 16, as well.
Cushion 10 has an overall thickness of at least 21/2 inches and preferably approximately 3 inches. The padded portion 20 is preferably about 11/2-2 inches thick so that receptacles 12 have that depth. The underlying padded portion 22 has a preferred thickness of about 1-11/2 inches. As a result, apparatus 10 provides comfortable support for a spectator and exhibits improved rigidity when used as a tray. In certain embodiments the x-shaped receptacle is slightly shallower than the cup receptacles 38-44. The latter require greater depth to provide improved support for beverage containers.
As best shown in FIGS. 2 and 3, a handle 60 is secured to cushion 10. Handle 60 may comprise a plastic handle that is attached unitarily or otherwise to exterior plastic covering 32. Alternatively, handle 60 may be attached in other manners such as to the inner fabric 30 or to the inner resilient padding 18, shown in FIG. 1. Handle 60 permits cushion 10 to be conveniently transported to and from the location where it is to be used.
Cushion apparatus 10 is used to provide cushioning for seat S in the manner illustrated in FIG. 5. In particular, apparatus 10 is engaged with seat S such that the surface 14 (see FIG. 2) of apparatus 10 engages the rigid, generally horizontal seat surface 70 of seat S. Receptacles 12 face downwardly toward seat surface 70. Cushion surface 16 faces upwardly to provide the user with a cushioned seating surface. When the spectator sits upon cushion apparatus 10, the padded sections 20 and 22 intermediate support element 24 provide a supportive, yet cushioned seat surface that is comfortable for extended periods of time such as the duration of a sporting event, concert or stadium activity. As previously described, appropriate indicia is printed on the inner fabric covering 30 and is visible through the transparent outer sheet 32. Various other indicia may be carried on the reverse surface 14 and side edges of the cushion apparatus 10. Curved edge 27 is designed to mate with a curved seat back. However, the cushion works equally well with backless seating such as bleacher seats.
Apparatus 10 is converted into a refreshment accommodating tray, in the manner shown in FIG. 6, by simply lifting cushion apparatus 10 from the seat and inverting it so that receptacles 12 face upwardly. After the spectator has made purchases from a concession stand or vendor, various food and beverage items are placed in respective receptacles. For example, a cup 80 is snugly received in receptacle 40 and a can 82 is similarly received in receptacle 44. A bag of popcorn 84 is inserted into relatively wide section 50 of receptacle 36 and a box of candy 86 is held in relatively narrow section 52 of receptacle 36. It will be obvious that numerous other sizes, shapes and arrangements of liquid and food refreshments may be placed within receptacles 12. The resilient foam material that defines the receptacles provides for an adjustable snug fit so that many shapes and sizes of containers may be securely held in apparatus 10. After the refreshments are placed into receptacles 12, the user grasps the inverted cushion proximate its edges and carries it back to his seat.
Apparatus 10 serves as a strong and supportive tray which enables refreshment items to be carried back to the spectator's seat without spilling. The plastic covering resists stains and damage if some refreshment is accidentally spilled. After returning to his or her seat, the user may place the cushion/tray 10 on his or her lap or on an adjacent seat so that the refreshment items continued to be securely held. The rugged construction and, in particular, the use of internal support element 24 strengthens the cushion apparatus and helps prevent it from bending or collapsing, even under the weight of a number of refreshment items.
In alternative embodiments the support element 24 may be eliminated. In such cases a relatively thick or supportive cushioning material is critical. In these embodiments padded portions 20 and 22 are formed unitarily or glued together. The above described dimensional requirements are particularly important.
Although specific features of the invention are shown in some drawings and not others, this is for convenience only, as each feature may be combined with any or all of the other features in accordance with the invention. Other embodiments will occur to those skilled in the art and are within the following claims.
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A refreshment accommodating seat cushion apparatus is disclosed. A pair of oppositely facing padded sections are disposed about an intermediate relatively rigid support element. Receptacles are formed through one of the padded sections for accommodating, one refreshment container. The seat cushion selectively encases a generally horizontal seat surface such that a first padded section faces and touches the seat surface and the other padded section faces upwardly from the seat surface.
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BACKGROUND OF THE INVENTION
This invention relates to a valve arrangement comprising a distributor housing containing a distributor duct, an inlet duct leading into the distributor duct and at least two outlet ducts leading out of the distributor duct, and also containing valves associated with each respective outlet duct and which define the flow cross-section for a medium flowing through the inlet duct and distributor duct into the respective outlet ducts.
Schnaus et al., U.S. Pat. No. 5,269,348 discloses a valve arrangement of this type which comprises an inlet duct and at least two outlet ducts. A valve is associated with each outlet duct in order to distribute the medium fed through the inlet duct as needed to the outlet duct or ducts. In particular, this valve arrangement is used for a viscous medium, such as a polymer melt, in order to facilitate distribution to extruders, spinning devices or the like connected to the outlet ducts. This known valve arrangement comprises a central distributor housing with the above-mentioned ducts and the valves mounted on the housing. Each valve comprises a valve body which can be axially moved like a piston and which is arranged essentially radially with respect to the central distributor housing, whereby the mushroom-shaped valve body can also be moved back and forth in the above-mentioned radial direction. The drive for moving the valve body must be constructed to be relatively large since the pressure of the medium acts upon the valve body to its full extent. Thus, this valve arrangement has comparatively large dimensions. Special measures are required in order to avoid dead spaces in which portions of the medium may be trapped. In principle, the valve body therefore has a mushroom-shaped construction, and the medium flows around the valve body both when the valve is closed as well as when it is opened. Such a construction involves considerable additional expense.
German Patent No. DE 4,027,622 discloses a regulating flap valve which comprises a housing and a duct for the flowing medium. A flap disk is rotatably disposed on a shaft in the housing, the flap disk being integrated into the shaft and being situated with its contour inside the shaft. The flap disk is arranged in a central area of the duct, which area has a rectangular, especially a square, cross-sectional surface.
Austrian Patent Document No. AT 218,808 discloses a valve arrangement for pressure control lines of flow media, in which case several regulating flaps are provided, each of which is associated with a respective outlet duct. In the center of a distributor housing, a common cam plate is provided for actuating the individual regulating flaps. Each regulating flap is pivotably arranged laterally of the mouth of the respective outlet duct leading into the distributor duct and contains a projection which can be engaged by the cam plate in order to open the regulating flap. This valve arrangement contains dead spaces, primarily in the area of the bearings of the individual regulating flaps, in which a viscous medium, such as a polymer melt, may become trapped. Separate and mutually independent actuation of the individual regulating flaps by means of the central cam plate is not possible.
Finally, German Patent No. DE 169,268 discloses a three-way valve which has two outlet ducts, to each of which a respective regulating flap is assigned. The outlet ducts have a circular cross-section and the regulating flaps can be swivelled about a common axis of rotation. There is no distributor duct, and the regulating flaps open by swiveling into the end region of the inlet duct.
Despite the efforts of the prior art, there has remained a need for an improved valve arrangement of the aforedescribed type.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide an improved distributor valve with an inlet channel and a plurality of independently controllable outlet channels.
Another object of the invention is to provide a distributor valve which has a smaller overall size.
A further object of the invention is to provide a distributor valve which avoids dead spaces in which flowing medium may be come trapped.
It is also an object of the invention to provide a distributor valve which has an operationally reliable, compact construction.
Yet another object of the invention is to provide a distributor valve which has a low leak rate.
A still further object of the invention is to provide a distributor valve which is relatively simple to manufacture and assemble and which can be serviced without difficulty.
These and other objects of the invention have now been achieved by providing a valve arrangement comprising a distributor housing containing a distributor duct, an inlet duct leading into the distributor duct, and at least two outlet ducts leading out of the distributor duct; the housing further containing a valve integrated into the distributor housing and associated with each of the respective outlet ducts; each valve variably defining a flow cross-section for a medium flowing through the inlet duct and the distributor duct and out the respective outlet duct; each outlet duct having a rectangular cross-section where it opens into the distributor duct; each valve comprising a regulating flap arranged proximate where the respective outlet duct opens into the distributor duct, and each flap having an axis of rotation arranged such that the flap is situated partially in the distributor duct and partially in the respective outlet duct.
The valve arrangement of the invention is distinguished by a compact and operationally reliable construction. The common distributor housing not only contains the above-mentioned ducts but it simultaneously contains the valves of the at least two outlet ducts. The valves are integrated into the distributor housing which contains the bores for the valve flaps. The flaps as well as the associated central area of the duct are also situated in the common distributor housing. The outlet ducts have a rectangular, preferably square, cross-section where they open into the common distributor duct. The axes of rotation of the regulating flaps are arranged such that the regulating flaps are situated partially in the distributor duct and partially in the respective outlet ducts. Because of this construction, dead spaces in which the flowing medium may become trapped are avoided. When each of regulating flaps is in closed position, its surface associated with the distributor duct forms a virtually continuous continuation or extension of the outer wall of the distributor duct. Since the pressure of the medium acts upon all sides of the flaps, the valve drives may be dimensioned to be considerably smaller; which reduces the overall volume, the cost of material as well as the manufacturing costs. The distributor housing contains an annular distributor duct from which the at least two outlet ducts extend outwardly like the points of a star.
A deflecting element is preferably arranged in the center of the distributor duct. Between the mouth of the inlet duct and the exterior surface of the deflecting element, an annular channel is provided through which the incoming medium can flow into the distributor duct. The deflecting element is advantageously arranged opposite the inlet duct and preferably also projects part-way into the inlet duct, so that the tip of the deflecting element is positioned in the end region of the inlet duct. The medium, which flows through the inlet duct into the annular channel and from the thence into the annular distributor duct, takes on a flow component in the circumferential direction in the distributor duct. As a result, portions of the medium flowing through the valve arrangement are prevented in a particularly advantageous manner from remaining or becoming caught in the distributor duct. Because of this circumferential flow in the annular distributor duct, trapped or static accumulations of the medium will also be avoided even when only a single regulating flap is open. Preferably, the outlet ducts do not have a strict radially outward orientation relative to the center of the distributor duct, but instead the axes of the outlet ducts are offset angularly with respect to the center of the distributor duct. Because of this offset orientation of the outlet ducts, a circumferential flow component is imparted to the medium introduced through the inlet duct, and the formation of deposits or trapped residues of the flowing medium in the distributor duct is avoided.
The regulating flaps are arranged adjacent where the outlet ducts open into the central distributor duct. In relation to the center of the distributor duct, the axis of each flap, which extends through the center of the flap, is situated essentially on the same radius as the outer wall of the distributor duct. The projection of the regulating flap into a plane which extends through the pivot axis of the flap and through the linear contact surfaces between the flap and the duct walls, results in a rectangle, especially a square, which corresponds to the cross-sectional area of the outlet duct.
The inlet duct is advantageously arranged coaxially with respect to the center of the distributor duct and/or of the distributor housing. Opposite the mouth of the inlet duct, the distributor housing and the distributor duct are closed off by means of a closure member. A deflecting element is connected to the closure member. The deflecting element has a conical exterior contour and projects at least to the mouth of the inlet duct into the distributor duct.
In one preferred embodiment of the valve, the flap is constructed such that, in the central area, particularly of the outlet duct, it can be brought in contact with a contact surface in the closed position. Therefore, in the central area of the duct, the flap disk can no longer be rotated completely but can be pivoted only through a predetermined angular range. This assures a low leakage rate in view of different thermal coefficients of the valve housing, on the one hand, and the flap, on the other hand, without any danger that the flap will stick. The flap has a cross-sectional configuration which is similar to an ellipse, with the length of the major axis being larger than the width of the central duct area. The surfaces of the flap which contact the duct walls preferably have a crowned construction. Furthermore, the aforementioned major axis is larger than the diameter of the flap mounting shaft.
In a preferred embodiment, the shaft is surrounded by a centering bushing which rest with an inner base face or flange against the sides of the flap which project radially beyond the exterior surface of the shaft. At the side of the flap disk a seal is also provided between the centering bushing or its base face and the shaft; this seal also resting partially against the above-mentioned sides of the flap. The contact surface of the centering bushing or its inner base with the side surface of the regulating flap can be machined in a very precise manner and adjusted to the flap disk, which also assures a very low leakage at this location, particularly since the seal contacting the side of the flap prevents undesirable leakage of the medium. This measure also compensates in a particularly advantageous manner for the different thermal expansions of the flap and of the housing and assures low leakage of the valve even in case of comparatively large temperature differences.
Additional, preferred embodiments and refinements of the invention are described in the following specification.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments depicted in the accompanying drawings in which:
FIG. 1 is a sectional view of a valve arrangement according to the invention with three outlet ducts;
FIG. 2 is a sectional view taken along section line A--A of FIG. 1;
FIG. 3 is a view observed in the direction indicated by the arrow X in FIG. 2;
FIG. 4 is an enlarged detail view of the area designated IV in FIG. 1; and
FIG. 5 is an enlarged detail view of the area enclosed by the circle V in FIG. 2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a sectional view of a distributor housing 2 in which an annular distributor duct 4 is arranged. The distributor duct 4 is constructed as a cylindrical recess with a deflecting element 8 arranged at the center 6. In front of the plane of the drawing and perpendicular thereto, there is an inlet duct 46 which leads or opens into the distributor duct 4 and whose axis advantageously extends through the center 6. Three outlet ducts 11, 12 and 13 lead out of the distributor duct 4. Outside the housing 2, connection pieces 14, 15, 16 and/or tubes 18, 19, for the medium to be distributed are connected to the three outlet ducts 11, 12, 13. The outlet ducts 11, 12 and 13 are oriented asymmetrically with respect to the distributor duct 4, i.e. the axes 21, 22, 23 of the aforementioned outlet ducts 11, 12 and 13 do not extend through the center 6 of distributor duct 4. Instead, the axes 21, 22 and 23 form an obtuse angle 28 with respect to radial lines 24, 25 and 26, respectively. Because of this asymmetrical arrangement, when the outlet ducts 11, 12, 13 are completely or partially opened or closed, a circumferential component around the center 6 is imparted to the flow of medium. As a result, regardless of the respective positions of the individual valves of the outlet ducts 11, 12 and 13, which will be described hereinafter, trapped accumulations of medium in the distributor duct 4 or parts thereof are prevented in a particularly advantageous manner.
The valves associated with each of the outlet ducts 11, 12 and 13 are also integrated in the distributor housing 2. In FIG. 1, the regulating flaps 31, 32, 33 of these valves are shown in their closed positions. The arrows 34, 35 and 36 indicate the direction of the closing movement of the respective regulating flaps 31, 32 and 33. The axes 37, 38 and 39 of the respective regulating flaps 31, 32 and 33 are oriented perpendicularly with respect to the plane of the drawing and are situated at least approximately at the same radius 40 as the outer wall 42 of the distributor duct 4 which is cylindrical at least in the area of the regulating flaps. This assures that when the regulating flaps 31, 32 and 33 are in their closed positions, and are thereby situated partly in the distributor duct 4 and partly in the respective outlet ducts 11, 12 and 13, there will not be any dead spaces between the respective regulating flaps 31, 32 and 33 and the outer wall 42 of the distributor duct 4. The flaps 31, 32 and 33 are components of respective shafts 44, each of which is surrounded by a centering bushing 56 which will be described in further detail hereinafter. A shaft seal 62 is provided between the centering bushing 56 and the shaft 44. The shaft seal 62 may be made, for example, of polyimide or a comparable material.
The sectional view of FIG. 2 shows the regulating flap valve integrated in the distributor housing 2 for outlet duct 13 with its regulating flap 33 which is an integral component of a shaft 44. The axis of rotation 39 of the shaft 44 which carries flap 33 extends parallel to the inlet duct 46 whose axis 48 extends through the center 6 of distributor duct 4. Inlet duct 46 opens into the coaxial distributor duct 4 which is closed at its other side by means of a closure member 50 secured to the distributor housing 2. A deflector element 8 is attached to the closure member 50 inside the distributor duct 4. In the embodiment shown, the deflecting element 8 has a conical exterior surface 52 with a rounded tip which extends toward the mouth of inlet duct 46. Thus an annular passageway 53 is formed between the deflecting element 8 and a preferably rounded transition area 51 joining the inlet duct 46 to the annular distributor duct 4. The medium flows through this annular passageway 53 directly into the distributor duct 4. The closure member 50 can easily be removed so that the interior of the distributor housing 2 can be accessed without difficulty for servicing, cleaning, etc.
At least in the area of the regulating flap 33, where outlet duct 13 opens into the distributor duct 4, the outlet duct has a rectangular, preferably square, cross-section. The following description regarding the regulating flap valve with regulating flap 33 apply in a corresponding manner to the two other regulating flap valves for the other two outlet ducts. The distributor housing 2 contains a through bore 54 for the shaft 44 with the regulating flap 33. Through bore 54 extends perpendicularly to the axis 23 of the outlet duct 13 and is advantageously arranged essentially parallel to the axis 48 of the inlet duct 46. On both sides of the outlet duct 13, a centering bushing 56 respectively is inserted into the through bore 54, the inner base face 58 of the centering bushing 56 reaching directly to and immediately adjoining the outlet duct 13. Relative to the interior wall of the centering bushing 56, the inner base 58 is lengthened in the direction of the shaft 44 to form a flange which has an inside diameter only slightly larger than the outside diameter of the shaft 44. By means of an inner bushing 60 which surrounds the shaft 44 and can be axially displaced inside the centering bushing 56 in the direction of the axis of rotation 39, shaft seals 62 are pressed against the aforementioned inner base face 58 of the centering bushing 56. The inner bushing 60 is biased axially by means of springs 64 so that the shaft seal 62 assures an operationally reliable sealing. The springs 64 may be compressed by means of an adjusting plate 66 which is movably secured to the distributor housing 2. An annular body 68 is also connected to the distributor housing 2 by means of screws 70. By means of the annular body 68, a seal 72 arranged in the area of the exterior surface of the centering bushing 56 is compressed and/or fixed against the distributor housing 2.
FIG. 3 is a partial view of the valve arrangement observed in the direction indicated by the arrow X in FIG. 2 in which the square cross-section of the outlet duct 13 in the area of the regulating flap is easily visible. As mentioned above, the adjusting plate 66 is connected to the housing 2 by means of screws 74, 75 so that the springs 64 can be prestressed as required. One end of the shaft 44 is provided with a connection piece 76, which in this case is formed in particular as a square key in order to facilitate connection of an actuating drive.
FIG. 4 illustrates in detail another specific alternative embodiment of the invention. This embodiment is independent of the above-described multiple-valve arrangement and comprises a regulating flap valve in a single continuous duct 80, shown in the drawing by broken lines. In this particular alternative embodiment, the aforedescribed outlet duct 13 constitutes a part of the continuous duct 80 which, in the vicinity of the regulating flap 33, has a central area with a rectangular, especially square, cross-section as explained above. In this generalized case, the duct 80, including the outlet duct 13, is a component of a valve housing instead of a distributor housing 2. In the central area with the regulating flap 33, the duct 80 has a width 82 which is larger than the diameter 84 of the shaft 44. As can be seen, the regulating flap 33 has a cross-section which is similar to an ellipse; the exterior surfaces 86, 87 preferably forming portions of cylindrical surfaces. The regulating flap 33 has a major axis with a length 88 or maximum diameter which is larger than the width 82 of the duct 13 or 80. As shown, in the shown closed position, the regulating flap 33 is positioned with contact surfaces 90, 91 resting against the opposite inside walls 92, 93 of the duct 80. In order to prevent jamming, while at the same time assuring optimum sealing, the contact surfaces advantageously have a slightly crowned construction. It should be understood that the duct 80 does not need to have the rectangular, especially square, cross-section along its entire length, but instead at a certain distance from the regulating flap, separated, for example, by an approximately conical transition area 94 which can be seen in the drawing, it may have a cylindrical inner contour.
FIG. 5 is an enlarged detail view of a circular region V shown in FIG. 2 corresponding to a sectional plane taken along section line A--A of FIG. 1. The centering bushing 56 arranged in the through bore 54 of the housing 2 rests with its inner base face 58 partially against the side surface 96 of the regulating flap 33. The base face 58 has an inside diameter 98 which is larger by a predetermined amount than the outside diameter of the shaft 44. As shown in the drawing, a part 100 of the shaft seal 62 extends through the gap between the base flange 58 and the shaft 44 and rests against the side surface 96 of the regulating flap 33. This assures a good sealing effect at side surface 96. In addition, the centering bushing 56 assures that the regulating flap 33 will have a defined axial alignment, and the contact of the base face. 58 of bushing 56 with the side surface 96 of the flap 33 acts to impede undesired leakage when regulating flap 33 is in its closed position. The side contact surface 96 and the adjacent base face 58 may be manufactured with great precision so that there is virtually no annular gap between them through which leakage may occur. Furthermore, it should be emphasized that the maximum diameter of the regulating flap 33 or the length 88 of the major axis is smaller than the inside diameter of the through bore 54 of the housing 2, so that the shaft 44 with the regulating flap 33 thereon can be readily inserted through the bore into the housing 2.
The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include everything within the scope of the appended claims and equivalents thereof.
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A valve arrangement including a distributor housing (2) with a distributor duct (4), an inlet duct (46) which leads into the distributor duct (4), at least two outlet ducts (11, 12, 13) which lead out of the distributor duct (4), and a value associated with eac;h outlet duct. The values are integrated into the distributor housing (2) and have regulating flaps (31, 32, 33) whose axes of rotation (37, 38, 39) are arranged such that the flaps are situated partially in the distributor duct (4) and partially in the associated outlet duct (11, 12, 13). This construction reduces the overall size of the valve arrangement and eliminates dead spaces in which medium flowing through the valve arrangement could become trapped.
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CROSS REFERENCES TO RELATED APPLICATIONS
None.
BACKGROUND OF THE INVENTION
a. Field of the Invention
The invention relates to devices related to devices for the removal and grading of snow, gravel and the like. In particular, the invention relates to devices intended to be removably attached to light utility vehicles, including pickups, suburbans, tahoes, and the like for removal and grading of snow and gravel.
b. Description of the Prior Art
Devices for grading and removing snow are well known. There are two basic types of snowplow devices:
1. Devices intended to be mounted on the front of a vehicle, such as U.S. Pat. No. Re. 35,700 to Watson, et al., for a Removable Snowplow Assembly With Pivotable Lift Stand; and
2. Devices intended to be mounted on the rear of a vehicle such as U.S. Pat. No. 5,595,007 to Biance, for a Trailer-Type Snowplow.
There are advantages and disadvantages to both types of devices. For example, the devices mounted on the front of a vehicle tend to decrease the chances of the vehicle becoming stuck in the snow or gravel. That is because the snow or gravel is moved before the wheels contact the surface. That is, the wheels are rolling on ground that has already been plowed. Further, the front-mounted devices allow a driver of the vehicle to more easily keep an eye on the plowing operation. In addition, the front-mounted devices allow a user to more easily stack or pile-up the material being moved.
Nevertheless, despite their advantages, there are also disadvantages to the front-mounted types of devices. For example, most vehicles do not have attached thereto the necessary hardware for mounting a front-mounted snowplow.
Therefore, there are also a plurality of designs for rear-mounted snowplows. U.S. Pat. No. 5,595,007 to Biance, discloses such a trailer-type snowplow. Biance utilizes a "receiver hitch"--receiver hitch type mounting device. That is, the snowplow mechanism has a male portion adapted to be removably be received within a female portion of a bracket mounted to the vehicle. A pin passes through the male portion of the bracket and the female portion of the snowplow fixing them in relation to one another. The snowplow can easily be removed from t he vehicle by removing the bland sliding the male portion of the snowplow out of the female portion of the bracket. The advantages of the Biance device is that a user can easily remove the snowplow from the vehicle without unsightly and space consuming hardware being left thereon. Prior are devices required a user to leave a mounting bracket permanently attached to the vehicle. This mounting bracket typically detached to the bumper and other points on the vehicle, taking up space and detracting from the appearance of the vehicle.
Another type of rear-mounted snowplow apparatus is disclosed in U.S. Pat. No. 5,265,355 to Daniels. Daniels device is a three-point mounted snowplow. That is, there is an attachment at a center of a rear bumper and on either end of a rear bumper of a vehicle. Daniels discloses a box-type blade device. It has a means for raising and lowering the blade (as did Biance). The device disclosed by Daniels is extremely heavy and relatively expensive to manufacture. The angle of the blade with respect to the rear bumper of the vehicle is fixed in the Daniels device. That is, there is no way to angle the blade so as to move it to one side of the vehicle or another.
Given the currently available and known devices, there is a need for a plow device which is extremely simple and inexpensive to manufacture. There is also a need for a device which can be attached to existing trailer hitches on vehicles. Specifically, there is a need for a snowplow which attaches to standard trailer-towing balls on the bumpers of many vehicles.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types of devices for the removal and grading of snow, gravel and the like, it is an object of the invention to provide an apparatus which overcomes the various disadvantages of the prior art.
It is therefore an object of the invention to provide a snowplow which has a connection means capable of being attached to trailer-towing balls on the rear bumper of a vehicle.
It is a further object of the invention to provide a simple means of transporting the plow when a user does not desire for the plow to be in contact with the ground.
It is a also an object of the invention to provide a simple means for adjusting the angle of the blade with respect to the rear bumper of a vehicle.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in this application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. Additional benefits and advantages of the present invention will become apparent in those skilled in the art to which the present invention relates from the subsequent description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientist, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and the objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 is a top view of the trailer-type floating snowplow.
FIG. 2 is a side view of the trailer-type floating snowplow.
FIG. 3 is a front view of the trailer-type floating snowplow.
FIG. 4 is a rear view of the trailer-type floating snowplow.
FIG. 5 is a detailed side view of an adjustable wheel mechanism.
FIG. 6 is a bottom view of the same adjustable wheel mechanism shown in FIG. 5.
FIG. 7 is a top view of one configuration of the trailer-type floating snowplow attached to a rear bumper of a vehicle.
FIG. 8 is a side view of a second embodiment of the trailer-type floating snowplow attached to a vehicle with the scraping surface in contact with the ground.
FIG. 9 is a side view of the same embodiment of the trailer-type floating snowplow with the fixed wheels in contact with the ground and the offset hitch plate attached to the lower ball of the reversible hitch.
FIG. 10 is a detailed side view, partially in section, of the reversible hitch and offset hitch plate.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, where like numerals represent like or parts, an apparatus 10 incorporating the principles of the present invention is generally illustrated in the figures. FIG. 1 shows the apparatus 10 in a first embodiment. The embodiment shown if FIG. 1 is the same as the embodiment shown in FIGS. 2 through 7. An alternative embodiment of the invention is shown in FIGS. 8 through 10.
The embodiment shown in FIGS. 1 through 7 will be detailed first followed by a description of the embodiment shown in FIGS. 8 through 10.
The trailer-type floating snowplow 10 holds a blade 12 for scraping snow, gravel, and the like. Preferably, the blade is made out of a hardened steel material, which is durable yet tough enough so that not to be brittle. The blade may be either straight or slightly concave with the concave portion facing the vehicle facing behind which it is being towed. As shown in FIGS. 1 through 7, the blade 12 is straight, while the blade 12 is shown as curved in FIGS. 8 and 9. The blade has a front 14 which faces the vehicle behind which it is being towed and a back 16 which faces away from the vehicle. A scraping surface 18 is defined along one of the long edges of the blade 12. A first hitch bar 24 is attached to the blade 12 by a first bar connection means 30 adjacent to a first end 20 of the blade. A second hitch bar 26 is attached to the blade 12 by a second bar connection means 32 at or near a center point between the first end 20 and second end 22 of the blade 12. The first and second hitch bars combined with the blade define a triangular shape. That is, the first and second hitch bars come together at a distal end. A crossbar 28 is disposed between the first and second hitch bars 24 and 26 somewhere between the blade and a point where they come together. The crossbar 28 provides additional stability to the first hitch bar 24 and the second hitch bar 26. At a point where the first hitch bar and the second hitch bar 24 and 26 come together, they are attached to a hitch plate 34. A releasable hitch 36 is also attached to the hitch plate 34. The releasable hitch is one of the commonly commercially available hitch means for engaging a ball-type hitch on a vehicle bumper. A multiplicity of places are available to accomplish this objective, and one skilled in the art would be aware of these types of devices for engaging a ball-type hitch. The releasable hitch 36 is shown attached to a first connection point 70 in FIG. 7. The first connection point 70 is preferably a ball-type hitch attached either directly to a bumper of a vehicle or to a receiver-type apparatus with a removable receiver hitch, and these devices are well known.
In the first embodiment of the plow as shown in FIGS. 1 through 7, two wheels are attached to the blade adjacent to the scraping surface. The first wheel 38 detaches by means of a first wheel adjustment means 40. Similarly, a second wheel 42 is attached by means of a second wheel adjustment means 44. The attachment of the wheels is shown in detail in FIGS. 5 and 6. FIG. 5 is a side view of the wheel adjusting means 44. For each wheel, two Z-shaped members, 52a and 52b, are attached to the blade 12 by bolts 54. At least two bolts, 54a and 54b, are attached to each Z-shaped member 52. In cooperation, the two Z-shaped members for each wheel, 52a and 52b, define a channel for slidingly receiving a sliding member 56. The sliding member has attached to it two side plates, 58a and 58b. The side plates, 58a and 58b, angle downwardly and away from Z-shaped members, 52a and 52b. An axle 60 passes through the side plates, 58a and 58b, upon which is mounted a wheel 38 or 42. Adjusting holes 64 are defined through the two Z-shaped members. The adjusting holes 64 are in linear alignment, so that a removable locking pin 62 may pass there through. A corresponding hole defined in the sliding member 56 (hole now shown) so that when the removable locking pen 62 is passed through the adjusting hole 64, it fixes the sliding member 56 into place. FIG. 6 shows the sliding member 56 and the associated side plates 58 and wheels 38 and 42 in a first position, P1, and a second position in outline, P2. In position P1, the removable locking pin 62, is inserted through hole 64a. By contract, the sliding member 56 is slid upwardly in the channel defined by the two Z-shaped members, 52a and 52b, to a second position as shown by P2. At position P2, the removable locking pin 62 passes through hole 64b to fix the wheel in place. It will be noted that at position P1, the wheel is in contact with the material to be graded and/or the roadway. Whereas in position P2, the wheels, 38 and 42, are above the scraping surface 18 of the blade 12.
A chain 46 is attached to the blade 12 near the second end 22. The chain is attached via a chain attachment means 48. Basically, the chain attachment means is a bracket which is drilled through the blade with bolts on the back side. The chain 46 is then attached to the chain attachment means 48. The chain is of a slightly longer length than the first and second bar connection means. At an end opposite of the point where it connects to the chain attachment means 48, an adjustable chain loop 50 is defined. The adjustable chain loop 50 is created by taking a portion of the chain's 46 length and doubling it back. A mechanism is then inserted between two of the chain links to create a loop. This mechanism must be releasable (such as a bolt nut which can be tightened or loosened). The chain 46 is used to fix the angle of the blade relatively to the rear bumper of a vehicle. This principle is illustrated in FIG. 7. As shown, the adjustable chain loop 50 is looped around a second connection point 72. The releasable hitch 36 is attached to a first connection point 70. Both connection points are fixed on a bumper 68 of a vehicle 66. Thus the blade is attached to the vehicle 66 at a fixed angle. If the adjustable chain loop 50 is used to shorten the chain 46, the second end 22 of the blade 12 is moved closer towards the bumper 68 of the vehicle 66. Conversely, if the adjustable chain loop 50 is used to shorten the chain 46, the second end 22 is moved farther away from the bumper 68.
An alternative embodiment of the plow 10 is shown in FIGS. 8 through 10. The alternative embodiment in FIGS. 8 through 10 is simpler than the embodiment shown in FIGS. 1 through 7. It incorporates a reversible hitch 74. The reversible hitch 74 has an upper ball 76 and a lower ball 78. The reversible hitch may be either mounted to the bumper or may be a receiver-type hitch which is inserted into a receiver just below the bumper of the vehicle. The means of mounting the reversible hitch is immaterial to the invention. However, if a receiver-type mechanism is used, it is not necessary to have both an upper ball 76 and a lower ball 78. Where a receiver-type hitch is used, the receiver can be removed and turned 180° to rotate the ball to either an up position or a down position. An offset hitch plate 80 is designed to operate with the reversible hitch 74. The offset hitch plate maintains the first and second hitch bars is a position substantially parallel with the ground whether the releasable hitch 36 is engaged with the upper ball 76 or the lower ball 78. FIG. 8 shows the releasable hitch engaged with the upper ball 76. FIG. 9 shows the releasable hitch 36 engaged with the lower ball 78. This embodiment incorporates a fixed wheel 82. Whereas the other embodiment of the plow incorporated a wheel adjustment means 40 and 44. The alternative embodiment discussed now does not allow for adjustment of the wheels' 82 position. FIG. 10 is a partial cross-sectional detailed view of the reversible hitch 74, including the upper ball 76, the lower ball 78, and the releasable hitch 36, along with the offset hitch plate 80.
OPERATION OF APPARATUS
In operation, the plow 10 typically is attached to a ball-type connection means on a rear bumper of a vehicle. In a first embodiment of the invention, the user attaches the releasable hitch 36 to the ball. The user then adjusts the first and second wheel adjustment means, 40 and 42, to place the scraping surface 18 in operative contact with the bulk material to be plowed. The user accomplishes the adjustment by removing the removable locking pin 62, adjusting the sliding member to place the wheels in the desired position, then re-inserting the removable locking pin 62 into the appropriate adjusting hole 64. A user then adjusts the adjustable chain loop 50 to give the desired length of chain 46. The adjustable chain loop 50 is then placed on the second connection point 72 on the vehicle's bumper. Placing the adjustable chain loop 50 over the second connection point fixes the angle of the blade 12 with respect to the vehicle's bumper. This effect can be seen by referring to FIG. 7. If a user desired to move the second end 22 closer to the vehicle's bumper, he would simply increase the adjustable loop's diameter 50, decreasing the length of the chain 46, and moving the second end 22 closer to the vehicle's bumper. The procedure regarding the chain 46 is the same regardless of whether the first embodiment or the second embodiment of the invention is used.
In the second embodiment of the invention, a user will rotate the blade 12 so that the scraping surface 18 is in contact with the material to be plowed. This may be accomplished by several means. For example, a user can grasp the hitch plate lifting it upwardly and tilting the blade onto its back surface 16. Upon continuing to push on the hitch plate and/or the first and/or second hitch bars, 24 and 26, the plow 10 will rotate onto the scraping surface. The reverse process may be employed to rotate the plow 10 onto the fixed wheels. The releasable hitch 36 is then attached to the appropriate ball, either the upper ball 76 for plowing, or the lower ball 78 for towing the fixed wheels in contact with the roadway.
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An adjustable grading device attaching to a vehicle rear towing hitch having a grading blade for grading or snow removal and integrated wheels for transport.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to medical treatments. More specifically, the present invention relates to pressure sensing devices for medical fluids.
[0002] Due to disease, insult or injury, a person may require the infusion of a medical fluid. It is known to infuse blood, medicaments, nutrients, replacement solutions, dialysis fluids and other liquids into a patient. It is also known to remove fluid from a patient, for example, during dialysis. Dialysis is used to treat renal system failure, including kidney failure and reduced kidney function.
[0003] Renal failure causes several physiological effects. The balance of water, minerals and the excretion of daily metabolic load is no longer possible in renal failure. During renal failure, toxic end products of nitrogen metabolism (urea, creatinine, uric acid, and others) can accumulate in blood and tissues. Dialysis removes waste, toxins and excess water from the body that would otherwise have been removed by normal functioning kidneys.
[0004] Hemodialysis and peritoneal dialysis are two types of dialysis therapies commonly used to treat loss of kidney function. Hemodialysis (“HD”) treatment utilizes the patient's blood to remove waste, toxins and excess water from the patient. The patient is connected to an HD machine and the patient's blood is pumped through the machine. Catheters are inserted into the patient's veins and arteries to connect the blood flow to and from the HD machine. As blood passes through a dialyzer in the HD machine, the dialyzer removes the waste, toxins and excess water from the patient's blood and returns the blood to infuse back into the patient.
[0005] Peritoneal dialysis (“PD”) utilizes a dialysis solution or “dialysate”, which is infused into a patient's peritoneal cavity. The dialysate contacts the patient's peritoneal membrane in the peritoneal cavity. Waste, toxins and excess water pass from the patient's bloodstream through the peritoneal membrane and into the dialysate. The transfer of waste, toxins, and water from the bloodstream into the dialysate occurs due to diffusion and osmosis, i.e., an osmotic gradient occurs across the membrane. The spent dialysate drains from the patient's peritoneal cavity and removes the waste, toxins and excess water from the patient. This cycle is repeated on a semi-continuous or continuous basis. There are manual PD techniques, known as Continuous Ambulatory Peritoneal Dialysis (“CAPD”). There are also Automated Peritoneal Dialysis techniques (“APD”).
[0006] In each type of dialysis treatment, it is critical to know the pressure of the fluid that is being transported to or from the patient. Moreover, in any type of blood transfusion, saline transfusion, or any other type of fluid infusion or flow to or from a patient's body, it is important to know and control the pressure of fluid entering and leaving a patient's body.
[0007] Fluid pressure, generally, is sensed using a transducer or strain gauge. Medical fluid transducers have included strain gauges made from a silicon chip. Some medical fluid pressure transducers employ a mechanical linkage to transmit pressure from the fluid to the strain gauge. Many medical transducers, however, have abandoned the mechanical linkage in favor of a hydraulic pressure coupling medium comprised of a silicone elastomer, or “silicone gels”. In use, the gel is positioned between the medical fluid (that is sensed for pressure) and the transducer chip, wherein the gel conveys a hydraulic pressure signal to the integral sensing diaphragm of the transducer chip. At the same time, the gel isolates the chip electrically from the medical fluid.
[0008] In one type of medical transducer, the entire transducer assembly, including the chip, is discarded after a single use, since the internal components cannot be adequately cleaned for resterilization or reuse. Disposable transducer designs employing semiconductor strain gauge sensors and gel coupling media are desirable because they are rugged and accurate. Further, the disposable transducers do not require attachment of a separate disposable dome as do reusable types of medical pressure transducers.
[0009] Regardless of the advantages of the completely disposable medical pressure transducers, manufacturing costs for the pre-calibrated semiconductor chip and associated wiring of these types of transducers remain high. Moreover, the electronics, which could otherwise be reused, are thrown away with the rest of the unit. This is wasteful and costly. Indeed, because the waste contains electronics, it is more costly to dispose.
[0010] Accordingly, a pressure sensor that enables the valuable electronics of the transducer to be reused and allows the inexpensive sterile portion for the transfer of the medical fluid to be discarded is desirable. Such pressure sensors exist and typically have a dome portion, which defines a fluid lumen for the medical fluid, and a transducer portion, housing the electronics. The hurdle presented by these types of sensors is in trying to accurately transfer pressure fluctuations in the dome to like fluctuations in the transducer.
[0011] In many systems, the medical fluid carrying dome employs a first membrane and the transducer employs a second membrane. The two membranes abut one another and attempt to transmit medical fluid pressure fluctuations through to the strain gauge. One problem with these sensors that employ a membrane to membrane seal is in attempting to maintain the seal along the length of the membranes. A slight amount of air entering even a small part of the interface between the two membranes can falsify readings.
[0012] A similar problem exists with materials that have been used for the membranes. In particular, dome membranes can be susceptible to gas diffusion. Certain materials, such as ethylene propylene diene methylene (“EPDM”), have relatively high vapor transmission properties, enabling gas to diffuse from the dome, through the dome membrane, and into the interface between the membranes.
[0013] A need therefore exists for a medical fluid pressure sensor having a reusable transducer, a disposable medical fluid dome and an improved and repeatable seal between abutting membranes.
SUMMARY OF THE INVENTION
[0014] The present invention relates to medical fluid pressure sensors. More specifically, the present invention provides an apparatus that reduces the amount of air that enters between mating membranes of a pressure sensor. The pressure sensor of the present invention includes a transducer portion and separate patient or medical fluid transfer portion (referred to herein as a “dome” or a “body”). The transducer portion is reusable and the dome is disposable. The dome defines a fluid flow chamber that is bounded on one side by a dome membrane. Likewise, the transducer is mounted inside a housing, wherein the housing defines a surface that holds a transducer membrane.
[0015] The transducer can be any type of strain gauge known to those of skill in the art. In an embodiment, the sensor includes a silicone force sensing chip. The transducer membrane in an embodiment is silicone. The dome can hold and allow the transportation of many types of medical fluids such as blood, saline, dialysate (spent or clean), infiltrate, etc. The pressure sensor can likewise be used with many medical treatments, including but not limited to HD, PD, hemofiltration, and any other type of blood transfusion, intravenous transfusion, etc. Accordingly, the pressure sensor can be used with many types of medical devices including dialysis devices. In an embodiment, the reusable transducer housing mounts to the medical or dialysis device, wherein the dome or body removably couples to the housing.
[0016] The two membranes mate when the dome is fitted onto the transducer housing. The dome body and transducer housing include mating devices that enable the dome to removably couple to the housing. The pressure sensor enhances the seal between the mated membranes by creating higher localized contact forces or stresses. The pressure sensor also reduces the amount of gas that permeates from the fluid chamber across the dome membrane by making the dome membrane from a material having a low vapor transmission property.
[0017] In an embodiment the increased contact forces or stresses are provided by a sealing member or O-ring integral to the dome membrane. The integral sealing member or O-ring of the dome membrane compresses to help prevent air from leaking between the dome and transducer membranes, which mate when the housing and dome are mated. The integral O-ring can have various cross-sectional shapes and in an embodiment is at least partly circular in cross-section. The dome membrane in an embodiment also includes an integral mounting ring that pressure fits into the dome.
[0018] In another embodiment, the increased contact forces or stresses are provided by a sealing member or O-ring integral to the dome membrane in combination with a groove defined by the surface of the transducer housing. The surface of the transducer housing surrounds the transducer membrane. In an embodiment, this surface is metal, for example, stainless steel. The integral O-ring of the dome membrane compresses into the groove of the transducer housing when the housing and dome are mated. At the same time, the dome and transducer membranes are mated.
[0019] In a further embodiment, the increased contact forces or stresses are provided by a separate O-ring. Here, the O-ring compresses between the dome membrane and the surface of the transducer housing. Like the above embodiment, the surface of the transducer housing surrounds the transducer membrane and defines a groove into which the separate O-ring seats. The separate O-ring compresses into the groove of the transducer housing when the housing and dome are mated. At the same time, the dome and transducer membranes become mated.
[0020] In another embodiment, the O-ring compresses between the surface of the transducer housing and a surface of the dome. Here, either one of the surfaces of the transducer housing or the dome defines a groove into which the separate O-ring seats. The separate O-ring compresses into the groove of the transducer or dome surfaces when the housing and dome are mated. At the same time, the dome and transducer membranes become mated.
[0021] In yet another embodiment, the increased contact forces or stresses are provided by a raised portion of the surface of the transducer housing, which surrounds the transducer membrane. In an embodiment, this raised portion is metal, for example, stainless steel. The raised portion of the transducer housing compresses into the dome membrane when the housing and dome are mated. At the same time, the dome and transducer membranes become mated.
[0022] In any of the above-described embodiments for the increased contact forces, the dome membrane, in one preferred embodiment, is made of a material having a low gas permeability. That is, the dome membrane material has low vapor transmission properties. In an embodiment, the dome membrane includes butyl rubber, which is generally understood to have one of the lowest gas (especially air) permeabilities of all similar materials and is consequently one of the best rubber sealants. In another embodiment, the dome membrane includes a plurality of members or layers. One of the layers is of a material having a low gas permeability, such as a metal foil, a sputter coating of metal or a layer of saran or mylar. The other layer or layers include a flexible and expandable material, such as EPDM, silicone, polyurethane and any combination thereof.
[0023] It is therefore an advantage of the present invention to provide a pressure sensor having a reusable transducer.
[0024] Another advantage of the present invention is to provide a pressure sensor having a disposable medical or patient fluid transfer portion.
[0025] Moreover, an advantage of the present invention is to provide an accurate pressure sensor.
[0026] Still another advantage of the present invention is to provide a low cost pressure sensor.
[0027] A further advantage of the present invention is to provide a pressure sensor having a relatively gas impermeable membrane.
[0028] Yet another advantage of the present invention is to provide a pressure sensor having an additional relatively gas impermeable membrane layer.
[0029] Yet a further advantage of the present invention is to provide a pressure sensor having a localized area of high contact force.
[0030] Still further, an advantage of the present invention is to provide a pressure sensor having an integral O-ring.
[0031] Additionally, it is an advantage of the present invention to provide a pressure sensor having a separate O-ring.
[0032] Further still, it is an advantage of the present invention to provide an improved medical infusion device that employs the pressure sensor of the present invention.
[0033] Still another advantage of the present invention is to provide an improved dialysis device that employs the pressure sensor of the present invention.
[0034] Yet another advantage of the present invention is to provide an improved method of sealing membranes in a medical fluid infusion device.
[0035] Additional features and advantages of the present invention are described in, and will be apparent from, the following Detailed Description of the Invention and the Figures.
BRIEF DESCRIPTION OF THE FIGURES
[0036] [0036]FIG. 1A is a sectioned elevation view of one embodiment of the pressure sensor of the present invention having an integral O-ring that is just about to be compressed.
[0037] [0037]FIG. 1B is the sectioned elevation view of FIG. 1A, wherein the O-ring has been compressed and the pressure sensor is fully sealed.
[0038] [0038]FIG. 2 is a sectioned elevation view of one embodiment of a dome membrane of the present invention having an additional low gas permeability layer.
[0039] [0039]FIG. 3 is a sectioned elevation view of another embodiment of the pressure sensor of the present invention having an integral O-ring and a mating groove.
[0040] [0040]FIG. 4 is a sectioned elevation view of another embodiment of the pressure sensor of the present invention having a separate O-ring and a mating groove.
[0041] [0041]FIG. 5 is a sectioned elevation view of a further embodiment of the pressure sensor of the present invention having a separate O-ring and a mating groove.
[0042] [0042]FIG. 6 is a sectioned elevation view of yet another embodiment of the pressure sensor of the present invention having a raised contact force increasing portion.
[0043] [0043]FIG. 7 is a sectioned view of still another embodiment of the pressure sensor of the present invention, wherein the dome body includes a localized contact extension.
[0044] [0044]FIG. 8 illustrates various different cross-sectional shapes that the sealing member of the present invention can assume.
DETAILED DESCRIPTION OF THE INVENTION
[0045] The present invention provides a pressure sensor and a membrane therefore that helps to prevent air from entering between the membrane and a second membrane when the two membranes are mated. The membranes each belong to a separate component of the pressure sensor, namely, a fluid transfer portion (referred to herein as a “dome” or “body”) and a pressure sensing portion (referred to herein as the “transducer housing”). The pressure sensor of the present invention can be used with a variety of fluid transfusion treatments. The pressure sensor is adaptable for use with patient fluids, such as blood, urine, etc. The pressure sensor is adaptable for use with medical fluids, such as saline, dialysate (spent or clean), infiltrate, etc. The pressure sensor can likewise be used with many medical treatments, including but not limited to HD, PD (including CAPD and APD), hemofiltration, and any other type of blood transfusion, intravenous transfusion, etc.
[0046] Referring now to the figures, and in particular to FIG. 1A, one embodiment of a pressure sensor 10 is illustrated. Pressure sensor 10 includes a reusable portion or housing 12 . The housing 12 can be a separate housing that mounts to a panel or enclosure of a medical device, for example, a dialysis device or machine. The housing 12 is alternatively integral to the housing or enclosure of the medical device or dialysis machine.
[0047] The housing 12 holds or supports a transducer 14 . In the illustrated embodiment, the transducer 14 threads to the housing 12 . The transducer 14 alternatively removably mounts to the housing via fasteners, etc., or permanently mounts to the housing, for example, via a weld.
[0048] The transducer 14 includes a number of electrical conductors 16 , for example two, three or four conductors, which convey electrical signals to and from a transducer chip 18 . The electrical conductors 16 are insulated so that the electrical signals can convey away from the transducer housing 14 to a pressure monitor (elsewhere on the medical or dialysis machine or to a remote device) without risk of shocks, shorts or signal distortion. The chip 18 in an embodiment is a silicone force sensing chip. The housing 12 , into which the transducer 14 and chip 18 mount is, in an embodiment, stainless steel.
[0049] The transducer housing 12 defines a chamber 20 , which in an embodiment holds a pressure transmitting and an electrically and biologically isolating gel, hydraulic fluid or other type of pressure transmission material 22 . In an embodiment the pressure transmission material 22 includes silicone. Regardless of the type of pressure transmission material 22 used, the material 22 is responsive to negative or positive pressure signals from the medical fluid flowing through the dome or body. The material 22 transmits the positive or negative pressure signals to the transducer chip 18 . In an embodiment, the transducer chip 18 includes a pressure sensing surface, which is exposed to the pressure transmission material 22 . Also, in an embodiment, the chip 18 includes on-chip circuitry for predetermined gain and temperature compensation.
[0050] A disposable body or dome 30 removably mounts to the transducer housing 12 . The disposable body or dome 30 is detached from the reusable transducer housing 12 usually after a single use. The dome 30 defines an inlet fluid port 32 , an outlet fluid port 34 and a fluid chamber 36 . The illustrated embodiment defines a generally “T” shaped inlet/outlet, wherein the chamber 36 forms the leg of the “T”. The dome 30 or body can otherwise define angled or “V” shaped inlets and outlets and/or a contoured chamber. One such dome is disclosed in published PCT application WO 99/37983, entitled, “Connecting Element for Connecting a Transducer With a Sealed Fluid System”, the teachings of which are incorporated herein by reference. PCT application WO 99/37983 discloses a dome ceiling, similar to the ceiling 38 of the present invention, which is curved and has a central portion that slopes downward towards the chamber 36 and the membranes.
[0051] The body 30 can be constructed from any inert, biologically safe material, such as an inert plastic, for example, a polycarbonate. In an embodiment, the body 30 is clear or transparent. The inlet port 32 and outlet port 34 can include any suitable medical industry interface for connecting to a tube connector or directly to medical fluid tubes. The ports can individually or collectively include a conical packing seat.
[0052] The dome or body 30 releasably engages the transducer housing 12 . In an embodiment, the body 30 includes a series of tabs 40 that frictionally engage a mating ring 42 defined by the housing 12 . When a user presses the body 30 onto the housing 12 , the tabs 40 bend slightly outward so that tips 44 of the tabs 40 slide over a rib 46 partially defining the ring 42 . Eventually the tips 44 extend far enough over the housing 12 , wherein the tips 44 snap into the ring 42 . Each of FIGS. 1 and 3 to 6 show the body 30 as it is just about to fully engage the housing 12 (with the tops 44 shown figuratively overlapping the rib 46 ). The body 30 disengages from the housing 12 in the opposite manner, wherein the tabs 40 again bend outwardly, so that the tips 44 slide back over the rib 46 and away from the ring 42 .
[0053] Both the housing 12 and the body 30 of the pressure sensor 10 include a flexible membrane. The housing 12 includes a membrane 50 disposed over and defining a bounding surface of the chamber 20 . The membrane 50 is positioned substantially flush along the top surface (e.g., stainless steel surface) 52 of the housing 12 . The transducer membrane 50 is, in an embodiment, silicone of approximately 0.1 to 0.5 mm thickness. Other materials and thicknesses may be used for the transducer membrane 50 .
[0054] The transducer membrane 50 contacts the dome membrane 60 when the dome 30 and the housing 12 have been mated together. The contacting membranes 50 and 60 enable positive and negative pressure fluctuations of medical or patient fluid in the chamber 36 of the body 30 to be transmitted to the transmission material 22 and to the chip 18 . In past pressure sensors, the interface between the contacting membranes 50 and 60 has become corrupted with gas leaking into the interface through the sides of the membranes 50 and 60 and from the medical or patient fluid though a relatively gas permeable dome membrane. The present invention seeks to address both these problems.
[0055] First, the dome membrane 60 is made from a substantially gas impermeable material. In a preferred embodiment, the dome membrane 60 is made from butyl rubber or from a blended rubber using butyl, such as halobutyl rubber. Butyl is generally known to have very good sealing properties and have a very low gas permeability rate. Butyl also has relatively good tear strength, chemical resistance, environmental resistance (including resistance to ozone attack) and is relatively easy to manufacture. The membrane 60 material can be made using a high state of cure (i.e., crosslink density), wherein the crosslinking reduces the rate of permeation.
[0056] Butyl rubber, with respect to air at standard temperature and pressure, is approximately thirty-five times less permeable than ethylene propylene diene methylene (“EPDM”), a known membrane material. Butyl rubber is approximately eighteen times less permeable than natural rubber. Other materials, besides butyl, which have low vapor permeability or transmission rates, and which alone or in combination with butyl rubber or with each other, can be used in the present invention, include neoprene (about 7.5 times less permeable than EPDM), polyurethane (about 6.7 times less permeable than EPDM), Buna-N (Nitrile) (about 7.5 times less permeable than EPDM), Alcryn® (about 25 times less permeable than EPDM), Hypalon® (about 13.5 times less permeable than EPDM), Vamac® (about 19 times less permeable than EPDM), and Viton® (about 19 times less permeable than EPDM).
[0057] The membrane 60 also defines a sealing rib 62 that press fits inside of an annular ring 64 defined by the body 30 . In an embodiment, sealing rib 62 has an inner radius slightly less than the inner radius of the annular ring 64 , so that the membrane 60 has to stretch to fit the rib 62 inside of the ring 64 . The sealing rib 62 and the thin portion of the membrane (that engages at least a portion of the membrane 50 ) are made of the same material in an embodiment, but may be of different materials in other embodiments. The thin, sealing portion of the membrane 60 is, in an embodiment, approximately 0.4 mm thick.
[0058] [0058]FIG. 1B illustrates the pressure sensor 10 of FIG. 1A, which is now fully sealed. The dome or body 30 is now ready to receive a medical fluid. The dome membrane 60 is flush against the transducer membrane 50 . That is, the dome membrane 60 sealingly engages the transducer membrane 50 . When the dome membrane 60 moves due to either a positive or negative pressure fluctuation of medical fluid in chamber 36 , the transducer membrane 50 follows or moves along with the dome membrane 60 . The transducer membrane 50 in turn imparts a positive or negative force on the transmission material 22 , which activates the chip 18 of the transducer 14 .
[0059] Referring now to FIG. 2, another embodiment for making a low vapor permeable dome membrane 70 is illustrated. The dome membrane 70 includes the sealing rib 62 described above. The dome membrane 70 also includes a low vapor transmission layer 72 . The low vapor transmission layer 72 can be a layer of metal foil, a sputter coating of metal, saran, mylar and any combination thereof. In another embodiment, the low vapor transmission layer 72 includes butyl rubber, one of the other low vapor transmission materials described above or a film such as SiO2 glass film and EvOH barrier film. In a further embodiment, a low vapor transmission filler is used, such as a reinforcing or lamellar type, which has a plate-like structure that lengthens the diffusion pathway and reduces the rate of permeation.
[0060] The low vapor transmission layer 72 in an embodiment is co-extruded with the rest of the membrane 70 , so that the layer 72 resides within outer layers 74 of a flexible material, which may also have a low or high vapor transmission rate. The outer layers 74 can include any type of flexible material, for example, EPDM, silicone, polyurethane or any combination of these. In another embodiment, the low permeability layer 72 is bonded to the flexible layer 74 via a suitable adhesive or heat sealing technique.
[0061] The low permeability membranes 60 and 70 tend to prevent gas entrained in the medical or patient fluid in the chamber 36 of the dome 30 , or present when no medical/patient fluid resides in the chamber 36 , from permeating across the dome membrane 60 or 70 . Either of the dome membranes 60 and 70 can be used in the embodiments for creating local areas of high contact force, which are about to be presented in FIGS. 1 and 3 to 6 . The increased contact forces act to keep gas from entering between the sides of the dome membrane 60 or 70 and the transducer membrane 50 .
[0062] [0062]FIGS. 1A and 1B illustrate one embodiment, wherein the increased contact forces or stresses are provided by an O-ring or sealing member 80 , which is formed integrally to the dome membrane 60 or 70 . The integral O-ring 80 of the dome membrane 60 or 70 compresses to the top surface (e.g., stainless steel surface) 52 of the housing 12 to help prevent air from leaking between the sides of the dome membrane 60 or 70 and the transducer membrane 50 . The integral O-ring 80 compresses enough so that the dome membrane 60 or 70 contacts and seals to the transducer membrane 50 . The integral O-ring 80 is co-extruded or co-molded with the remainder of the dome membrane 60 and with at least part of the dome membrane 70 .
[0063] Referring now to FIG. 3, in another embodiment, the increased contact forces or stresses are provided by the integral O-ring 80 in combination with a groove 82 defined by the surface 52 of the transducer housing 12 . The groove 82 is formed to fit the cross-sectional shape of the O-ring 80 . The surface 52 of the transducer housing 12 surrounds the transducer membrane 50 and is metal, for example, stainless steel. The integral O-ring 80 of the dome membrane compresses into the groove 82 of the transducer housing 12 when the housing and dome are mated, so as to allow the dome membrane 60 or 70 and transducer membrane 50 to contact and seal to each other.
[0064] Referring now to FIG. 4, in a further embodiment, the increased contact forces or stresses are provided by a separate O-ring or sealing member 90 . In an embodiment, the O-ring 90 compresses between the dome membrane 60 or 70 and the surface 52 of the transducer housing 12 . Here, like the above embodiment, the surface 52 of the transducer housing 12 surrounds the transducer membrane 50 and defines a groove 92 into which the separate O-ring 90 seats. The separate O-ring 90 compresses into the groove 92 of the transducer housing 12 when the housing and dome are mated, so as to allow the dome membrane 60 or 70 and transducer membrane 50 to contact and seal to each other. The separate O-ring 90 can have any of the cross-sectional shapes described below, wherein the groove 92 has a similar shape. The groove 92 in an embodiment also serves to provide a storage place for the separate O-ring 90 , during packaging, shipping and set-up. The O-ring 90 therefore slightly pressure fits into the groove 92 .
[0065] Referring now to FIG. 5, in another embodiment, the O-ring or sealing member 90 compresses between the surface 52 of the transducer housing 12 and a surface 94 of the body 30 . Here, either one of the surfaces 52 or 94 of the transducer housing 12 or the dome 30 , respectively, defines a groove 92 (in surface 52 shown previously in FIG. 4) or 96 (in surface 94 ) into which the separate O-ring 90 seats and is stored during packaging, shipping and set-up. The separate O-ring 90 compresses into the groove 92 or 96 of the transducer or dome surfaces 52 or 94 , respectively when the housing and dome are mated, so as to allow the dome membrane 60 or 70 and transducer membrane 50 to contact and seal to each other. The separate O-ring 90 can have any of the cross-sectional shapes described below, wherein the groove 92 or 96 has a similar shape.
[0066] Referring now to FIG. 6, in yet another embodiment, the increased contact forces or stresses are provided by a raised portion 98 of the surface 52 of the transducer housing 52 , which surrounds the transducer membrane 50 . In an embodiment, the raised portion 98 is metal, for example, stainless steel. The raised portion 98 of the transducer housing 12 compresses into the dome membrane 60 or 70 at a point where the membrane 60 or 70 is backed up by the sealing rib 62 , i.e., where the membrane 60 or 70 has enough material to accept the raised portion 98 . The raised portion 98 , like the O-rings, can have a variety of cross-sectional shapes, such as rectangular, trapezoidal, circular, etc. The raised portion 98 compresses into the dome membrane 60 or 70 when the housing 12 and dome 30 are mated, so as to allow the dome membrane 60 or 70 and transducer membrane 50 to contact and seal to each other.
[0067] Referring now to FIG. 7, yet another embodiment places a raised portion on the dome or body 30 rather than the transducer housing 12 as in FIG. 6. Here, the increased contact forces or stresses are provided by an extension 99 of the surface 101 of the dome 30 , which surrounds the transducer membrane 50 . In an embodiment, the extension 99 is made of the same material as the dome 30 , for example, plastic. The extension 99 of the transducer housing 12 compresses into the dome membrane 60 or 70 at a point where the membrane 60 or 70 is backed up by the sealing rib 62 , i.e., where the membrane 60 or 70 has enough material to accept the extension 99 .
[0068] The extension 99 , like the O-rings, can have a variety of cross-sectional shapes, such as rectangular, trapezoidal, circular, etc. As illustrated, the extension 99 compresses into the dome membrane 60 or 70 when the housing 12 and dome 30 are mated, so as to allow the dome membrane 60 or 70 and transducer membrane 50 to contact and seal to each other. Further, the annular ring 64 presses on the sealing rib 62 so that the membrane 60 or 70 also seals generally to the surface 52 of the transducer housing 12 .
[0069] Referring now to FIG. 8, any of the sealing members disclosed herein, such as the integral O-ring 80 or the separate O-ring 90 , can have at least a partially circular cross-sectional shape as illustrated in FIGS. 1 and 3 to 6 . Alternatively, the sealing members can have various partial or full cross-sectional shapes, such as those shapes commonly associated with a delta-ring 102 , D-ring 104 , T-ring 106 , square-ring 108 , lobed-ring 110 , cored-ring 112 , hollow-ring 114 and K-ring 116 .
[0070] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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The present invention lessens the amount of air entering between mating membranes of a pressure sensor. The pressure sensor of the present invention includes a transducer portion and separate patient or medical fluid transfer portion or dome. The transducer portion is reusable and the dome is disposable. The dome defines a fluid flow chamber that is bounded on one side by a dome membrane. Likewise, the transducer is mounted inside a housing, wherein the housing defines a surface that holds a transducer membrane. The two membranes mate when the dome is fitted onto the transducer housing. The pressure sensor enhances the seal between the mated membranes by creating higher localized contact stresses. The pressure sensor also reduces the amount of gas that permeates from the fluid chamber across the dome membrane and between the interface by making the dome membrane from a material having a low vapor transmission.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a nebulizer for spraying a liquid with high efficiency, and particularly to a nebulizer suitable for use in an inductively coupled plasma/mass spectrometry system (ICP-MS), an inductively coupled plasma (ICP) atomic emission spectrometry system and an atomic absorption spectrometry system used for inorganic substance analysis.
2. Description of the Related Art
In analytical apparatuses for inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES), etc., aerosol is produced from a solution sample by a nebulizer and introduced into a plasma. Here, substances to be analyzed are brought into atomization, excitation and ionization. Owing to a mass analysis for the resultant ions or a spectrometric analysis for light emitted from excited atoms or ions, the identification and determination of each substance to be analyzed present in the liquid sample are realized. A concentric glass nebulizer is often used as the nebulizer. A description related to ICP-AES is disclosed in, for example, Analytical Chemistry, 54(1982), p.533-p.537. At an end of each spray tube, atmospheric pressure becomes less than or equal to 1 atom. by a spray gas. A difference in pressure between the two ends of the tubes is used so that the liquid sample is sucked into the nebulizer from a container. The flow rate of the gas is 1.0 L/min. and the flow rate of the liquid is about 1.0 mL/min.
A micro concentric nebulizer (MCN) related to ICP-MS has been described in Journal of Analytical Atomic Spectrometry, 11(1996), p.713-p.720. A liquid sample is delivered to a single capillary and sprayed around its end by gas which passes therethrough. The flow rate of the gas is about 1.0 L/min. Since the velocity of the gas is faster than that for the concentric glass nebulizer, the efficiency of its spraying is relatively high. However, the introduced flow rate of a sample solution for realizing high-efficiency spraying is limited. The efficiency of the spraying is reduced when the flow rate thereof is 50 μL/min or more.
There is need to prevent deposition of a metal due to heat generated upon cutting work, polishing, etc. Thus, a description related to a spray-like body supply device intended for cooling has been disclosed in Japanese Patent Application Laid-Open No. Hei 8-99051. If a liquid is produced or formed in spray form, then cooling can be carried out more effectively. The device has capillaries through which the liquid flows, and an injection hole (nozzle) from which a spray gas (air) is discharged. The cooling liquid is divided into a plurality of the capillaries, and the ends of the plurality of capillaries are packed into a bundle. The liquid is sprayed at the ends thereof by an air flow discharged through one injection hole. The nozzle is shaped in tapered form.
Japanese Patent Application Laid-Open No. Hei 7-306193 describes a sonic spray ionization technology. A quartz capillary (whose inner and outer diameters are 0.1 mm and 0.2 mm respectively) in which a liquid is introduced, has an end inserted into an orifice (whose inner diameter is 0.4 mm). A high-pressure nitrogen gas introduced inside an ion source is discharged into the air through the orifice, and the liquid is sprayed by a sonic gas flow formed at this time. Gaseous ions are produced in aerosol produced by the spraying. In the present ionizing method, the production of fine droplets by the sonic gas flow essentially plays an important role. The liquid in the sonic gas flow is torn off by a gas flow fast in velocity to thereby produce droplets. The non-uniformity of the concentrations of positive and negative ions in droplets firstly produced by spraying becomes pronounced as the size of each droplet becomes fine. Further, some of the liquid are separated from the surface of the droplet by a gas flow, whereby charged fine droplets are produced. Such fine droplets are evaporated in a short time so that gaseous ions are produced. While the size of each produced droplet decreases with an increase in the velocity of flow of gas, the droplet size increases as the velocity of flow of gas enters a supersonic region. This is because a shock wave is produced in the case of the supersonic flow, and the production of fine droplets is depressed. Therefore, according to the sonic spray ionizing method, when the gas flow is sonic, the finest droplets are produced and the produced amount of ions reaches the maximum. The present method discloses that when the flow rate of the spray gas is 3 L/min., a sonic gas flow is formed.
A sonic spray nebulizer has been described in Analytical Chemistry, 71(1999), p.427-p.432. The nebulizer is similar in structure to the ion source for sonic spray ionization. The inner diameter of a resin orifice is 0.25 mm and a quartz capillary (whose inner and outer diameters are 0.05 mm and 0.15 mm respectively) is used. Since a sonic gas flow is used in a spray gas, the present nebulizer is capable of producing extremely fine droplets. As a result, the spray efficiency of a liquid is greatly improved as compared with the conventional glass nebulizer. In the sonic spray nebulizer, the flow rate of the gas is fixed to the condition for the generation of the sonic gas flow, and the flow rate of a liquid sample is controlled by a pump. The flow rate of the gas ranges from 1.0 L/min. to 1.4 L/min., and the flow rate of the liquid ranges from 1 μL/min. to 90 μL/min.
On the other hand, a nebulizer using a supersonic gas flow has been described in Japanese Patent Application Laid-Open No. Hei 6-238211 and U.S. Pat. No. 5,513,798. The present nebulizer is characterized in that a supersonic gas flow is helically produced in the neighborhood of a liquid outlet at an end of a capillary by a helical gas path. Further, a cylindrical path is placed on the downstream side from an orifice unit and a shock wave of a supersonic gas flow is repeatedly reflected by the inner surface of the path. Since the shock wave collides with a liquid flow many times in an in-path central portion, droplets are efficiently produced from the liquid cut to pieces. The length (corresponding to the distance between the end of the capillary and the surface of the cylindrical path, which is brought into contact with the air) is as about twice as the diameter of the cylindrical path. The flow rate of gas ranges from 50 L/min. to 60 L/min., and the flow rate of the liquid ranges from 91 mL/min. to 100 mL/min. Since the spray gas helically circles round, the formation of a gas flow concentrically with the capillary as described in the prior art is not carried out. The velocity of flow of the spray gas is divided or resolved into a horizontal direction and a vertical direction with respect to the axis of the capillary. While the velocity of flow of the gas is supersonic, a flow velocity component horizontal to the capillary axis is considered to be less than or equal to the speed of sound. In a droplet producing process, the application of the shock wave to the liquid is important and no emphasis is placed on the tearing off of the liquid by a high-speed gas flow.
Upon vaporization of the liquid, the flow rate of fully-vaporizable water per gas flow rate 1 L/min. is about 20 μL/min. at most if calculated from saturated vapor pressure at 20° C. Therefore, if sample solution given at a flow rate of 20 μL/min. or more is introduced into an ideal nebulizer when the flow rate of the gas is about 1 L/min., then the efficiency of its spraying should have been reduced in the ideal nebulizer. However, an actual nebulizer shows a tendency to improve analytical sensitivity even if the sample flow rate is 20 μL/min. or more. This is because the spray efficiency of the liquid is considered not to have reached an ideal level.
In the concentric glass nebulizer, the flow rate of the liquid is about 500 μL/min. when the liquid is automatically sucked. Therefore, the full vaporization of liquid cannot be carried out when the flow rate is a gas flow of about 1 L/min. Since a gas flow path is narrow and long structurally, the gas introduced into the nebulizer suffers a pronounced pressure loss in the neighborhood of a jet or injection port or outlet. As a result, the flow velocity of the spray gas is much slower than the speed of sound and the size of each produced droplet is about 10 μm. Most of droplets produced by spraying are coagulated or condensed, whereby they are released from aerosol so as to return to the liquid. Therefore, the spray efficiency of the liquid become extremely low and reaches 1% to 3%. Further, the nebulizer is capable of suitably setting the flow rate of a sample solution through the use of a pump. However, a problem arises in that when the flow rate of the sample solution to be introduced is 300 μL/min. or less, the spraying becomes unstable and hence the nebulizer cannot be used. Therefore, the nebulizer cannot be coupled or linked to a semi-micro liquid chromatographor (liquid flow rate of about 200 μL/min.). (An elementary analytical apparatus might be used to perform a chemical speciation analysis as well as an elementary analysis. In this case, a sample liquid is separated according to the semi-micro liquid chromatography and the separated liquid is introduced into the nebulizer). Even if the flow rate of the liquid sample is increased in a range from 400 μL/min. to 1000 μL/min., the sensitivity of the analytical apparatus little increases. This shows that the substantial amount of the sample introduced into a plasma does not increase.
The micro concentric nebulizer is different from the concentric glass nebulizer, and reduces the flow rate of the liquid sample and improves the efficiency of its spraying. This is because the flow velocity of the gas is considered to be high as compared with the concentric glass nebulizer. Therefore, the micro concentric nebulizer is characterized in that a liquid sample available by a small quantity can be analyzed. However, the flow rate of a liquid sample, which allows the maintenance of high spray efficiency, is less than or equal to 50 μL/min. When the flow rate thereof is greater than that, the sensitivity of the analytical apparatus little increases. As a result, the micro concentric nebulizer is accompanied by a problem in that when liquid samples identical in concentration are analyzed, the sensitivity of the analytical apparatus is low as compared with the use of the concentric glass nebulizer. A problem arises in that particularly when a chemical speciation analysis which uses a semi-micro liquid chromatograph jointly, is performed, the flow rate of a liquid reaches about 200 μL/min. and the sensitivity of the analytical apparatus is insufficient.
The sonic spray nebulizer has a problem similar to the micro concentric nebulizer. While the present sonic spray nebulizer is a nebulizer capable of introducing a liquid given at a low flow rate with high efficiency, it uses a sonic gas flow for the purpose of liquid spraying. Since a wide gas flow path is provided therein, a pressure loss of gas is very low and the sonic gas flow can easily be formed. Further, since the end of a capillary in which the liquid is introduced, is placed in the center of an orifice used as a gas jet port or outlet, the efficiency of spraying is extremely high. However, the flow rate of a liquid sample, which allows the implementation of high spray efficiency, is about 60 μL/min. or less in the sonic spray nebulizer in a manner similar to the micro concentric nebulizer. When the flow rate is greater than that, the spray efficiency is reduced and the sensitivity of an analytical apparatus does not increase significantly.
As described above, the liquid is sprayed through the use of the high-speed (sonic) gas flow in the concentric glass nebulizer, the micro concentric nebulizer, and the sonic spray nebulizer. These nebulizers are respectively accompanied by a problem in that while spraying is carried out through the single jet or injection port or outlet, the spray efficiency is reduced with an increase in flow rate when the liquid flow rate is greater than or equal to about 60 μL/min. When they are installed in a plasma mass analyzer or a plasma atomic emission spectrometry system, it is necessary to properly use nebulizers such as a glass nebulizer, etc. according to the flow rate of the liquid sample, thus causing inconvenience. Particularly when the chemical speciation analysis is done which uses jointly a semi-micro liquid chromatograph in which the liquid flow rate is about 200 μL/min., a problem arises in that, for example, the spraying becomes unstable, thereby making each nebulizer incapable of use, and the spray efficiency becomes low.
As indicated by the sonic spray ionization technology, the size of each produced droplet depends on the gas flow rate. When the flow rate of the spray gas is sufficiently high, the spray efficiency reaches the maximum in the case of the sonic gas flow owing to the effects of tearing off the liquid by the sonic gas flow, and hence the spray efficiency of the liquid becomes high. Japanese Patent Application Laid-Open No. Hei 9-239298 discloses that when a gas flow rate is 3 L/min., a sonic gas flow is formed. Thus, when no limitation is imposed on the gas flow rate relative to the liquid flow rate, the size of each of droplets produced by spraying reaches the minimum upon the speed of sound, and hence droplets each having a sub-micron size of about 0.7 μm are produced in large quantities. When a gas flow slightly faster than the speed of sound is used, the size of each droplet actually tends to increase on the average, but droplets of sub-micron sizes are produced. However, a limitation is often imposed on the flow rate of a usable spray gas in an actually-used nebulizer. In the plasma atomic emission or mass spectrometry system, for example, the flow rate of the spray gas is required to set to about 1 L/min. A restriction is imposed on the gas flow rate relative to the liquid flow rate in order to increase the spray efficiency of a liquid to the maximum under the condition that the gas flow rate is kept constant. As a result, the size of each droplet reaches the minimum where a supersonic gas flow other than the sonic gas flow is formed. This is because even if a shock wave for restraining or controlling the scale-down of each droplet is formed, the production of fine droplets by a gas-flow tearing-off effect becomes effective if a gas flow faster than the speed of sound is formed. Namely, it is desirable that the velocity of flow of the gas is supersonic rather than sonic or less in order to produce droplets each having a sub-micron size in large quantities at a constant gas flow rate and increase the spray efficiency of the liquid to the maximum.
In the nebulizer described in U.S. Pat. No. 5,513,798 which aims to spray a large quantity of liquid in a large quantity of gas, a supersonic spray gas flow is used. In the present nebulizer, the gas flow is not formed concentrically with the capillary as described in the prior art, and the spray gas helically circles round. Droplets of 2 μm to 10 μm are produced by applying a shock wave to the liquid without using the effects of tearing off the liquid by a high-speed gas flow. Since each droplet is large and micron in size, it is difficult to implement an increase in the sensitivity of each system even if the present nebulizer is used as nebulizers for a spectrometry system and a measuring system. Further, since the helical gas flow is formed, the gas flow path is structurally narrow and complex, and the pressure of gas introduced into the nebulizer reaches significant high pressure. A problem arises in terms of fabrication upon applying such a nebulizer to the case where the gas flow is low. While the gas flow rate is set to 1 L/min. in the nebulizers for the ICP atomic emission spectrometry system and the ICP-MS in particular, it is extremely difficult to fabricate a nebulizer which copes with such a low gas flow rate. This is because the gas flow path needs high-accuracy micro-fabrication for the purpose of forming the helical gas flow. A problem arises in that since the high-pressure gas is used, a gas supply means as well as the nebulizer also needs to have high pressure resistance.
In the nebulizer described in Japanese Patent Application Laid-Open No. Hei 8-99051, the introduced liquid is divided into the large number of capillaries. The ends of the large number of capillaries are packed into the bundle, and the liquid is sprayed by the gas flow discharged from one jet or injection port or outlet. However, the capillaries lying in the center of the bundle are hard to contact the gas flow, and the spray efficiency becomes relatively low. The structure of the nozzle shaped in tapered form suffers a noticeable pressure loss, and a high-speed gas flow is hard to occur.
In the conventional nebulizers as described above up to now, the sufficient spray efficiency was not always obtained and a limitation was imposed on an applicable liquid flow-rate range from the viewpoint of the production of the droplets of sub-micron sizes in large quantities.
SUMMARY OF THE INVENTION
An object of the present invention is to provide nebulizer with high spray efficiency, which is capable of producing droplets of sub-micron sizes in large quantities from a wide range of liquid flow rates under a limited gas flow rate.
In order to solve the above problems, the present invention provides a nebulizer which effectively makes use of the momentum of a gas flow for purposes of liquid spraying by using a supersonic spray gas flow lying in the axial direction of a capillary (flow path). Further, the present invention provides a nebulizer provided with a plurality of spray units.
How to increase an opportunity to allow a spray gas and a liquid to collide with each other in a limited time or space is of extreme importance upon spraying the liquid using a compressed gas. Therefore, a solution and gas are uniformly distributed to each individual spray units to thereby make it possible to increase the probability of contact between the solution and the gas.
When the limited spray gas is distributed to the respective spray units, the flow rate thereof is greatly reduced. In order to improve the effects of making collision between the spray gas and the liquid, a supersonic gas flow having much momentum as compared with a sonic gas flow is used. As a result, fine droplets can be produced with satisfactory efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional illustration of the supersonic array nebulizer;
FIG. 2 is an enlarged illustration of part of the nebulizer in FIG. 1;
FIG. 3 is relationship between the flow rate of nebulizer gas and the annular area for ejection of nebulizer gas;
FIG. 4 is comparison of variation of signal intensity at different sample uptake rate for the supersonic spray array nebulizer, the sonic spray nebulizer and the conventional concentric nebulizer;
FIG. 5 is a cross-sectional illustration of the supersonic spray array nebulizer with orifices formed by using pieces of resin tube;
FIG. 6 is an enlarged illustration of part of the nebulizer in FIG. 5;
FIG. 7 is an enlarged illustration of the supersonic spray array nebulizer whose orifices are formed on pieces of ceramic material disk;
FIG. 8 is an enlarged illustration of the supersonic spray array nebulizer whose orifices are formed on a single piece of ceramic material disk;
FIG. 9 shows a sample introduction system in which the supersonic spray array nebulizer combines with a membrane separator for solvent removal;
FIG. 10 shows a sample introduction system in which the supersonic spray array nebulizer combines with a cooling device for solvent removal;
FIG. 11 is a schematic diagram of an inductively coupled plasma mass spectrometry system in which a semi-microcolumn is connected with the supersonic spray array nebulizer;
FIG. 12 is a schematic diagram of an analytical instrument system which includes several semi-microcolumns connected with the supersonic spray array nebulizer;
FIG. 13 is a schematic diagram of an inductively coupled plasma mass spectrometry system which employs the supersonic spray array nebulizer combined with a flow injection equipment;
FIG. 14 is a schematic diagram of an inductively coupled plasma mass spectrometry system which employs the supersonic spray array nebulizer combined with an electrophoresis device for chemical speciation analysis;
FIG. 15 is a schematic diagram of using the supersonic spray array nebulizer for an inductively coupled plasma atomic emission spectrometry system;
FIG. 16 shows experimental results obtained with the inductively coupled plasma atomic emission spectrometry system which employs the supersonic spray array nebulizer for sample introduction;
FIG. 17 is a schematic diagram of an atomic absorption spectrometry system which employs the supersonic spray array nebulizer for sample introduction;
FIG. 18 is a cross-sectional illustration of a supersonic spray nebulizer with a single orifice;
FIG. 19 is an enlarged illustration of part of the nebulizer described in FIG. 18;
FIG. 20 is a cross-sectional illustration of a single-orifice supersonic spray nebulizer without using a plate to fix the tube;
FIG. 21 is a cross-sectional illustration of a sonic spray nebulizer with a helical flow path for nebulizer gas;
FIG. 22 is a pictorial illustration of the supersonic spray array nebulizer with a tool; and
FIG. 23 is a pictorial illustration of part of the nebulizer for gas ejection.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will hereinafter be described in detail with reference to the accompanying drawings.
Embodiment 1
FIG. 1 is a cross-sectional view of a supersonic array nebulizer based on one embodiment of the present invention. FIG. 2 is an enlarged view of orifices shown in FIG. 1 . The present supersonic array nebulizer is characterized in that it sprays a supersonic region gas and has a plurality of spray units. Each of the spray units comprises an orifice 4 through which a spray gas or pressurized gas is discharged, and a tube (capillary) 5 through which a sample liquid is introduced. The supersonic region spray gas is injected or delivered through a clearance (jet outlet or tip) defined between the orifice 4 and the tube 5 . The liquid sample is divided into several spray units and simultaneously sprayed. Since the flow rate of the liquid sample introduced into each individual units is reduced as compared with the single spray unit, high-efficiency spraying is implemented as a whole. A liquid flow-rate range, which allows the implementation of the high-efficiency spraying, is enlarged.
The supersonic array nebulizer is formed by connecting a first member 1 to a second member 2 with a screw 3 . A terminal or end portion of each tube 5 into which the sample liquid is introduced, is inserted into each orifice 4 . The end portion of each tube 5 is placed on substantially the same surface as the outside of the orifice 4 . A gas supplied from a gas supply means is introduced through a gas inlet 6 and delivered from the orifice 4 to thereby spray the liquid. Each tube 5 is fixed by a fixing plate placed on the upstream side of an orifice member 7 . In order to introduce the spray gas into the orifice member 7 , the fixing plate 8 is provided with gas pass-through portions. Further, the tube 5 is fixed to a fixing tube 9 with an adhesive 10 to thereby prevent the leakage of the spray gas to the outside of the nebulizer and the leakage of a liquid solution through a gap or clearance defined between the tube 5 and the tube 9 . Since a gas flow path is wide inside the nebulizer using the first member 1 and the second member 2 , a loss of gas pressure is little produced between the gas supply means and the orifice 4 . When the pressure of the gas supplied from the gas supply means is 5 atmospheric pressures, the pressure inside the nebulizer becomes 4.8 atmospheric pressures. The thickness of the orifice member 7 is normally less than or equal to 1.5 mm. In the structure referred to above, a supersonic region gas flow can be formed through the orifice member 7 if the pressure of a gas source is set to about 4 to 5 atmospheric pressures. It is considered in such a nebulizer that the effect of tearing off the liquid by a high-speed gas flow acts effectively and droplets of sub-micron sizes can be produced in large quantities.
In FIG. 1, the reference numbers 11 , 12 , and 13 , respectively, show a connection fitting, a tube for sample solution delivery and a connecting tube.
The flow rate of a spray gas applied to a plasma atomic emission analytical system normally ranges from 0.5 L/min. through 1.5 L/min. and is placed under severe limitations. It is desirable that when consideration is given to the saturated vapor pressure of water, the velocity of flow of a gas falls within a supersonic region when the ratio between the flow rate of a liquid and the flow rate of the gas is greater than 5×10 −5 . A larger quantity of energy can be used for liquid spraying and hence the efficiency of spraying can be improved.
The velocity of flow of the spray gas discharged from the orifice depends on gas pressure on the upstream side of the orifice, the thickness of the orifice member, etc. When the thickness of the orifice member is negligible, the velocity of flow of the spray gas reaches substantially the velocity of sound (Mach 1) when the gas pressure on the upstream side of the orifice reaches 1.9 atmospheric pressures. When the gas pressure reaches 7.8 atmospheric pressures, a supersonic flow of Mach 2 is formed. However, when the thickness of the orifice member is greater than or equal to 2 mm, a pressure loss of the gas at the orifice member is significantly produced. Thus, no sonic gas flow is formed unless the gas pressure on the upstream side of the orifice is set to an extremely high pressure. Higher pressure is required to form the supersonic flow. A gas supply unit such as a regulator of a commonly-used gas cylinder is set to a gas pressure corresponding to about 5 atmospheric pressures at most. Therefore, the thickness of the orifice may desirably be 1.5 mm or less. On the other hand, a problem arises in that when the thickness of the orifice member is less than or equal to 0.1 mm, it breaks from the viewpoint of strength. It is therefore desirable that the thickness of the orifice member ranges from 0.1 mm to 1.5 mm. In the present embodiment, the thickness of the orifice member was set to 0.2 mm and the gas pressure at the gas supply unit was set to 5 atmospheric pressures.
The spray gas is injected through the clearance (space) between the orifice and the tube. The volume (corresponding to annular sectional area x thickness of orifice member) of a space shown in FIG. 23 is important for the purpose of forming the supersonic gas flow. It is desirable that a space volume per spray-gas flow rate equivalent to 1 L/min. is set within a range from 3.6×10 6 to 5.1×10 6 μm 3 in each spray unit. When the space volume is less than or equal to 3.6×10 6 μm 3 , the supersonic gas flow cannot be formed unless a gas pressure of 7 atmospheric pressures or higher is applied. It is therefore necessary to form devices around the nebulizer as high-pressure resistant and sturdy ones. Thus, the entire system is brought into large size and high cost. On the other hand, when the gas pressure is less than or equal to 7 atmospheric pressures, the generation of a supersonic gas flow having a flow velocity of Mach 2 or more is actually impossible in principle. Therefore, the gas pressure may desirably be used within a range from 1.9 to 7 atmospheric pressures, and the velocity of the generated gas flow falls within a range of Mach 1 to 2.
On the other hand, when the space volume is greater than or equal to 5.1×10 6 μm 3 , the flow velocity of the gas is lowered and hence no gas reaches the supersonic region. In a nebulizer employed in a commonly-used plasma mass analytical apparatus or plasma atomic emission analytical apparatus, the flow rate of a gas normally ranges from 0.5 L/min. to 1.4 L/min. It is therefore necessary to set the total volume defined between the tube and the orifice to a range from 1.8×10 6 to 7.1×10 6 μm 3 . Incidentally, the length of the orifice at a portion where the tube and the orifice are closest to each other, may be set to the thickness of the orifice member upon estimating the volume. In the present embodiment, the orifice member comprises a plate having a thickness of 0.2 mm.
An evaluation was performed in a state in which when the thickness t of the orifice member is less than or equal to 1.5 mm, a nebulizer utilizing orifices and tubes of various sizes in combination, was fabricated and installed in an analytical apparatus. The flow rate of a gas introduced into the nebulizer was kept substantially constant. The result thereof is collectively shown in FIG. 3 . An annular sectional area in FIG. 3 corresponds to an annular sectional area of a gas flow in a region in which the tube and the orifice are closest to each other. The annular sectional area={π(D 2 −d 2 )/4} is calculated by using a diameter D of each orifice and a diameter d of each tube. There may be cases where the processing of the orifice is done by a drill and it is performed by the application of a laser beam or by etching. Therefore, the inner diameter of the orifice is not always kept constant depending on processing means or the accuracy of processing in the case of the narrowest region (length t) in which the gas passes through each orifice 4 as shown in FIG. 23 . According to the result shown in FIG. 3, the inner diameter of the narrowest portion through which the gas passes, is defined as D, and a region in which the inner diameter is greater than D by about 20%, is included in a region in which the thickness of the orifice member is t. Data obtained from an example illustrative of a nebulizer in which a satisfactory result was not obtained, are respectively indicated as symbols A and B. In the case of A, an area per spray-gas flow rate equivalent to 1 L/min. is 6.2×10 4 μm 2 . It was revealed that the size of spray was large and the efficiency of spraying was low. If the area is reduced to 3.5×10 4 μm 2 (above B), then the efficiency of spraying is improved and the size of spray becomes much finer. However, if compared with a result placed below a solid line as a result of the execution of evaluation experiments under the installation of a nebulizer satisfying the condition of B in a plasma emission analyzer, then the sensitivity of its analysis was only the half thereof. If the area per spray-gas flow rate equivalent to 1 L/min. is less than or equal to 2.3×10 4 μm 2 , the velocity of the spray gas reaches a supersonic region from the calculation of a slope or inclination of the solid line shown in FIG. 3 . It is desirable that since a processing error of about 10% is not often avoided, the annular sectional area is less than or equal to 2.53×10 4 μm 2 for the purpose of bringing the velocity into the supersonic region. It is necessary to set the entire system to a high-pressure resistant and sturdy one when gas pressure capable of being used for the nebulizer reaches a high pressure of 10 atmospheric pressures or higher. It is desirable that if it is taken into consideration, then the area per spray-gas flow rate equivalent to 1L/min. is set to within a range from 1.8×10 4 to 2.53×10 4 μm 2 .
While a plurality of pieces of tube are used for the supersonic array nebulizer, a problem arises from the practical viewpoint in that there is high possibility that when the inner diameter of each tube 5 is less than or equal to 5 μm, the tube 5 will be clogged with particles such as dust. If the inner diameter is greater than or equal to 200 μm, the efficiency of tearing off the liquid lying in the center of each tube by a gas flow is reduced. As a result, the size of each droplet generated from the nebulizer increases and the spray efficiency of the liquid discharged by spraying is degraded. This is because the more the size of each droplet becomes fine, the more the liquid is easy to be vaporized. Therefore, the inner diameter of each tube 5 needs to fall within a range of 5 to 200 μm in order to obtain the high spray efficiency of the liquid. Further, the spray efficiency of the liquid depends even on the flow rate of the liquid introduced into one tube 5 . It is therefore desirable that the flow rate of the liquid per tube 5 is set to less than or equal to 100 μL/min. Further, the spray efficiency of the liquid discharged by spraying depends on the wall thickness (corresponding to ½ of the difference between the outer diameter and the inner diameter) of each tube 5 . The tube thin in thickness is improved in spray efficiency. While, however, a problem normally arises in terms of the strength if the wall thickness does not reach greater than or equal to 5μ, the spray efficiency is significantly reduced when the wall thickness is greater than or equal to 100 μm. The fixing plate 8 for fixing the position of each tube 5 is disposed at a distance of 1 to 15 mm as viewed from the orifice member 7 . If set to greater than or equal to 20 mm, then the vibration of the tube 5 becomes pronounced and exerts a bad influence on spraying. There is a fear that when less than or equal to 1 mm, the fabrication of the nebulizer becomes difficult, and a pressure loss of the nebulizer gas becomes pronounced because the space defined between the fixing plate and each orifice is small.
In the present embodiment, the orifice member 7 is provided with the three orifices. The holes equal to the same number as above are defined in the fixing plate 8 . Each tube 5 is a molten silica capillary (flow path) whose outer diameter, inner diameter and length are respectively 127 μm, 50 μm and 80 mm. The three orifices 4 whose diameters are 170 μm, are defined in a disk 7 comprised of a stainless material whose surface having a thickness of 0.2 mm is subjected to corrosion-resistant coating and provided at the apexes of a triangle at 2-mm equal intervals. The distance between each orifice 4 and the fixing plate 8 is 5 mm. A tip or a leading portion or end of the second member is cylindrical and has an outer diameter of 9 mm. The leading end thereof is inserted into a cover provided with a seal O-ring for a spray chamber cover to thereby connect the nebulizer and a spray chamber to each other.
FIG. 4 shows the dependence of each signal intensity obtained by the plasma atomic emission analytical apparatus on each sample flow rate. If the spray efficiency is constant, then the sample flow rate and the signal intensity should be brought to a proportional relationship. However, since the spray efficiency is reduced as the sample flow rate increases in practice, the proportional relationship tends to disappear. Even if a sample flow rate of a glass concentric nebulizer is increased to 300 to 400 μL/min., the signal intensity (sensitivity of analytical apparatus) does not increase so far. Particularly when the sample flow rate is 400 μL/min. or more, the signal intensity little increases. On the other hand, when the sample flow rate is 300 μL/min. or less, spraying becomes unstable and the analysis thereof becomes difficult. While a sonic spray nebulizer is capable of spraying a sample small in flow rate with high efficiency, the signal intensity of the analytical apparatus little increases when the sample flow rate is greater than or equal to 60 μL/min. As a result, a problem arises in that a nebulizer usable for a high-sensitivity analysis does not exist in a sample flow-rate range of 100 to 300 μL/min. as shown in the drawing. When, for example, the flow rate of a liquid in a semi-microcolumn is about 200 μL/min., and the semi-microcolumn is coupled to the upstream side of the analytical apparatus to perform a chemical speciation analysis, the high-sensitivity analysis is actually difficult. When the supersonic array nebulizer is used, the signal intensity significantly increases till an introduced sample flow rate of 300 μL/min. As compared with the glass concentric nebulizer, it is shown that when the supersonic array nebulizer is used, the maximum signal intensity can be increased to about twice. As described above, one nebulizer can cope with an extremely small flow rate to a few hundred μL/min. if the supersonic array nebulizer is used. It has been recognized that when a relative standard deviation (RSD) of each signal intensity is less than or equal to 3%, the analytical apparatus can be used for quantitative analysis. Therefore, a result of stability (RSD) of spraying relative to the liquid flow rate, which has been examined by ten times-continuous measurements, is shown in Table 1. RSD is shown as 2.61 at the maximum with respect to sample flow rates equivalent to 7 to 250 μL/min. This result shows that the nebulizer is sufficiently high in stability within the above flow-rate range and can be used for quantitative analysis.
TABLE 1
Spray Stability (RSD) of Supersonic Array Nebulizer
RSD % Element
Flow rate
(μL/min)
Cr
Mn
Co
Cu
As
Se
7
1.43
1.13
1.74
1.35
1.90
1.25
20
1.84
1.53
1.96
1.28
2.52
2.61
30
0.20
1.00
0.87
0.42
0.44
0.20
60
1.43
1.13
1.74
1.35
2.25
1.25
80
1.97
0.52
0.96
0.38
1.04
0.44
100
1.03
1.55
0.83
0.54
1.55
1.82
150
0.43
0.19
2.09
1.43
0.40
1.67
200
1.77
2.03
1.09
0.16
0.98
1.43
250
0.72
0.88
1.15
0.72
1.24
1.47
Embodiment 2
A schematic diagram of a supersonic array nebulizer based on another embodiment of the present invention is shown (in FIG. 5 ). While a basic structure is provided as shown in FIG. 1, FIG. 5 shows an example in which each orifice 4 makes use of one obtained by slicing a resin tube. FIG. 6 is an enlarge view of each orifice shown in FIG. 5. A plastic tube identical in inner diameter (e.g., 170 μm) to the orifice 4 is cut with a thickness of 0.5 mm, and disks 14 for the resultant three plastic tubes are respectively fit in three holes defined in a leading end of a second member, which in turn are fixed with an adhesive. This corresponds to an orifice member whose diameter is 170 μm and whose thickness is 0.5 mm. The three orifices are provided at the apexes of a triangle at 4-mm equal intervals.
Embodiment 3
FIGS. 7 and 8 are respectively enlarged views of orifices of the supersonic array nebulizer based on another embodiment of the present invention. A basic structure of the nebulizer is similar to the embodiment shown in FIG. 5 but an orifice member 7 is fabricated with a ceramic material. A ruby orifice material 15 (whose diameter and thickness are 2 mm and 0.3 mm respectively) having orifices each having an inner diameter of 170 μm is shown in FIG. 7 . Three disks are respectively fixedly fit in three holes defined in a second member. The three orifices are fixed at 4-mm equal intervals. On the other hand, a large ruby orifice member 16 (whose diameter and thickness are 6 mm and 0.3 mm respectively) is shown in FIG. 8 .
Embodiment 4
In an apparatus for plasma emission analysis and plasma mass analysis, a solution sample is first sprayed by a nebulizer to produce aerosol. Next, the aerosol is introduced into a plasma so as to be brought into atbmization, excitation or ionization, whereby ions or radiation light is analyzed. It is therefore of importance that fine aerosol is produced by the nebulizer and the sample is introduced into the plasma with satisfactory efficiency. Further, the introduction of a large quantity of solvents (molecules) into the plasma might exert a bad influence on the analysis thereof. Thus, there may be cases in which the solvents in the aerosol stand in need of their positive removal. This is because the temperature of the plasma is lowered due to the large quantity of solvents, and the production of molecular ions derived from the solvents and the radiation from solvent molecules cause a reduction in analytical sensitivity. FIGS. 9 and 10 are respectively configurational diagrams of a sample introduction system using the supersonic array nebulizer including a solvent removal process, based on one embodiment of the present invention. A sample solution 17 is introduced into a supersonic array nebulizer 19 by a pump 18 . Therefore, the sample solution 17 is controlled to 5 atmospheric pressures by a pressure-reducing valve or regulator 21 and thereby sprayed by an introduced gas. Two types are considered as a method of removing the solvent molecules in the aerosol. In the solvent removing method shown in FIG. 9, the aerosol is heated and thereby evaporated, followed by separation of the solvent through a membrane. In a spray chamber 22 heated to about 150° C., droplets in the aerosol are fully vaporized and introduced into a membrane separator 24 . The membrane having the property of allowing only the solvents to pass therethrough is used to thereby remove the solvent molecules which interferes with the analysis. The remaining substances to be analyzed are introduced into the plasma together with a carrier gas, followed by atomization and ionization. On the other hand, in the method shown in FIG. 10, a spray chamber 22 is cooled to −5° C. and subjected to evaporation to capture solvent molecules and droplets by the surface of the spray chamber 22 . Owing to this function, the removal of the solvent molecules is implemented.
Embodiment 5
FIG. 11 is a configurational diagram of an inductively coupled plasma mass spectrometry (ICP-MS) system using the supersonic array nebulizer combined with a semi-microcolumn, based on one embodiment of the present invention. A sample solution 17 is subjected to chemical speciation separation or normal chemical separation and concentration by a semi-microcolumn 27 , followed by introduction into a supersonic array nebulizer 19 . Therefore, the solution 17 is sprayed from a gas cylinder 20 through the use of a spray gas (4.5 atmospheric pressures) controlled by a pressure-reducing valve or regulator 21 . Aerosol produced by spraying is introduced into a cooled spray chamber 22 to thereby remove solvents. Thereafter, the remaining aerosol is introduced into a plasma 28 . Analyzed substances ionized by the plasma are fractionated and detected by a mass analyzer 29 . The flow rate of the solution in a semi-microcolumn is normally about 200 μL/min. and a concentric glass nebulizer is not capable of coping with it. The use of the supersonic array nebulizer allows the use of the semi-microcolumn. Owing to such a system, a chemical speciation analysis for, e.g., arsenic, selenium, etc. can be performed, and information about the level of toxicity as well as the total volume of elements can also be obtained. The system is expected to be widely applied in, for example, medical and toxicological fields starting with an environmental field. When the separation of the column is not required, a valve 31 is switched to directly introduce the sample solution 17 delivered by a peristaltic pump 18 into the supersonic array nebulizer 19 as shown in FIG. 11. A spray chamber 22 is cooled to −5° C. by a cooling controller 25 to thereby remove solvents. Analytical sensitivity is improved three times as compared with the use of the normally concentric nebulizer in which the sample flow rate is 400 μL/min.
Embodiment 6
FIG. 12 shows a system in which a large number of semi-microcolumns are coupled to the supersonic array nebulizer based on one embodiment of the present invention. While the separation of the columns normally needs a few minutes to several tens of minutes, the width of the time (bandpeak) required to elute a separated solution is about one minute. Therefore, the simultaneous use of the large number of semi-microcolumns at intervals of several minutes allows the implementation of a high-throughput analysis.
Embodiment 7
FIG. 13 is a diagram showing an inductively coupled plasma mass spectrometry system using the supersonic array nebulizer based on another embodiment of the present invention. A three dimensional quadrupole (quadrupole ion trap) mass analyzer 34 is used as a mass analytical apparatus. A mass analytical unit comprises a pair of bowl-shaped end cap electrodes 35 and a doughnut-shaped ring electrode 36 . When a high-frequency voltage V is applied to the ring electrode, ions each having a specific mass number or more are taken in the electrodes according to the applied voltage. After the completion of capturing of the ions, the high-frequency voltage V is scanned from a low voltage to a high voltage to thereby sequentially un-stabilize the ions from the ions each having a low mass number. Thereafter, the ions are discharged outside the electrodes and detected. The mass number of each ion can be determined according to the relationship between the mass number of each detected ion and V. The determination of the quantity of each ion is implemented based on the detected signal intensity. In the present system, a sample solution 17 and solvent (water) 33 are alternately introduced into a supersonic array nebulizer 19 by a flow injection apparatus 32 and sprayed therefrom. Generated aerosol is introduced into a spray chamber 22 . In the spray chamber 22 heated to 150° C. by a heating controller 23 , evaporated water molecules are removed by a separation membrane 24 which allows only water vapor to pass therethrough. The remaining substances to be analyzed are introduced into a plasma (ICP) 28 where they are ionized. The produced ions are introduced into the mass analyzer 34 . The three dimensional quadrupole (quadrupole ion trap) mass analyzer is capable of dissociating molecular ions and removing different types of ions each having the same mass number. Further, a high-sensitivity analysis is realized owing to analyte enrichment based on the three dimensional quadrupole. When the pressure of a spray gas is 4 atmospheric pressures, the flow rate of the spray gas is 1 L/min., and the flow rate of a sample to be introduced is 250 μL/min., the strength of each detected ion is increased to four times as compared with the use of a glass nebulizer in which the flow rate of the sample to be introduced is 400 μL/min.
Embodiment 8
FIG. 14 is a diagram showing an inductively coupled plasma mass spectrometry system for chemical speciation analysis, which uses the supersonic array nebulizer based on another embodiment of the present invention. The present system separates various chemical speciation substances according to capillary electrophoresis (CE) and detects the same by the ICP-MS. A sample containing AsO 2− , AsO 3− , SeO 3 2− , and SeO 4 2− is introduced into three separation capillaries 35 (whose outer and inner diameters are respectively 127 μm and 50 μm) having a length of 30 cm. One end of each capillary 37 is dipped into a buffer solution 38 and the other end thereof is dipped into a conductive auxiliary solution 39 . A voltage of 10 to 25 kV is applied between both ends of each capillary by a high-voltage supply device 40 to thereby realize electrophoresis. The separated sample is introduced into a nebulizer 19 from which it is sprayed. In order to prevent a reduction in high resolution obtained by the electrophoresis, aerosol is directly introduced into a plasma 28 through a connecting tube 41 to perform a sample analysis. In an example experimented under the condition that the buffer solution comprises NaH 2 PO 4 whose concentration is 0.075 mol/L and Na 2 B 4 O 7 (pH 7.65) whose concentration is 0.0025 mol/L, and the applied voltage is 20 kV, the separation and detection of the above components are completed in about 15 minutes since the commencement of the electrophoresis. The limited concentration for their detection is about 0.08 ng/mL.
Embodiment 9
FIG. 15 is a configurational diagram of an inductively coupled plasma atomic emission spectrometry system using the supersonic array nebulizer based on one embodiment of the present invention. A sample solution 17 is introduced into a supersonic array nebulizer 19 by a micro-tube pump 18 . An argon spray gas in a gas cylinder 20 is controlled to 4 atmospheric pressures by a pressure-reducing valve or regulator 21 and supplied to the supersonic array nebulizer. A spray chamber 22 removes slightly large droplets contained in aerosol produced by spraying and discharges them into a waste reservoir 26 . The remaining aerosol is introduced into a plasma 28 . Substances to be analyzed are atomized by the plasma 28 , followed by excitation and light-emission. The emitted light is wavelength-separated by a spectrometer 42 and detected by a detector 43 . A personal computer 30 performs the control of the system and data processing.
A measured result obtained by experiments done under the condition that the pressure of a spray gas is 4.5 atmospheric pressures and the flow rate of the spray gas is 1 L/min., is shown in FIG. 16 . When the flow rate is less than or equal to 250 μL/min., the intensity of a signal increases with an increase in sample flow rate. This trend is a characteristic of the supersonic array nebulizer. While the flow rate is greatly reduced as compared with a flow rate (830 μl/min.) at the time of the use of a concentric glass nebulizer, the sensitivity of the analytical apparatus is improved about twice (wavelengths: Sn 189.989 nm; Cr 205.552 nm; Zn 213.856 nm; Pb 220.353 nm; Cd 228.802 nm; Mn 257.61 nm; Mg 279.553 nm; Cu 324.754 nm). It was also revealed that the supersonic array nebulizer was high in stability as well as compared with the glass nebulizer. When the flow rate of the sample to be introduced is 250 μL/min. and the concentration of an analyzed substance in the sample solution is 1 μg/mL, a relative standard deviation (RSD) obtained by ten times-continuous measurements is less than or equal to 1.5%.
Embodiment 10
FIG. 17 is a configurational diagram of an atomic absorption spectrometry system using the supersonic array nebulizer based on one embodiment of the present invention. In the present example, a supporting gas (air) delivered at several tens of L/min. is used as a spray gas and a solution sample is sprayed therethrough.
As shown in FIG. 17, a spray gas delivered from an air cylinder 44 is depressurized by a pressure-reducing valve or regulator 21 and introduced into a supersonic array nebulizer 45 . A sample solution is introduced into the nebulizer 45 by self absorption and distributed to a plurality of tubes (capillaries) whose ends are inserted into plural orifices. The sample solution is sprayed therethrough by supersonic region supporting gas flows generated form the orifices. A spray chamber 22 removes relatively large droplets contained in aerosol and discharges them into a waste reservoir 26 . A fuel gas delivered from an acetylene cylinder 46 is mixed with the aerosol within the spray chamber 22 and thereafter burned by a burner 47 . In a plasma (acetylene-air flame) 48 exceeding 2000° C., droplets are vaporized and each substance to be analyzed is atomized. A radiation beam emitted from a hollow cathode lamp 49 is applied to the plasma (acetylene-air flame) 48 , whereby the absorbance of the atomized substance to be analyzed is measured by a spectrometer 42 and a detector 43 . As a means or unit for introducing the sample solution, the introduction of it by a peristaltic pump 18 can also be utilized as well as self absorption. The thickness of an orifice member is 1.5 mm. An array nebulizer comprising 16 molten silica tubes (whose inner and outer diameters are respectively 200 μm and 100 μm) and 16 orifices (whose inner diameters are respectively 250 μm) is mounted to a polarized Zeeman atomic absorption spectrometry system and an evaluation experiment was done in this state. As a result, sensitivity similar to the normal nebulizer was obtained even though the flow rate of a sample fluid was 1 mL/min. (⅕ of the normal flow rate). Further, the analytical sensitivity of the atomic absorption spectrometry system was improved about twice as compared with the normal nebulizer from the result that a sample solution delivered at a flow rate of 5 mL/min. has been introduced by the peristaltic pump 18 .
Embodiment 11
FIG. 18 is a cross-sectional view of the supersonic nebulizer based on another embodiment of the present invention. While the present supersonic nebulizer is structurally similar to the nebulizer shown in FIG. 1, the number of spray units is one. However, the present nebulizer is also sprayed through a supersonic region gas. FIG. 19 is an enlarged view of an orifice shown in FIG. 18 . FIG. 20 is similar to FIG. 18 but no fixing plate is used in FIG. 20. A tube 5 is supported by a fixing tube 9 extended to a position away 5 mm from a spray hole or port.
Embodiment 12
FIG. 21 is a cross-sectional view of a supersonic array nebulizer based on a further embodiment of the present invention. A spray gas is introduced through a gas inlet 6 and circulated by a helical gas path. Further, the spray gas is injected from an orifice 4 and reaches a supersonic speed of Mach 1 or more. A sample solution delivered from an end of a tube 5 is sprayed by its supersonic gas flow. The distance between the end of the tube 5 and the outside of an orifice member is less than or equal to 2 mm. Thus, the surface of a liquid is torn off by the velocity of a gas lying in the direction of its injection without reflecting a shock wave of a supersonic gas flow to thereby produce fine droplets.
Embodiment 13
A method of assembling a supersonic array nebulizer based on a still further embodiment of the present invention is simply shown in FIG. 22 . As shown in FIG. 1, the supersonic array nebulizer comprises the first member and the second member. As to an assembly procedure, the supersonic array nebulizer is assembled in accordance with a procedure for fixing each tube 5 to the second member and thereafter coupling it to the first member. In order to fix the position of the end of the tube 5 with respect to an outer surface of an orifice member 7 with satisfactory accuracy, a jig 51 is used in an assembly process. A cylinder having a height of L is provided in the center of the jig. A tip or leading end of the second member is inserted into the jig 51 without any clearance, and the surface of its leading end is brought into contact with the outer surface of the orifice member 7 . As a result, the position of the end of each tube 5 can be brought into contact with the outer surface of the orifice member 7 . When the end of the tube 5 is projected by a constant distance from the outer surface of the orifice member 7 , the height of the cylinder of the jig 51 may be set smaller than L.
A specific assembly process using the jig 51 will be described below. The orifice member 7 is first fixed to the second member with an adhesive 10 . Care is needed so as not to cause the leakage of a gas from a clearance or gap between the orifice member 7 and the second member. Next, a fixing plate 8 is fixed with the adhesive 10 . Thereafter, the tube 5 are inserted into their corresponding orifices 4 and holes defined in the fixing plate 8 , and hence the positions of the tube 5 are determined by the jig 51 . Further, each tube 5 is fixed to the fixing plate 8 with the adhesive 10 . Next, the tubes 5 are inserted into a fixing tube 9 fixed to the first member, and the adhesive is poured into clearances between the tubes 5 and the fixing tube 9 , whereby the first member and the second member are coupled to each other with the screw 3 (see FIG. 1) If they are fixed with the screw 3 before the setting of the adhesive, then the tube 5 is hard to break, thus providing convenience. Finally, the adhesive is buried in the clearance defined between the fixing tube 9 provided outside the first member and each tube 5 to hermetically seal the clearance. Hermetically sealing even both ends of the fixing tube 9 with the adhesive is necessary to prevent a high-pressure gas from leaking.
In the present invention as described above in detail, the spraying of a liquid is efficiently performed using a gas flow lying in a supersonic region. According to an array nebulizer, a sample liquid is divided into a plurality of tubes (capillaries) and introduced therein. Further, the sample liquid is sprayed at ends of the respective tubes through the use of a supersonic gas flow with high spray efficiency. Owing to this function, a reduction in spray efficiency is controlled even in the case of the high flow rate of the liquid. Particularly when it is utilized as a nebulizer for a high-sensitivity analytical apparatus, the sensitivity of the apparatus greatly increases.
While the present invention has been described with reference to the illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to those skilled in the art on reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the true scope of the invention.
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Disclosed herein is a nebulizer capable of performing spraying over a wide flow-rate range from a low flow rate to a high flow rate stably and with high efficiency. Further, the present invention provides a supersonic nebulizer capable of improving the efficiency of spraying by a supersonic region spray gas, and a supersonic array nebulizer wherein a plurality of spray units are placed in array form.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of flame resistant fabric and safety apparel, especially the yarn for high flame resistant safety apparel fabric, cheese dyeing of the yarn, knitting and weaving of the fabric using the yarn as described.
2. Description of the Prior Art
Increased Worldwide Health and Safety working practices have recognized the need for safety apparel for occupational workers from high-risk industries, and have developed a series of FR testing methods and standards that safety apparel should meet such as non-flammable, non-melting, anti-static, arc flame resistant as well as high visibility standards for people working in high risk industries.
SUMMARY OF THE INVENTION
In order to accommodate the requirements above, the present invention manufactures safety apparel using suitable high flame resistant modacrylic/cotton fabrics and high visibility flame retardant modacrylic cotton fabrics that comply with the relevant standards for safety and comfort for the majority of high-risk industrial practices.
In order to achieve the above aim, the present invention uses the following technical process to produce yarn for high flame resistant modacrylic/cotton safety apparel fabric, the yarn containing at least 60% of high flame resistant modacrylic fibers which has LOI (Limiting Oxygen Index) of 32-34%.
The yarn for high flame resistant safety apparel fabrics, is processed by picking→assorting→cleaning→carding→pre-drawing→combing→drawing→roving→spinning→coning→doubling→twisting.
As described, the present invention is used in the body of the yarn for high flame resistant modacrylic/cotton safety apparel fabrics. The yarn also contains combed cotton.
As described, the present invention is used for protective apparel fabrics of high flame resistant modacrylic/cotton yarns containing the following compositions:
1. 60% modacrylic/40% cotton; 2. 60% modacrylic/37%-40% cotton with anti-static blend (anti-static yarn or fibre≦3%); 3. 60% modacrylic/35% cotton/5% nylon; 4. 60% modacrylic/32-35% cotton/5% nylon with anti-static blend (anti-static yarn or fibre≦3%); 5. 60% modacrylic/30-32% cotton/5% nylon/3-5% aramid; 6. 60% modacrylic/29-32% cotton/5% nylon/3% aramid with anti-static blend (anti-static yarn or fibre≦3%); 7. 100% modacrylic
At present the yarn invented for high flame resistant woven safety apparel fabric has a count of 20S/2-45S/2, the twist is 77.5-86.67 T/10 CM, and S twist; the yarn count for knitted fabric is 10S-40S, twist is 56-66 T/10 CM, and Z twist.
The invention includes a cheese dyeing method for the yarn described, the dyeing procedures are as follows:
Grey yarn→coning→loading→pre-processing→dyeing→post-processing→hydro extraction→drying→coning dyed yarn→packaging;
Pre-processing includes kier boiling with wetting agent and alkaline powder;
There are two stages in the dyeing process, the first stage is to dye the modacrylic fiber with cationic dyes, the second stage is to dye the cotton fiber with reactive dyes (where there is a cotton blend).
Dyes and chemicals used to color the invention of high flame resistant yarn for fluorescent yellow are:
The Cationic dyes used are:
Cationic Y10GFF: 0.6-0.8%;
Cationic Y7GL: 0.005-0.01%;
The dye method auxiliaries for the modacrylic dyeing are:
Acetic acid, 0.2-0.5 g/L;
Leveling agent 0.2-0.5 g/L;
Reactive dyes used are:
Reactive dye YHD-8GL: 0.3-0.6%;
Reactive dye TBG190: 0.0005-0.002%;
The dye method auxiliaries for the cotton dyeing are:
Sodium chloride: 30-50 g/L;
Sodium carbonate 10-30 g/L;
Dyes and chemicals used to color the invention of high flame resistant yarn for fluorescent orange:
The Cationic dyes are:
Cationic 10GFF: 0.4-0.7%;
Cationic 5GN: 0.05-0.085%;
The dye method auxiliaries for the modacrylic dyeing are:
Acetic acid: 0.2-0.5 g/L;
Leveling agent: 0.2-0.5 g/L;
The reactive dyes used are:
Reactive CF-GN: 2-2.8%;
Reactive HD-8GL: 0.15-0.25%;
The dye method auxiliaries for the cotton are:
Sodium chloride: 30-50 g/L;
Sodium carbonate 10-30 g/L;
Dyes and chemicals used to color the invention of high flame resistant yarn for black are:
The Cationic dyes used are:
Cationic Y x-GL: 0.6-0.8%;
Cationic R x-GRL: 0.1-0.5%,
Cationic B x-BL: 0.7-0.9%;
Dye method auxiliaries for the modacrylic are:
Acetic acid: 0.3-0.5 g/L;
Leveling agent: 0.3-0.5 g/L;
Reactive dyes used are:
Reactive Y M3R150%: 0.2-0.6%;
Reactive R 3BNJ: 0.1-0.4%;
Reactive B KG: 10-20%;
Dye method auxiliaries for the cotton are:
Sodium chloride: 50-80 g/L;
Sodium carbonate: 10-30 g/L;
Dyes and chemicals used to color the invention of high flame resistant yarn for navy blue are:
The Cationic dyes used are:
Cationic Y x-GL: 0.2-0.4%;
Cationic R x-GRL: 0.1-0.5%;
Cationic B x-BL: 1-2%;
Dye method auxiliaries for the modacrylic are:
Acetic acid: 0.3-0.5 g/L;
Leveling agent 0.3-0.5 g/L;
Reactive dyes used are:
Reactive Y M3R150%: 0.3-0.6%;
Reactive R 3BNJ: 0.4-0.8%;
Reactive B KG: 1-2%;
Dye method auxiliaries for the cotton are:
Sodium chloride: 50-80 g/L;
Sodium carbonate: 10-30 g/L.
The invented dye method for the high flame resistant yarn follows the following procedure:
Step 1—dye the modacrylic fibers with cationic dye: dissolve the cationic dye in hot water heat to 70° C., then add the cationic dye auxiliaries, running 5-10 min, then raise bath temperature to 100° C. at 1° C./minute, hold temperature at 100° C. for approximately 60 minutes, then slowly cool down at 1° C./minute to about 60° C. with cold water, hold temperature at 60° C. for approximately 30-40 minute, take a sample to approve the modacrylic color, rinse loose dye:
Step 2—dyeing the cotton fibers with reactive dyes: pour dissolved reactive dyes and Sodium carbonate powder into the bath, adjust pH value to 9, raise the temp to 60° C., hold temp at 60° C. for approximately 30 minutes, add sodium chloride and sodium carbonate step by step, until the pH value is 4-9, fix the color by holding for 30 min, take sample to approve color; rinse loose dye on the fiber surface with soaping agents.
The present invention provides a dyed yarn through cheese dyeing described as above. The present invention also provides a high flame resistant modacrylic/cotton safety fabric made from the yarn described above. Weaving process of the yarn described, including twisting antistatic filaments with the dyed yarn. The fabrics comply with EU Eco-textiles OKO-TEX STANDARD100 standard; meet the EU flame retardant standard EN11612 and EN11611; comply with EU Standards Institute of EN471 standard for high-visibility safety apparel, and EU EN1149 standard for antistatic; They also meet standards of American Society for Testing and Materials flame retardant textiles ASTM F-1506, and/or American National Standards Institute (ANSI)/ISEA-107 standard for high visibility safety apparel.
Finally, the present invention also provides safety apparel made of high flame resistant fabric as described above.
Compared with the existing technology, the yarn as described in the invention used for high flame resistant safety apparel fabrics uses modacrylic or modacrylic fiber blends with combed cotton and other fibers to obtain strength and high flame resistant properties; uses the cheese dyeing method described in the present invention achieves the required color fastness; twists antistatic filaments with dyed yarn, then weaves the twisted yarn into fabric, the antistatic property of fabric are improved; safety clothing made with this fabric will not continue to burn after leaving a naked flame, it will not melt, it will not drip.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
DETAILED DESCRIPTION
In order to better illustrate the present invention, connection with the embodiment examples below for further explanation.
The production of high fire-resistant safety apparel fabrics including fiber selected, the spinning process, the cheese dyeing process and the weaving process.
1. The Fiber Selected
The present invention uses high flame resistant modacrylic fiber that is produced by the Fushun Ruihua Fiber Company, the specification is 1.5 D/TEX*38 MM. During the production process, antimony pentoxide colloid and dimethylformamide aqueous are added in the polymerization dope, after sufficient mixing, the antimony and chlorine in the copolymer become the important component of the modacrylic fibre which also give it the flame resistant property. Limiting Oxygen Index of this fiber can be varied from 28-34%, but for making protective clothing, fibers of high Limiting Oxygen Index of 32-34% must be chosen to meet the relevant requirements.
2. The Spinning Process
The static of the modacrylic fiber makes the spinning more difficult. Therefore, spinning oil is needed in the pretreatment procedure. After the spinning, oil is widely applied under certain a humidity, the fiber should be covered for 24-48 hours before the start of the spinning process. However, due to the application the spinning oil may affect the fiber absorbancy and make the fiber difficult to dye, this spinning oil must be easy to emulsify, easy to wash, and have low viscosity. Otherwise it will lead to roller contamination in the spinning process and affect the quality of the yarn.
Standards Fabric WeightWoven Fabric WeightKnitted
Breaking Strength Tear Strength Bursting Strength
ASTM F1506 3-5.9 oz/y2 134 min, N 11 min, N 3-8 oz/y2 179 min, N
6-8.4 oz/y2 179 min, N 18 min, N 8.1-16 oz/y2 268 min, N>8.5 oz/y2 223 min, N 22 min, N
EN11611 NA 400N 20N NA 2000N/M 2
EN11612 NA 300N 15N NA 2000N/M 2
EN471 NA 400N 25N NA 8000N/M 2
Secondly, the European Union and the United States Association of flame retardant textiles have strict requirements for flame retardant clothing strength, Therefore, high quality combed cotton must be used to ensure that the yarn strength meets the relevant standards.
Furthermore, for fabric needing a higher strength and thermal protection requirement, 5% nylon and/or 3-5% aramid fibers can be added to improve wear resistance and thermal protective performance.
For fabric with an antistatic requirement, 3% Belltron® antistatic staple fiber (3D-51-638 or 3D-76-B31) can be blended. This can also be achieved by twisting Belltron® (22T-3-B68 or 22T-3-9R1) antistatic filament yarn with it.
The present invention uses yarn containing at least 60% of high flame resistant modacrylic fibers, after blending with different fibers for different end use requirements, the composition of the yarn could be as follows:
1) 60% modacrylic/40% cotton; 2) 60% modacrylic/37% cotton with anti-static blend (anti-static yarn or fibre≦3%); 3) 60% modacrylic/35% cotton/5% nylon; 4) 60% modacrylic/32-35% cotton/5% nylon with anti-static blend (anti-static yarn or fibre≦3%); 5) 60% modacrylic/30-32% cotton/5% nylon/3-5% aramid; 6) 60% modacrylic/27-32% cotton/5% nylon/3-5% aramid with anti-static blend (anti-static yarn or fibre≦3%); 7) 100% modacrylic
The yarn count and the yarn twist above should meet the following requirements:
Yarn count for woven fabric varies from 20S/2 to 45S/2, twist of yarn for woven fabric is 77.5-86.67 T/10 CM, and twist direction is S twist.
Yarn count for knitted fabric varies from 10S to 40S, twist of yarn for knitted fabric is 55-66 T/10 CM, and twist direction is Z twist.
The twist of the yarn is adjusted according to the thickness of the yarn count.
The yarn spinning process including picking→assorting→cleaning→carding→pre-drawing→combing→drawing→roving→spinning→coning→doubling→twisting steps.
3. Cheese Dyeing Process
The European Union and the American Association of flame retardant textiles and National Standards Institute have high requirements for color fastness of the flame resistant and high visibility safety apparel, including washing fastness, staining fastness, wet/dry rubbing fastness, color fastness to perspiration should be no less than grade 4-5, so we use the bobbin dyeing to meet the standard.
The bobbin dyeing process: grey yarn→pine coning→(chamfer)→load yarn→(compress yarn)→(pre-treatment)→dyeing→post processing→dehydration→drying→(coning)→packaging
(1) Grey Yarn
The grey yarn should be checked for appearance, strength and composition before dyeing.
(2) Coning
The diameter of winding (diameter should be ≦17 CM), tightness, density (0.35≦D≦0.38) are decided according to different requirements. These machines can bulk up the fiber for dyeing. It can reduce dye time and improve efficiency. The dye house laboratory provide lab dips for approval prior to bulk production.
(3) Chamfering
For atmospheric type yarn dyeing, yarn density of bobbin at both ends of the outermost (the cheese shoulder) is high, but dye flow is less. To ensure the invariant flow of dye, the hard shoulder should be chamfered round to reduce the density of the shoulder. For high pressure dyeing, chamfering is not a requirement.
(4) Loaded Yarn
Bobbins are loaded into the dye vessel according to required optimum batch size and given a batch number. The dye vessel is then closed and sealed appropriately.
(5) Pressing the Yarn
For high pressure dyeing, compress 5%-30% of the total height of cheese, as a whole, ensure each dye column compression rate is consistent to achieve the same yarn density.
(6) Pre-Treatment
For modacrylic/cotton yarn, the pre-treatment is primarily washing away the oils added in the spinning process, as well as grease, dust and any other contaminants. Oils are essentially removed as they can contain emulsifying agents and antistatic properties that will resist dye and cause poor color fastness and unlevel dye on the surface of the yarn.
Wetting agent and soda powder is used for kier boiling in the pre-treatment procedure to remove the oil and other impurities on the surface of the yarn, to give the yarn more luster after cheese dyeing and to improve color clarity.
Pretreatment requires the use of 3 g/L of soda powder, 2 g/L refined enzyme, 0.5 g/L wetting agent, at 90° C., the bath ratio of 1:10, kier boiling for 10 min.
(7) Dyeing
The invention can be used to dye 100% high flame resistant modacrylic yarn and modacrylic blended yarn. Different colors can be dyed, such as high visibility fluorescent yellow, fluorescent orange, yellow, red, orange, blue and etc. Different compositions have different dyeing orders. Two-batch dyeing for cationic dyes and reactive dyes can prevent residual dye in the bath.
Modacrylic dyeing principle: modacrylic-COOH+H+modacrylic-COO- − +H++D+modacrylic-COOD
Modarylic dyeing is cationic dye. Dyeing modacrylic is a combination of salt link, hydrogen link and ionic link.
First Step—Dye Modacrylic Fiber
a) fluorescent yellow dyeing recipe:
Cationic Y10GFF: 0.6-0.8%;
Cationic Y7GL: 0.005-0.01%;
Acetic acid: 0.2-0.5 g/L;
Leveling agent 0.2-0.5 g/L;
b) fluorescent orange dyeing recipe:
Cationic 10GFF: 0.4-0.7%,
Cationic 5GN: 0.05-0.085%;
Acetic acid: 0.2-0.5 g/L;
Leveling agent: 0.2-0.5 g/L;
c) other color dyeing recipe:
Cationic dyes: X1%;
Acetic acid: 0.2-0.5 g/L;
Leveling agent: 0.3-0.5 g/L;
After the cationic dye is dissolved and heated to 70° C., add auxiliaries to the dye bath, run 5˜10 min, the bath temperature is raised to 100° C. at 0.5° C. a minute and held for 60 minutes. Cooled the bath to about 60° C. with cold water at 2 degrees a minute, a color sample is then taken for approval. Rinse to remove the loose dye and ensure good color fastness.
B. Second Step—Dye Cotton Fibers
a) fluorescent yellow dyeing recipe:
Reactive dyes YHD-8GL: 0.3-0.6%;
Reactive dye TBG190: 0.0005 to 0.002%;
Sodium chloride 30-50 g/L;
Sodium carbonate 10-30 g/L;
b) fluorescent orange dyeing recipe:
Reactive CF-GN: 2-2.8%;
Reactive HD-8GL: 0.15-0.25%;
Sodium chloride: 30-50 g/L,
Sodium carbonate 10-30 g/L.
c) other color dyeing recipe:
Reactive dyes: X2%;
Sodium chloride: 50-80 g/L;
Sodium carbonate: 10-30 g/L;
Pre-dissolved reactive dye and anhydrous sodium carbonate are added to the bath, to adjust the pH value to 9. Raise the temperature to 60° C., and hold for 30 min. Evenly add sodium chloride and sodium carbonate and control the pH value between 4-9. Once the pH is correct, hold for a further 30 minutes. Then take color sample again to confirm the color. Once color has been approved the bath is rinsed several times with soap and water. This removes any surface dye and ensures good color fastness. The color fastness is then checked. Thereafter soft finishing is applied to ensure good “handle”.
(8) Hydro Extraction
To remove excess water after dyeing, the Cones are placed evenly in a high speed centrifuge for approximately 10 minutes to reduce water content to 45%. This improves drying time and efficiency.
(9) Drying
Drying has to be carried out at the correct speed. If the speed is too slow, the drying time will be too long, and can cause yarn discoloration; if the speed is too fast, the yarn moisture will be too high to make rewinding difficult. RF drying speed is 6 m/h, after being left for 24 hours to condition. Check the yarn color, color fastness, strength and bobbin uniformity after drying. After completion of inspection, the yarn is rewound with equal and low tension, slow speed.
4. The Weaving Process
Fabric for safety apparel is monitored by strict requirements for tear strength, breaking strength, bursting strength, seam strength. This can also be achieved by controlling the weight of the fabric. Before weaving the fabric, a suitable fabric weight should be designed to comply with the requirements of different levels of safety clothing.
For fabric with antistatic requirement, there are basically four types of methods:
a. adding antistatic additive; b. blend antistatic staple fiber while spinning the yarn; c. weave the antistatic filament yarn at the back of the fabric; d. twist the antistatic filament yarn with the colored yarn and weave into the fabric;
For the first method, the antistatic properties will slowly disappear after several washes;
For the second method, the costs are high and uneconomic;
For the third method, antistatic filaments are easily exposed and destroyed after washing and with contact with the inner garment lining or skin.
The weaving process of the present invention is the fourth method stated above. By twisting the antistatic filament with the dyed yarn, then weaving the twisted yarn into the fabric, the antistatic properties will not be affected by repeated washes, the antistatic filament is not easily exposed, and the performance and comfort of the fabric is maintained.
Weaving methods of the present invention, the woven fabric and knitted fabric weaving processes are as following.
A: Woven Fabric
1. Weaving Processes
Twist dyed yarn with antistatic filament→drawing-in→healding→reed-in→test weaving→dropper pinning→discharge fabric→inspect the grey fabric.
2. Finishing Process
Finishing process include: Washing→Heatsetting→Sanforizing
Washing: 80° C. wash with soap, then hydro extraction.
Heatsetting:
feed fabric→dewing→cylinder roller drying—stenter drying→discharge of the fabric.
Oven temperature: 170° C., speed: 36 m/min.
Pre-Shrinking Process:
feed fabric→steam damping→Rubber coated compression rollers with adjustable pressure→discharge of the fabric→inspection→roll the fabric.
The rubber pressure: 3 KG, speed: 30 m/min, temperature: 80° C.
B: Knitted Fabric
1. Knitting Process:
Twist dyed yarn with the antistatic filament→put the yarn ball into the shack→yarn tensioner→yarn feeding→midway tensioning→yarn-feeding→discharge fabric→fabric fed into the cloth rack→roll the fabric.
Various specifications of finished knitted fabric are as below:
a. Pique fabric weight: 210-280 gsm, Width: 200-220 cm, yarn Count: 18-20 s/l. b. fleece fabric weight: 300-450 gsm, width: 180 cm Yarn: 10-20 s/l. c. rib fabric weight: 210-500 gsm, width: 170 cm Yarn: 10-32 s/l. d. single jersey fabric weight: 210-250 gsm width: 180 cm Yarn: 18-20 s/l.
2. Finishing Process:
Washing→setting
Washing process: color fabric washing; water temperature around 60-70° C., add detergent 209 of 2%, washing about 15-30 min→Rinse with water (once)→Rinse with water again with softener (1-2%)→Hydro extraction→tumble dry.
After relax drying, the fabric is prepared for heat setting, the stenter temperature is 150-160° C., width of stenter is set (the width of the fabric 2-3 cm wider than the finished fabric), warp overfeed (2 to 4%). Overfeed size will ensure the required gsm, improve fabric shrinkage→enter the pin frame, the setting speed 30 seconds→cooling temperature <50° C.→inspection→roll the fabric.
The finished woven and knitted fabrics are used to make safety work wear (in fluorescent yellow, orange or other solid colors) including coverall, jacket, trousers, shirt, polo shirt, sweat shirt, thermal under wear, vests, hoods, etc. The designs of the work wear made from the invention are to conform to relevant requirements for flame retardant clothing of Unites States of America for personnel working in a potentially hazardous environment.
Unless otherwise noted, the dye content and yarn content in the embodiment refers to is the weight percentages.
EXAMPLES
Example 1—Fluorescent Yellow 60% Modacrylic/40% Combed Cotton
Use 60% high flame resistant modacrylic, 40% combed cotton through picking→assorting→cleaning→carding→pre-drawing→combing→drawing→roving→spinning→coning→doubling→twisting steps, make the modacrylic/cotton grey yarn.
Cheese dyeing the yarn, through pine coning→loading yarn→pre-treatment→dyeing→post processing→hydro extraction→drying→coning→packaging steps; pre-treatment use wetting agent and soda powder for the kier boiling. That is yarn in the 3 g/L of soda powder, 2 g/L refined enzyme, 0.5 g/L wetting agent, at 90° C., the liquor ratio of 1:10, kier boiling for 10 min.
Dye the modacrylic fiber: dissolve the cationic Y10GFF 0.7% and Y7GL 0.006% and heat to 70° C., adding acetic acid (0.2-0.5 g/L) and leveling agent (0.2-0.5 g/L) to the dye bath, run 5˜10 min, the bath temperature is heated to boiling at a rate of 0.5° C. per minute, then the temperature is held for 60 min, then the bath is cooled to about 60° C. with cold water slowly at a rate of 1° C. per minute. After 30 minutes the dyeing of the modacrylic is complete. A color sample is taken for shade approval. Rinse to remove the loose dye and ensure good color fastness.
Then dye the cotton fiber, adding the pre-dissolved reactive dye YHD-8GL 0.5% and TBG190 150% of 0.0005%. and anhydrous sodium sulfate, to adjust the pH=9, the temperature is raised to 60° C., the temperature is held for 30 min. Add sodium chloride and sodium carbonate, make pH value to 4-9, after about 30 min a sample is taken for color approval. Then make several rinses with soap to remove any surface loose color. Unload and prepare for drying after hydro extraction.
Example 2—Dye Fluorescent Orange 60% Modacrylic/40% Combed Cotton Yarn
Use 60% high flame resistant modacrylic, 40% combed cotton, through picking→assorting→cleaning→carding→pre-drawing→combing→drawing→roving→spinning→coning→doubling→twisting steps make out the modacrylic/cotton grey yarn.
Then cheese dyeing the yarn, including grey yarn→pine coning→load yarn→pre-treatment→dyeing→post processing→hydro extraction→drying→coning→packaging steps; Use wetting agent and soda powder for pretreatent kier boiling. That is yarn in the 3 g/L of soda powder, 2 g/L refined enzyme, 0.5 g/L wetting agent, at 90° C., the liquor ratio of 1:10, kier boiling for 10 min.
Then dye the modacrylic fiber: dissolve the cationic 10GFF 0.4˜0.7% and 5GN 0.05˜0.085% and heat to 70° C., add acetic acid (0.2-0.5 g/L) and levelling agent (0.2-0.5 g/L) to the dye bath, run 5˜10 min, the bath temperature is heated to boiling at a rate of 0.5° C. per minute and held for 60 min, then the bath is cooled to about 60° C. with cold water slowly at a rate of 2° C. per minute, A color sample is taken for shade approval. Rinse to remove the loose dye and ensure good color fastness.
Then dye the cotton fiber, adding the pre-dissolved reactive dye CF-GN 2˜2.8% HD-8GL 0.15˜0.25%, and anhydrous sodium sulfate, to adjust the pH value to 9. The temperature is raised to 60° C. and is hold for 30 min, Add sodium chloride and sodium carbonate (45 g/L), to make pH value to 4-9 after about 30 min a sample is taken for color approval. Then make several rinses with soap to remove any surface loose color. Unload and prepare for drying after hydro extraction.
Example 3—Black 60% Modacrylic/35% Combed Cotton/5% Nylon Yarn and make the 8.8 oz/yard2 Antistatic Fabric
The dyeing process is nearly same as example 1. But as the yarn is spun from 60% modacrylic and 40% combed cotton, the cationic formulations to dye the modacrylic fiber are as follows: Y x-GL 0.6-0.8%, R x-GRL 0.1-0.5% and B x-BL 0.7-0.9%, acetic acid 0.3 g/L and leveling agent 0.3 g/L. At the same time, add alkyl phosphate 0.3 g/L and LG 0.08%˜˜1%, anti-precipitant agent 0.3 g/L to dye the nylon.
The reactive dye formulations to dye the cotton fiber are as follows: Y M3R150% 0.2-0.6%, R 3BNJ 0.1-0.4% and B KG 10-20%, sodium chloride 70 g/L, sodium carbonate 20 g/L.
Twist the black yarn with antistatic filament (Belltron® 22T-3-B68 or 22T-3-9R1). Make the black woven antistatic fabric by using 32 s/2 yarn by 109*62/in and on every 1 cm, add one twisted antistatic yarn.
Example 4—Dark Blue Color 100% Modacrylic Yarn
The dyeing process is nearly same as example 1, but as the yarn is spun from 100% modacrylic fiber, the formulations to dye the modacrylic fiber are as follows: Y x-GL 0.2-0.4%, R x-GRL 0.1-0.5% and B x-BL 1-2%, acetic acid 0.5 g/L and leveling agent 0.3 g/L.
Example 5—Dark Blue Color 60% Modacrylic/40% Cotton with Antistatic Blend Jersey Fabric
The dyeing process is nearly same as example 1, but the yarn is spun from 60% modacrylic and 40% combed cotton, the cationic formulations to dye the modacrylic fiber as follows: Y x-GL 0.2-0.4%, R x-GRL 0.1-0.5% and B x-BL 1-2%, acetic acid 0.5 g/L and leveling agent 0.3 g/L.
The reactive dyes formulations to dye the cotton fiber as follows: Y M3R150% 0.3-0.6%, R 3BNJ 0.4-0.8% and B KG 1-2%, sodium chloride 70 g/L, sodium carbonate 20 g/L.
Twist the dark blue yarn with antistatic filament (Belltron® 22T-3-B68 or 22T-3-9R1). Adding the yarn into the jersey fabric at 0.5 cm intervals.
Final in house and independent testing of the above high flame resist fabrics ensures that cotton color fastness, washing fastness, staining fastness, wet/dry rubbing fastness, perspiration fastness meets the grade 4-5 requirements;
Safety apparel made from the fabric described in the present invention comply with the EURO textile OKO-TEX STANDARD100 standards; meets EU flame retardant textiles EN11612, EN11611 standard; complies with EU Standards Association for high visibility safety clothing EN471 standard and antistatic EN1149 standards; complies with the U.S. Testing and Materials, flame retardant textiles ASTM F-1506 standard, and American National Standards Institute high visibility safety apparel (ANSI)/ISEA-107 standard.
Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.
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The present invention relates to flame retardant fabrics and safety apparel, especially yarn used for high flame resistant safety apparel fabric wherein the yarn uses a cheese method and the yarn is used to weave fabric. The fabric as described contains at least 60% high flame resistant modacrylic fiber which after cheese dyeing is woven into fabric. The safety apparel that use this fabric will not continue to burn after leaving a fire, will not melt or cause the wearer secondary injury and complies with the relevant standards of the European Union, the United States and China.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of U.S. Pat. No. 6,988,920 filed on Mar. 11, 2004, which is a continuation-in-part of U.S. Pat. No. 6,955,576 filed on Mar. 13, 2003, which is a continuation-in-part of U.S. application Ser. No. 10/040,404 filed on Jan. 9, 2002, now abandoned.
BACKGROUND OF INVENTION
[0002] 1. Field of Invention
[0003] This invention relates generally to a slider, used for sliding on snow, grass, sand or the like. The slider is a foam core to which layers are laminated to protect against erosion, wear and ultraviolet light. In the context of this specification, the slider is anyone of the embodiments. The slider is a bodyboard, a snow board, a snow sled, a grass sliding board, a sand sliding board, a surfing board or the like.
[0004] 2. Related Prior Art
[0005] The slider of the prior art is a board made of plastic that has handles attached on the surface of the board and has a design printed in a central area of the board. The plastic is typically a hard plastic in order that the board could be wear resistant. However, the solid plastic board is generally not comfortable for the user and the board is also heavy for the users, especially children to carry. Besides, the design simply printed on the surface of the board is easily worn off due to the frequent contact with the user.
[0006] Another slider of the prior art is a board made of expanded foam. An outer film is generally laminated to a top surface of the foam board and several strips are laminated to edges of the foam board. The slider made of foam is more comfortable for the users to contact with and lighter for the users to carry with than a slider made of solid plastic. However, It is known that the ultraviolet damages of expanded foam; furthermore, the outer film and the strip also degrade under the sunshine after a period of time. Air-cells of the foam board fracture when abraded. Once the air-cells are broken, water retains in the open cells and erosion reduces the life of the slider. Furthermore, the design of a slider mostly is printed on the outer film and the strips; therefore, the design on the board deteriorates very quickly.
[0007] The designs or patterns on the sliders are convenient means for the owners to identify their sliders. Therefore, an enduring pattern of the slider performs a useful and decorative function.
SUMMARY OF INVENTION
[0008] It is a primary object of the invention to provide a slider whose surfaces resist accelerated erosion due to moisture, dirt and ultraviolet sunlight.
[0009] It is another object of the invention that a pattern imprinted on the slider resists wear and tear.
[0010] Another object of the invention is that the slider is comfortable to the touch.
[0011] In one embodiment, this invention discloses a slider comprising a foam core, a top layer, a pattern, and a bottom layer. The foam core has a top surface, a bottom surface and edge surfaces. The top layer is a composite layer heat laminated to the top surface and edge surfaces of the foam core. The pattern is formed within the top layer and is visible from outside of the top layer. The bottom layer is heat laminated to the bottom surface of the foam core.
[0012] In another embodiment, the top layer of this invention comprises an outer film, an inner film, a pattern, and a foam skin. The outer film has a top surface and a bottom surface on which the pattern is printed. The inner film has a top surface heat laminated to the bottom surface of the outer film and a bottom surface which is heat laminated to a top surface of the foam skin. A bottom surface of the foam skin is heat laminated to the top surface and edge surfaces of the foam core.
[0013] In a further embodiment, the bottom layer of this invention comprises a foam skin and a plastic board. The foam skin has a top surface, which is heat laminated to the bottom surface of the foam core and a bottom surface, which is heat laminated to the plastic board. The plastic board is a composite board and a pattern is printed within the plastic board.
[0014] Other features of the invention include bonding films that enable foam materials such as polystyrene to be heat laminated to polyethylene.
BRIEF DESCRIPTION OF DRAWINGS
[0015] The invention will be more clearly understood after referring to the following detailed description read in conjunction with the drawings wherein:
[0016] FIG. 1 is an exploded perspective view of a slider according to a first embodiment of the present invention;
[0017] FIG. 2 is a cross sectional view of the slider of FIG. 1 ;
[0018] FIG. 3 is a regionally enlarged cross sectional view of the slider of FIG. 2 ;
[0019] FIG. 4 is a cross sectional view of a slider according to a second embodiment of the present invention;
[0020] FIG. 5 is a cross sectional view of a slider according to a third embodiment of the present invention;
[0021] FIG. 6 is a cross sectional view of a slider according to a fourth embodiment of the present invention;
[0022] FIG. 7 is a cross sectional view of a slider according to a fifth embodiment of the present invention;
[0023] FIG. 8 is a cross sectional view of a slider according to a sixth embodiment of the present invention;
[0024] FIG. 9 is a cross sectional view of a slider according to a seventh embodiment of the present invention; and
[0025] FIG. 10 is a cross sectional view of a slider according to an eighth embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0026] With reference to FIGS. 1-3 , a slider in accordance with a first embodiment of the present invention comprises a foam core 1 , a top layer 4 , and a bottom layer 5 . The foam core 1 has a top surface 10 , a bottom surface 11 and edge surfaces 12 . The top layer 4 is heat laminated to the top surface 10 and edge surfaces 12 of the foam core 1 , and the bottom layer 5 is heat laminated to the bottom surface 11 of the foam core 1 . The foam core 1 is made of polyethylene foam and has a density in the range of 1.2 to 8 PCF (pounds per cubic foot) so that the foam core 1 is light and flexible. In the first embodiment, the top layer 4 is a composite layer or a patterned laminate, which includes a first outer film 41 , a first inner film 42 and a first pattern 3 a placed in between the first outer film 41 and the first inner film 42 . Both the first outer film 41 and first inner film 42 are made of plastic. The first pattern 3 a is pre-printed on a bottom surface 412 of the first outer film 41 and is visible from outside of the first outer film 41 . The first inner film 42 has a top surface 421 which is heat laminated to the bottom surface 412 of the first outer film 41 . The first pattern 3 a is thereby protected from direct exposure to the outside of environment. A bottom surface 422 of the first inner film 42 is heat laminated to the top surface 10 and edge surfaces 12 of the foam core 1 . In addition, the first outer film 41 is made of a transparent material so that the first pattern 3 a is visible from outside of the slider.
[0027] A method for making the slider is described as follows: (1) extruding the first outer film 41 with a thickness in the range from 0.02 mm to 0.15 mm by an extrusion machine; (2) printing the first pattern 3 a on the bottom surface 412 of the first outer film 41 using black and white printing or color printing techniques; (3) extruding the first inner film 42 with a thickness in the range from 0.01 mm and 0.15 mm; (4) spreading the molten first inner film 42 on the bottom surface 412 of the first outer film 41 , providing the first inner film 42 not only is heat laminated to the bottom surface 412 of the first outer film 41 but also overlays the first pattern 3 a ; and (5) heating the bottom surface 422 of the first inner film 42 to molten conditions and pressing the top layer 4 to the top surface 10 and the edge surfaces 12 of the foam core 1 . The process of combining the first outer film 41 and the first inner film 42 or combining the first inner film 42 and the foam core 1 is called heat laminating, alternatively heat fusion or heat sealing.
[0028] During the process of combining the top layer 4 and the foam core 1 , the top layer 4 is placed on a hot mold (not shown). The mold surface has a plurality of embossments, when the mold surface covered by the top layer 4 is pressed against the foam core 1 , concaves 40 are formed as shown in FIG. 3 . That is, the first outer film 41 together with the first inner film 42 is embossed to define the concaves 40 in an exterior surface 411 of the first outer film 41 . The concaves 40 are defined to enhance the area of contact between the top layer 4 and the foam core 1 , and thereby increase the strength of the seal of the top layer 4 and the foam core 1 . Furthermore, the concaves 40 enable the users to grab the slider with greater tenacity.
[0029] With reference to FIG. 4 , a slider in accordance with a second embodiment of the present invention includes the entire structure of the FIG. 1 to FIG. 3 , such as a foam core 1 , a top layer 4 and a bottom layer 5 . In this second embodiment, the top layer 4 includes a patterned laminate and a first polyethylene foam skin 43 . The patterned laminate includes a first outer film 41 , a first inner film 42 and a first pattern 3 a placed in between the first outer and inner films 41 , 42 , as disclosed in the first embodiment. The first polyethylene foam skin 43 is interposed between the first inner film 42 and the top surface 10 and edges surfaces 12 of the foam core 1 . In addition, the first polyethylene foam skin 43 has a top surface 431 being heat-laminated to the bottom surface 422 of the first inner film 42 and a bottom surface 432 being heat-laminated to the top surface 10 and edge surfaces 12 of the foam core 1 . The first polyethylene foam skin 43 has a greater density than that of the foam core 1 and has a density in the range of 1.5 to 10 PCF. The first polyethylene foam skin 43 has smoother surfaces due to the lower density, and therefore improves the bonding strength among the high-density the top layer 4 , the first foam skin 43 and the foam core 1 during the heat lamination process when compared to the case when the top layer 4 is directly bonded to the low-density foam core 1 .
[0030] When subject to the heat lamination process, the first pattern 3 a is therefore sandwiched between the first outer film 41 and the first inner film 42 with one side joined to the first outer film 41 and the other side joined to the first inner film 42 . After heat lamination is completed, the pattern 3 a is substantially the same with the one pre-printed on the outer film 41 before the heat lamination process. Thus the slider of the present invention provides a high resolution image thereon.
[0031] FIG. 5 is a slider in accordance with a third embodiment of the present invention, which includes all features of the first embodiment, such as a foam core 1 , a top layer 4 and a bottom layer 5 . In the third embodiment, the bottom layer 5 is a composite layer and comprises a second polyethylene foam skin 51 and a plastic board 52 . The second polyethylene foam skin 51 has a top surface 511 being heat laminated to the bottom surface 11 of the foam core 1 and a bottom surface 512 being heat laminated to the plastic board 52 . The second polyethylene foam skin 51 has a greater density than that of the foam core 1 and has a density in the range of 1.5 to 10 PCF.
[0032] A method for making the bottom layer 5 of the third embodiment is described as follows: (1) extruding the plastic board 52 with a thickness in range from 0.3 mm to 1.5 mm; and (2) spreading the molten plastic board 52 on the bottom surface 512 of the second polyethylene foam skin 51 . Therefore, the plastic board 52 is tightly heat laminated to the second polyethylene foam skin 51 . Thereafter, heating the top surface 511 of the second polyethylene foam skin 51 to a softened state and then laminating the bottom layer 5 to the bottom surface 11 of the foam core 1 . The bottom layer 5 is tightly heat laminated to the polyethylene foam core 1 .
[0033] With reference to FIG. 6 , a slider in accordance with a fourth embodiment of the invention comprises all the elements of the second embodiment. In the fourth embodiment, the bottom layer 5 further comprises a second polyethylene foam skin 51 and a plastic board 52 having a slippery bottom surface for gliding on waters, grounds or snows. The second polyethylene foam skin 51 has a top surface 511 being heat laminated to the bottom surface 11 of the foam core 1 and a bottom surface 512 being heat laminated to a top surface of the plastic board 52 . The second polyethylene foam skin 51 has a greater density than that of the foam core 1 and has a density in the range of 1.5 to 10 PCF.
[0034] FIG. 7 is a slider in accordance with a fifth embodiment of this invention, which comprises all the elements of the fourth embodiment. In the fifth embodiment, the plastic board 52 includes a plastic plate 523 and a patterned laminate having a second pattern 3 b , a second outer film 521 and a second inner film 522 . The patterned laminate of the bottom layer 5 is similar to that of the top layer 4 and is bonded to the bottom surface 512 of the second polyethylene foam skin 51 . Specifically, the second outer film 521 , second inner film 522 and the plastic plate 523 are made of plastic. The second pattern 3 b is printed on a top surface 521 a of the second outer film 521 and is visible from outside of the second outer film 521 . The second inner film 522 has a top surface 522 a being heat laminated to the bottom surface 512 of the second polyethylene foam skin 51 and a bottom surface 522 b heat laminated to the top surface 521 a of the second outer film 521 . The second pattern 3 b is thereby protected from direct exposure to the outside of environment. The plastic plate 523 is bonded to a bottom surface 521 b of the second outer film 521 . In addition, the second outer film 521 and the plastic plate are both made of transparent material so the second pattern 3 b is visible from outside of the slider.
[0035] With reference to FIG. 8 , a slider in accordance with a sixth embodiment of the invention includes a foam core 100 made of non-polyethylene materials, such as polystyrene and polypropylene materials and has a density in the range of 0.8 to 8 PCF. In the sixth embodiment, the slider further includes a top layer 4 , a first bonding film 6 a , a second bonding film 6 b and a bottom layer 5 . Polystyrene is inexpensive and easy to be extruded as the foam core 100 . However, it is difficult to heat laminate polyethylene foam directly onto polystyrene foam. Therefore, the first bonding film 6 a and the second bonding film 6 b are used to overcome the lamination problems. In FIG. 8 , the top layer 4 is heat laminated to the top and edge surfaces of the foam core 100 by the bonding film 6 a . The bottom layer 5 is heat laminated to the bottom surface of the foam core 100 by the bonding film 6 b.
[0036] With reference to FIG. 9 , a slider in accordance with a seventh embodiment of the invention comprises a foam core 1 , a top layer 4 , and a bottom layer 5 . The top layer 4 is heat laminated to the top surface of the foam core 1 and extends around the upper half of the edge surfaces 12 of the foam core 1 . The bottom layer 5 is heat laminated to the bottom surface of the foam core 1 and extends around the lower half of the edge surfaces 12 of the foam core 1 . Therefore, the top layer 4 and bottom layer 5 are sealed together at edges. The structure of the seventh embodiment also applies to the above-mentioned embodiments.
[0037] With reference to FIG. 10 , a slider in accordance with an eighth embodiment of the invention comprises a polyethylene foam core 1 having a density in the range of 1.5 to 10 PCF, a top layer 4 , and a bottom layer 5 . The polyethylene foam core 1 has a top surface 10 and a bottom surface 11 . Both the top layer 4 and the bottom layer 5 are composite layers and the elements of the composite layers are shown in the above-mentioned embodiments. Furthermore, the eighth embodiment comprises two holes 7 defined through the slider for being handhold.
[0038] Accordingly, the top layer 4 and the bottom layer 5 protect the foam core 1 as well as the first pattern 3 a and the second pattern 3 b from erosion by exposure to ultraviolet light, moisture and abrasion. Furthermore, the first and second patterns 3 a , 3 b being visible from outside of the slider that attracts the users attentions.
[0039] The foregoing description is for purposes of illustration only and is not intended to limit the scope of the protection accorded this invention. The scope of protection is to be measured by the following claims, which should be interpreted as broadly as the inventive contribution permits.
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A slider resists erosion due to moisture, dirt and ultraviolet of sunlight and protects a pattern or the bonded surface from wear and tear. The slider contains a foam core, a top layer, a pattern, and a bottom layer. The foam core has a top surface, a bottom surface and edge surfaces. The top layer is a composite layer heat laminated to the top surface and edge surfaces of the foam core. The pattern is formed within the top layer and visible from outside of the top layer. The bottom layer is heat laminated to the bottom surface of the foam core.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a washing machine or a combination wash dryer with an automatic detergent dispensing apparatus and a washwater pump which evacuates the washwater via a drain hose, and with equipment to prevent detergent losses. An advantageous method to control this washing machine is also described.
2. Description of the Prior Art
A longstanding goal of the washing machine industry has been to keep the amount of detergent not used in the washing process as low as possible. A number of different proposals have been made to solve this probem. DE-OS No. 31 06 604 and DE-GM No. 78 13 695 describe arrangements in which there is a so-called float in the washtub drain, which floats upward as a result of the backpressure of the remaining water in the drain hose, and is thereby intended to close the drain opening.
Such closing devices have not been realized in practice, however, since it has proven to be very difficult to achieve a really tight seal at the drain opening. Even a small leak sooner or later leads to an equalization of the remaining water column in the drain hose, i.e. the water gets into the tub and the bouyancy of the hollow body is no longer sufficient to achieve a secure closing of the drain opening. In the subsequent wash cycle, nevertheless, detergent can still get through the drain opening into the sump of the machine, and therefore becomes useless for the washing process.
Another valve configuration for the same purpose is described in DE-PS No. 27 12 093. The flap valve described therein is expensive, and is complicated to install in the washtub drain. Furthermore, lint or similar substances can easily prevent a complete closing.
The prior art also includes an additional reservoir in the drain system of a washing machine, so that there will always be enough water remaining in the drain system to prevent the dispensed detergent from sinking down into the drain.
But even this measure has proven ineffective. The detergent, generally in granular form, still gets into the area of the drain before it is dissolved, and is removed unused during drainage.
Thus all previous efforts to prevent detergent losses in the manner described above have been unsuccessful.
OBJECT OF THE INVENTION
The general object of the invention is to design a washing machine or a comination washer-dryer of the type described above with a closing apparatus which creates a tight seal which operates securely and closes the washtub drain tightly. The object of the invention also includes a suitable process to control this washing machine.
SUMMARY OF THE INVENTION
It has been shown that only by means of the characteristics combined in accordance with the invention can an apparatus be created which can be used in practice, and operates securely to prevent the loss of unused detergent. By means of the additional water reservoir in the drain tube, and by means of the special configuration of the washtub drain, the float advantageously has sufficient bouyancy to work together with the seal arrangement for a secure closing of the washtub drain opening.
The integration of the water reservoir in the anti-return portion of the machine has the advantage that no longer must be an additional part be interposed in the drain hose of the machine. In addition, the water reservoir is advantageously installed inside the machine housing, since such a location prevents manipulations which might otherwise be made on a part located outside the housing, and which might adversely affect the proper operation of the valve apparatus.
On account of the special structure of the float, the penetration of water into its inside is prevented, and more economical materials and fabrication processes can be used for the manufacture of such a float.
Before the beginning of a wash cycle during which detergent will be added, it is appropriate to turn on the washwater pump for a short period of time, to remove any water in the washtub into the drain system. Since under some circumstances, this measure alone is not sufficient, the additional measures described herein produce a further improvement, by means of which the force applied to the float is guaranteed or increased. The can advantageously be achieved by the variants described herein.
Safety precautions should also be taken to prevent an undesired activation of the additional control steps, if such an activation is undesirable for technical reasons.
One embodiment of the invention is illustrated schematically in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a head-on view of a washing machine in simplified form with the elements necessary for the explanation of the invention,
FIG. 2 shows, in simplified form, the drain system of a drum-type washing machine of conventional construction,
FIG. 3 shows the area of the washtub drain opening in cross section, as a detail.
FIG. 4 shows a spherical float with its filler before being joined together, in partial cross section.
FIG. 5 shows a float similar to the one in FIG. 4, in which the filler is formed by the injection of a two-component foam,
FIGS. 6 and 7 show a float, in cross section, with a filler and a coating.
FIG. 8 is similar to FIG. 1, but shows additional elements utilized in preferred embodiments of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The washtub drain (2) in the form of a rubber hose is connected to the washtub (1) of a drum washing machine. The washtub drain (2) consists of the chamber (21) as well as the folding sleeve (22) and is advantageously constructed in one piece. The water is extracted from the washing machine by means of the washwater pump (3) and the drain hose (4). As is well known in the art, and as is shown in FIG. 8, the drum washing machine may also incorporate a spin drum utilized in connection with wash tub (1) which is generally mounted coaxial therewith.
There is a float (5) inside the chamber (21) of the washtub drain (2). In a preferred embodiment, it is designed as a hollow plastic body.
As shown in greater detail in FIG. 3, there is an insert (6) in the tub drain (2). With its circular rim (7), the insert (6) is buttoned into the washtub drain (2). The washtub drain (2) and the insert (6) can be fastened in the conventional manner using clamping rings (8).
The insert (6) has a cylindrical extension (9) which points downward, which provides a tight seat in the elastic tub drain (2).
Fastened to the underside, in the area of the drain opening of the insert (6) is a seal element (10), which exhibits a sealing lip directed inward toward the drain opening. The seal element (10) can be buttoned as shown on the insert (6) in a known manner, however a one-piece embodiment would also be conceivable, where the sealing lip is formed directly on the insert (6).
On the upper side of the insert (6), there is a guide element (11), which has the task of breaking up the sheet of water which may form during the spin cycle, and also makes certain that the detergent dispensed is kept away from the critical region of the drain opening, at least to some extent.
In the drain state, the washwater pump (3) transports the water via the drain hose (4), the anti-return section (13) and the so-called drain elbow (14) into the public sewer system.
The anti-return section (13) is a one-piece plastic part, in which there are passages (15 and 16). On its lower end, the anti-return section (13) has connection pipes (17) for the hoses carrying water, and a connection pipe (18) at its upper end for a ventilation hose. The anti-return section (13) is connected to fastening lugs formed on one inside wall of the housing generally shown in FIG. 8.
In the upper region of the anti-return section (13), the water reservoir (12) is formed by an expansion which increases the volume in the antireturn section (13) which acts during the pumping out of the washwater as an ascending passage (15).
For the proper operation of the ball valve, it is important that the water reservoir (12) be located as high as possible inside the machine, and that the water column which forms in the passage (15) after the washwater pump is turned off remain as high as possible, so that the float (5) is pushed by the backflowing water with a strong force against the seal element (10) located in the washtub drain. For this reason, the water reservoir (12) should be located in the upper overflow area from duct (15) to duct (16).
FIG. 4 shows a float which consists of two hemispheres (51) and a filler (52) of foamed material. In relation to the material for the filler, care should be taken that it has a very low specific gravity, significantly less than one, and that its absorption capacity is also very low. The hemispheres (51) can thereby consist of a high-grade thermoplastic material, while the filler (52) can be made of a foamed plastic such as styropor or a similar material. The hemispheres (51) are joined together to include the filler (52), preferably by welding their contact surfaces. Here too, a mechanical snap connection would be conceivable, or a water-resistant adhesive connection in the area of the shell edges in contact with one another.
In the embodiment illustrated in FIG. 5, the filler (52) is formed by the injection of a two-component foam (53) before the shells (51) are joined together. During or after the connection of the two hemispheric shells (51) with one another, a chemical-thermal reaction takes place inside the closed float, by means of which the two-component foam (53) expands and thus fills up the inside of the float.
If a two-component foam (53) is available which is not hygroscopic, it can also be subsequently injected into the hollow float.
In the embodiment illustrated in FIG. 6, first the filler (52) is fabricated from a foamed plastic, and then the coating (54) is formed by immersion, sintering, spraying or a similar method. Finally, for the fabrication of a suitable float, a multicomponent injection molding process of the prior art can also be used. In this case, an economical plastic is used internally as the filler (52), and is then provided with an external coating (54) of a higher-grade thermoplastic material.
The fundamental principle of the invention is explained in greater detail below, with reference to the accompanying FIG. 2: At the end of the washing cycle, the washwater pump (3) is turned off, and the remaining water flowing back from the drain tube (4) and from its water reservoir (12) reaches the washtub drain (2). The float (5) is thereby pushed upward with sufficient bouyancy and presses against the seal housing of the seal element (10). On account of the relatively soft sealing lip of the seal element (10), a secure seal of the float (5) inside the drain opening is achieved. During the subsequent washing cycle, the detergent dispensed can no longer get into the drain system of the machine and be pumped out unused.
After the machine has not been operated for a rather long period of time, it may be that in the period between two wash cycles, unavoidable small leaks can allow water to penetrate from the drain system into the washtub. Then the buoyancy of the float could be weakened, and the closing action in the washwater tank drain would not occur. A remedy can consist of taking precautions in the control equipment of the washing machine, so that the washwater pump (33) of the machine is turned on for a short time, e.g. for 2-6 seconds, at the beginning of each new wash cycle. The remaining water in the machine is thereby pushed into the drain tube (4) and during the backflow, the float (5) is again pressed into the sealing seat.
The operation of the apparatus illustrated in FIG. 1 is described below: The sequence of the machine wash cycle is controlled by the program control apparatus (19). The detergent required for the washing process is added in a known manner via the detergent dispenser (23) and the connection hose (24) to the tub (1). A solenoid valve (25) or a group of solenoid valves is located in the water feed line, and controls the addition of fresh water to the machine in the conventional manner.
As a rule, the washing liquid is pumped out at the end of a wash cycle. The washwater pump (3) turned on by the programm control apparatus (19) drains the washwater from the machine via the passage (15). If the washwater pump (3) is turned off, then the remaining water flows out of the water reservoir (12) and the passage (15) through the washwater pump back into the chamber (21) of the tub drain (2) and pushes the float (5) into the seal element (10). The tub drain is thereby closed, and during the subsequent wash cycle, no detergent can escape unused into the drain system. In this case, the following control measures can be adopted to replace or increase the water column in the passageway (15).
Before a program segment which involves the addition of detergents, e.g. the pre-wash or the main wash, the solenoid valve (25) of the program control apparatus (19) is turned on for a short time and fresh water is transported into the tub (1) via a bypass (not shown in any further detail) or a dispensing chamber of the detergent dispenser (23) containing no detergent. After a delay period, which guarantees the arrival of this water in the bottom of the tub (1), the program control apparatus (19) turns on the washwater pump (3) for a short time, so that the water is pulled out of the tub (1) into the drain system. The quantity of fresh water admitted and the time the solenoid valve (25) and the washwater pump (3) are turned on is selected so that the water column in the passage (15) can form up to the upper edge of the water reservoir (12). It may suffice for the solenoid valve (25) to be turned on for at least 3 seconds, and after at least 10 seconds from the time the solenoid valve (25) is turned on, to turn on the washwater pump (3) for 1 second.
In another embodiment, while the wash cycle is in progress, the solenoid valve (25) can be turned on for a short time at the end of a program segment, e.g. at the end of the pre-wash. The brief pumping-out by turning on the washwater pump (3) can then occur at the beginning of the subsequent program segment, the main wash.
Another advantageous measure can consist of turning on the solenoid valve (25) and the washwater pump (3) in the manner described above after the end of the washing process itself, after the spin.
Another advantageous precaution can be taken at the end of the wash program, of the "spin" segment, by keeping the washwater pump (3) in a status where it can be turned on until the washtub actually comes to a stop, and not turning it off as usual with the spin motor. That prevents any leaks caused by vibrations during the runout of the drum caused by movements of the float (5) in the seal apparatus.
It can also occur, however, that the washwater pump (3) is turned on for a short period at an undesirable point. If the user has started a wash cycle in which the detergent has already been dispensed, and if, for example, he restarts the machine for a modified cycle, then all of the detergent would be sucked into the drain sump, without being used for a washing process. Here, a means is created whereby the program control apparatus (19) of the machine prevents the short-term operation of the washwater pump (3) if, as described above, the detergent has already been dispensed. In the practical embodiment, the program control apparatus (19) can thereby contain a memory, e.g. an NVRAM, which stores the most recent program status and continues the program, omitting the activation of the washwater pump (3) and of the solenoid valve (25). This effectively prevents an unintentional discharge of detergents.
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A washing machine which includes a wash tub for receiving water and articles to be washed, a drain connected to the wash tub, a float disposed within the drain, a drain water reservoir for receiving and storing water removed from the wash tub through the drain and for providing back pressure on the float, and a pump for pumping water from the wash tub, through the drain, and into the drain water reservoir.
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RELATED APPLICATION
This application claims priory to U.S. provisional application 60/368,293 filed on Mar. 28, 2002, which is incorporated by reference in its entirety.
FIELD OF INVENTION
This invention relates to the sport of snowboarding and to an arrangement for supporting the weight of a snowboard while riding up a chairlift.
BACKGROUND OF INVENTION
Snowboarding is a rather new sport that began in the United States in the 1960s. Back then a short-thin board with a rope attached at the nose, called the “Snurfer”, was ridden without bindings. In the 1970s the current snowboard shape began to evolve, but it wasn't until the early 1980's that steel edges and P-tex bases popular with skis were introduced into snowboard technology.
This steel edge technology gave the control necessary in all snow conditions and the growth of the sport has mushroomed ever since. As is generally understood snowboarding is one of the rapidly growing sports today, with its enjoyment currently in excess of skiers for young people entering winter sports. In the early days of snowboarding many ski areas did not permit snowboarding on their slopes. Today, due in part to the improved image of snowboarding brought about by organized competition and the growing popularity of the sport itself only a few areas discriminate against snowboarders. The popularity and acceptance of snowboarding has spread worldwide. Snowboarding was recently recognized by the International Olympic Committee as a full medal sport for the 1998 Olympic Games in Japan.
While the popularity of snowboarding has seen explosive growth among young people its popularity has also been embraced by older people as an alternative to skiing. As the sport has evolved a series of improvements in equipment has occurred. It has been found desirable to fasten the snowboarder rider into place with a variety of specialized bindings. These bindings have taken the shape of several forms, however, common among all is the need to have the forward foot of a rider secured at all times.
Snowboard riders traditionally remove one of their boots from its binding for the ride up the chairlift. The free boot allows the rider to maneuver through the chairlift lines and onto the chairlift itself. The snowboard rider can either support the snowboard with the free foot or just let the snowboard hang by the foot secured in the front mounting. In the case where the snowboard is supported by the free foot this method of support often results in stress fatigue and discomfort to the leg supporting the board. In the case where the snowboard is hanging freely, the weight of the board has the tendency to cause injury to the ligaments, tendons and muscles of the foot bound in the binding. The weight of the snowboard itself has a tendency to pull on the ligaments, tendons, muscles, etc., causing damage over time that is exacerbated with the natural fatigue to the rider's leg that has tired through hours of activity.
Even with newer snowboards that have taken advantage of progress in material science to produce lighter weight snowboards made of fiberglass or similar resins, this undesirable stress upon the fixed foot's tendons, ligaments and muscles has not been alleviated. Unfortunately, during the course of a day, this stress, fatigue and discomfort reduces enjoyment of the sport and most importantly increases the chance of serious injury to the snowboard rider.
Prior solutions have produced a variety of leashing and strapping arrangements that consist of various methods to alleviate this fatigue to the snowboarder. U.S. Pat. No. 6,349,968 to Crego et al. (“Crego”) is a temporary hold-up device for a snowboard support. Crego discloses a temporary hold-up device for snowboard support that uses a substantially stiff cord to temporary support the board during the chairlift ride. The rider engages the unfastened binding mechanism with this substantially stiff cord to help support the weight of the snowboard during the chairlift ride. Unfortunately, this device is cumbersome and storage of the device between its use is problematic.
Another attempt to solve the problem of leg strain due to unsupported snowboard weight can be found in U.S. Pat. No. 6,290,260 to Brill (“Brill”). Brill provides a detachable loop strap which encircles a portion of the snowboard and goes over the rider's knee. The detachable loop of Brill appears to be a cumbersome and difficult device to use. Unfortunately, Brill much like Crego suffers from difficulty in use and storage of the device between use.
Accordingly, there is need for a device that will serve to support the snowboard in a way to prevent fatigue when the snowboarder is riding a chair lift or the like. There is further need for a support device that is compact and contains a convenient method for storage between its use.
SUMMARY OF INVENTION
Accordingly, it is an object of the present invention to provide a support mechanism for snowboard support while riding a chair lift. This support mechanism includes a retractable flexible cable contained within a housing having a recoil mechanism. The housing containing the retractable flexible cable is advantageously mounted to the snowboard or the binding mechanism of the snowboard assembly. The housing member having the retractable flexible cable has a coil spring assembly that retracts the flexible cable advantageously into the housing member. The housing member is strategically mounded to the snowboard or to the binding mechanism.
As the snowboard rider desires additional support for the weight of the snowboard, the free end of the retractable flexible cable is pulled to remove the cable from the housing member. The free end of the retractable cable is fitted with a handle having a configuration allowing the snowboard rider the ability to grasp the cable in their hand or to latch the retractable cable onto the chairlift's safety bar.
In an alternative illustrative embodiment, the handle may also be fitted with a locking member allowing the snowboard owner to secure their untended snowboard thereby preventing theft. The locking member within the handle configuration may be released by use of a combination lock or key. The housing member may further contain a retraction button on the housing member that causes the retractable flexible cable to rewind within the housing or it can be used to adjust the elongation length of the flexible cable.
The retractable flexible cable according to the invention can be adjusted to a desirable length for the comfort of various sizes of snowboard riders. Similarly, for securing the snowboard during periods of rest, the free end of the cable may be inserted around a stationary object, prior to insertion of the locking member into the receptor member contained within the housing member.
In yet a further alternative illustrative embodiment the handle on the free end of the retractable flexible cable can be further configured to accommodate tools, such as screwdriver heads, nut drivers or the like enabling the snowboarder the ability to adjust their equipment.
According to the invention, the housing member can be attached to the snowboard through the use of fasteners or adhesives. Similarly, the housing member can be attached to the binding mechanism through the use of fasteners.
In a further alternative illustrative embodiment the retractable flexible cable can be a pre-selected length so that adjustments to the cable length by the use of a retractable button are not necessary.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description of illustrative embodiments, taken in conjunction with the accompanying drawing in which:
FIG. 1 illustrates a traditional method of riding a chairlift with a snowboard having a back leg released from a binding mechanism;
FIG. 2 illustrates the method according to the invention of riding a chairlift with a snowboard while using the inventive support mechanism;
FIG. 3 illustrates the apparatus according to the invention having a housing with a retractable flexible cable;
FIG. 4 is a top cross sectional view of the housing containing the retractable flexible cable according to the invention; and
FIG. 5 is a bottom cross sectional view of the housing containing the retractable flexible cable according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Detailed embodiments of the present invention are disclosed herein, however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
As shown in FIG. 1 , typically a snowboarder 101 rides a chairlift 103 having a forward leg 105 securely strapped into a forward binding mechanism 107 . The forward binding mechanism 107 is secured to a snowboard 109 as is a back binding mechanism 111 . The back foot 106 of the snowboarder 101 is released from the back binding mechanism 111 prior to chairlift loading in order to allow the snowboarder 101 the ability to traverse and maneuver onto the chairlift 103 . As the snowboarder 101 rides the chairlift 103 the weight of the snowboard is supported solely by the forward leg 105 . This support over time causes the forward leg 105 to become fatigued.
According to the invention, as shown in FIG. 2 , a housing 201 having a retractable flexible cable 203 is mounted upon a snowboard 205 . The retractable flexible cable 203 has a free end 207 and a retracted end 209 . The free end 207 is equipped with a handle 211 . It is contemplated within the scope of the invention that the handle 211 may be configured to allow a snowboarder 213 the option of attaching the handle 211 to a safety bar 214 on a chairlift 210 . The handle 211 is held by a snowboarder 213 to assist in the support of the snowboard 205 . The snowboarder 213 having their forward leg 206 fastened into a front binding mechanism 208 and their back leg 204 unfastened from a back binding mechanism 216 is able to support the weight of the snowboard 205 by grasping the handle 211 .
The housing 201 contains a coil spring driven recoil mechanism that recoils the retractable flexible cable 203 when the snowboarder 213 releases the handle 211 . It is contemplated within the scope of the invention that the housing 201 may be attached to the snowboard 205 using fasteners or adhesives known in the art.
The housing is advantageously attached within the vicinity of the back binding mechanism 216 . It is further contemplated within the scope of the invention that the housing 201 may be attached to the back binding mechanism 216 . The attachment of the housing 201 can be of a permanent nature or it can be removably attached to either the snowboard 205 or the back binding mechanism 216 .
In operation of the inventive apparatus, when the snowboarder 213 sits on the chairlift 210 , he or she simply grasps the handle 211 of the retractable flexible cable 203 and adjusts the length to their comfort by the use of a release button contained within the housing 201 or by having a retractable flexible cable 203 having a pre-selected elongation length that is sized to the snowboarder's comfort.
Turning to FIG. 3 a housing 301 having a retractable flexible cable 303 according to the invention is shown. The housing 301 in a first illustrative embodiment is constructed of injected molded plastic. It is contemplated within the scope of the invention that the housing 303 may also be constructed of materials known in the art, such as metal alloys or the like. The flexible retractable cable 303 in a first illustrative embodiment is fabricated from a flexible steel cable that has been covered with a drag resistant plastic coating. It is contemplated within the scope of the invention that other materials known in the art may be used, such as nylon rope, fibrous woven rope, mountaineering rope or the like.
The retractable flexible cable 303 has a free end 305 and a retractable end 307 . The free end 305 of the retractable flexible cable 303 is fitted with a tee shaped handle 309 . The tee shaped handle 309 in a first illustrative embodiment is fabricated from soft rubber and is configured to allow a snowboarder to firmly grasp the tee shaped handle 309 . It is contemplated within the scope of the invention that the tee shaped handle 309 may be fabricated from a variety of plastics and metal alloys. It is further contemplated that the tee shaped handle 309 may be of other geometric forms such as u-shaped or the like.
As shown in FIG. 3 the tee shaped handle 309 has a first end 311 and a second end 313 . The first end 311 is configured to allow it to act as male portion of a locking mechanism. The housing 301 is further equipped with a housing locking mechanism 315 . The housing locking mechanism 315 is configured to allow the first end 311 of the handle 309 to be securely inserted into the housing locking mechanism 315 . The securely inserted first end 311 of the handle 309 allows the snowboarder to secure and lock his or her snowboard while not in use to prevent theft. The housing locking mechanism 315 may be equipped with either a combination or a key lock to securing the first end 311 into the housing member 301 .
In an alternative illustrative embodiment the second end 313 of the handle 309 is configured in the form of a hook allowing the snowboarder the ability to hook the handle 311 to a safety bar on the chairlift. The hook can be a quick release snap-type hook as used in mountaineering or can be merely a right angle hook for attachment to the safety bar.
In a further illustrative embodiment one or both ends 311 , 313 of the handle 309 of the retractable flexible cable 303 can be further configured to accommodate tools, such as screwdrivers head, nut drivers, or the like enabling snowboard riders the ability to adjust their equipment.
In yet a further illustrative embodiment the handle 311 is equipped with a plastic mesh strap having a break-a-way Velcro® fastening system allowing the snowboarder the ability to secure the retractable flexible cable 303 to a portion of the chairlift assembly.
As depicted in FIG. 3 the housing 301 has a top end 317 and a bottom end 319 . The top end 319 has an opening 321 allowing for the retractable flexible cable 303 to be released or retracted in and out of the housing 301 . The opening is fitted with a tapered grommet 323 that allows the retractable flexible cable 303 drag resistant movement in and out of the housing 301 . The tapered grommet 323 may be fabricated from nylon or other plastics that allow for a reduced drag coefficient upon the retractable flexible cable 303 . The tapered grommet 323 receives a tapered portion 330 of the handle 311 allowing the handle 311 in the retracted position to seal the housing 311 from moisture.
The bottom end 319 of the housing is configured to allow the housing 311 to be securely or removeably fastened to the snowboard. The housing 301 also has a proximal side 325 and a distal side 327 . Either the proximal side 325 or the distal side 327 can be configured to receive fasteners allowing the housing 301 to be securely or removable fastened to a binding mechanism. The bottom end 319 of the housing 311 is further equipped with drain holes 331 allowing moisture to drain from the housing 301 .
The top end 317 of the housing 301 is further equipped with a release mechanism 329 . The release mechanism 329 is engaged with the recoil mechanism allowing adjustment to the elongation length of the retractable flexible cable 303 . It is contemplated within the scope of the invention that the elongation length of the retractable flexible cable 303 can be adjusted by the use of the release mechanism 329 . It is further contemplated that the retractable flexible cable 303 can have a pre-selected length.
Turing to FIG. 4 a top cross sectional view of a housing 401 according to the invention is shown. The housing 401 contains a release mechanism 403 allowing for adjustment to the elongation length of a retractable flexible cable 409 . The release mechanism 403 engages or disengages a ratchet assembly 405 by the use of a spring 407 engaged ratchet stop 409 . The ratchet assembly 405 is attached to a coil spring recoil mechanism (not shown) that recoils the retractable flexible cable 409 . It is contemplated within the scope of the invention that other means for adjustment of the retractable flexible cable 409 known in the art may be used, such as friction engagement or the like.
Turning to FIG. 5 a bottom cross sectional view of the housing 501 according to the invention is shown. The retractable end 503 of a retractable flexible cable 505 is attached to a coil spring 507 . The coil spring 507 is fastened to a ratchet assembly 509 . The coil spring 507 is configured from spring steel as known in the art. The ratchet assembly 509 is engaged by a spring 512 assisted release mechanism 511 allowing for adjustment to the elongation length of the retractable flexible cable 505 as described above.
Although the illustrative embodiment uses a ratchet assembly to adjust the elongation length of the retractable flexible cable, it should be appreciated by those skilled in the art that methods such as fiction engagement or the like may be used as a means for adjustment.
Although the illustrative embodiment is attached to the snowboard or binding mechanism, it should be appreciated by those skilled in the art that the retractable flexible cable apparatus can be incorporated into the structure of snowboard binding mechanisms.
Although the illustrative embodiment is used for a support mechanism or locking mechanism, it should be appreciated by those skilled in the art that the retractable flexible cable can be used as a safety leash for the snowboard.
The foregoing has been a description of certain specific embodiments of the present disclosure. The present disclosure is not to be limited in scope by the illustrative embodiments described which are intended as specific illustrations of individual aspects of the disclosure, and functionally equivalent methods and components are within the scope of the invention. Indeed, various modifications of the disclosure, in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description and all such modifications are included.
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A mechanism for snowboard support while riding a chair lift is provided. The support mechanism includes a flexible retractable cable within a housing having a recoil mechanism. The housing is advantageously mounted to the snowboard or the snowboard binding mechanism. The recoil assembly has two main elements, a housing member which stores a retractable cable and a spring assembly that retracts the flexible cable advantageously into the housing member. The recoil assembly may allow for adjustment of an elongation length of the retractable flexible cable.
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a utility application claiming priority to U.S. Provisional Application Ser. No. 61/212,104 filed Apr. 7, 2009, and incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to body-implantable devices. More particularly, the present invention relates to a percutaneously insertable and expandable inter-vertebral disc prosthesis. Specifically, the present invention comprises a novel nuclear prosthesis, a specially designed delivery apparatus, and a loading apparatus for loading the nuclear prosthesis within the delivery apparatus.
2. Description of the Related Art
The role of the inter-vertebral disc in spine biomechanics has been the subject of extensive research and is generally well understood. A typical native spinal unit is shown for exemplary purposes in FIG. 22A . The functional spinal unit, or spinal motion segment 500 consists of two adjacent vertebrae 502 and 504 , the inter-vertebral disc 506 and the adjacent ligaments (not shown). The components of the disc are the nucleus pulposus 506 a , the annulus fibrosis 506 b , and the vertebral end-plates 506 c . These components act in synchrony and their integrity is crucial for optimal disc function. During axial loading of the normal native disc 506 , the pressure of the nucleus pulposus 506 a rises, transmitting vertical force on the end plates 506 c and outward radial stress on the annulus fibrosis 506 b , as shown by the direction arrows in FIG. 22A . The vertical stress is transformed to tensile forces in the fibers of the annulus fibrosis 506 b . Because the gelatinous nucleus pulposus 506 a is deformable but noncompressible, it flattens radially, and the annulus fibrosis 506 b bulges and stretches uniformly. Flexion of the spine involves the compression of the anterior annulus fibrosis 506 b , as well as the nucleus pulposus 506 a . The nucleus pulposus 506 a deforms and migrates, posteriorly stretching the annular fibers and expanding radially. Thus, the nucleus pulposus 506 a and annulus fibrosis 506 b function synergistically as a cushion by reorienting vertical forces radially in a centrifugal direction.
The native vertebral end plate 506 c prevents the nucleus pulposus from bulging into the adjacent vertebral body by absorbing considerable hydrostatic pressure that develops from mechanical loading of the spine. The end plate 506 c is a thin layer of hyaline fibrocartilage with subchondral bone plate, typically around 1 millimeter thick. The outer 30% of the end plate 506 c consists of dense cortical bone and is the strongest area of the end plate 506 c . The end plate 506 c is thinnest and weakest in the central region adjacent to the nucleus pulposus.
With aging and repetitive trauma, the components of the inter-vertebral disc 506 undergo biochemical and biomechanical changes and can no longer function effectively, resulting in a weakened inter-vertebral disc 506 . As the disc 506 desiccates and becomes less deformable, the physical and functional distinction between the nucleus pulposus 506 a and the annulus fibrosis 506 b becomes less apparent. Disc desiccation is associated with loss of disc space height and pressure. The annulus fibrosis 506 b loses its elasticity. The apparent strength of the vertebral end-plates 506 e decreases and vertebral bone density and strength are diminished. This leads the end-plates 506 c to bow into the vertebral body, imparting a biconcave configuration to the vertebral body. Uneven stresses are created on the end plates 506 c , annulus fibrosis 506 b , ligaments (not shown), and facet joints (not shown), leading to back pain. At this point, the annulus fibrosis 506 b assumes an inordinate burden of tensile loading and stress, and this further accelerates the process of degeneration of the annulus fibrosis 506 b . Fissuring of the annulus fibrosis 506 b further diminishes its elastic recoil, preventing the annulus fibrosis 506 b from functioning as a shock absorber. Leakage of the nuclear material can cause irritation of the nerve roots by both mechanical and biochemical means. Eventually, degenerative instability is created, leading to both spinal canal and neuroforaminal stenosis.
Historically, spine surgery consisted of simple decompressive procedures. The advent of spinal fusion and the proliferation of surgical instrumentation and implants has led to an exponential utilization of expensive new technologies. As an alternative to open surgical discectomy and fusion, Minimally Invasive Spinal Surgery (MISS) has been advocated. Thus far, the primary rationale for favoring the MISS approach has been to lessen postoperative pain, limit the collateral damage to the surrounding tissues, and hasten the recovery process rather than affect long term outcomes. Despite the lack of clear superiority and outcome data, these technologies have continued to flourish.
However, many spinal surgeons remain skeptical about the positive claims regarding MISS, citing certain drawbacks, including increase in operating room time, requirement for expensive proprietary instruments, increased cost, and the technically demanding nature of the procedure. Despite the advantage of a minimal incision approach, MISS requires an adequate decompression and/or fusion procedure in order to have results comparable to traditional open surgical approaches.
Ideally, a nuclectomy and implant insertion would be performed through a percutaneous posterolateral approach. Advantages of the percutaneous posterolateral approach over conventional open surgery and MISS include obviating the need for surgically exposing, excising, removing, or injuring interposed tissues; preservation of epidural fat; avoiding epidural scarring, blood loss, and nerve root trauma. Other advantages include minimizing “access surgery” and hospitalization costs, and accelerating recovery. A percutaneous procedure may be expeditiously used on an outpatient basis in selected patients. On the other hand, percutaneous insertion imposes a number of stringent requirements on the nuclear prosthesis and its method of delivery.
Several devices have been used to fill the inter-vertebral space void following discectomy in order to prevent disc space collapse. These devices generally fall into two categories: fusion prostheses and motion prostheses. Fusion prostheses intended for MISS insertion offer few if any advantages over those for open surgical technique. While these types of implants eliminate pathological motion, they also prevent normal biomechanical motion at the treated segment. Greater degrees of stress are transmitted above and below the treated segment, often leading to accelerated degeneration of adjacent discs, facet joints, and ligaments (adjacent level degeneration).
Motion prostheses generally aim at restoring disc height, shock absorption, and range of motion, thus alleviating pain. Artificial motion prostheses may be divided into two general types: the total disc prosthesis and the nucleus prosthesis. The total disc prosthesis is designed for surgical insertion, replacing the entire disc, while the nucleus prosthesis is designed for replacing only the nucleus pulposus, and generally may be inserted by open surgical or MISS methods.
Prior designs of motion nucleus prostheses include enclosures that are filled with a diverse variety of materials to restore and preserve disc space height while permitting natural motion. However, there are several shortcomings of prior nucleus motion prostheses designs. Some of the prior nucleus motion prostheses require surgical approaches for insertion that involve removal of a significant amount of structural spinal elements including the annulus fibrosis. Removal of these structural spinal elements causes destabilization of the spinal segment. Prior nuclear motion prosthesis designs also fail to provide the outer margin of the nuclear prosthesis with surface and structural properties that encourage native tissue ingrowth. Instead, such prostheses are made from generally non-porous materials that impede full incorporation of the nuclear prosthesis into the surrounding annular margin.
Some prior designs have annular bands along the outer periphery of the nucleus motion prostheses. However, prior annular bands are non-compliant. This is disadvantageous because it reduces the radial outer expansion required for load dampening. Thus, the load is transferred to the end plates of the vertebrae, which can withstand only limited deformation. The result is that the end plates eventually fail, resulting in loss of intradiscal pressure, accelerated degeneration, and subsidence of the nuclear prosthesis. Other prostheses do not have an annular band. These prostheses tend to exert untoward pressure on an already weakened annulus fibrosis. Particularly, such a prosthesis tends to protrude into a pre-existing annular tear.
Other designs fail to incorporate or use a central gas cushion with a valve system or assembly that does not leak. Still others concentrate the harder load bearing component of the nuclear prosthesis in the central aspect of the disc, predisposing the nuclear prosthesis to subsidence. Another problem with prior nuclear motion prostheses is the imprecise sizing and tailoring of the nuclear prosthesis. Over sizing places unnecessary stress on the already damages and degenerated annulus fibrosis, while under sizing of the nuclear prosthesis may result in inadequate contact with the inner wall of the annulus fibrosis, and possibly non-integration and migration of the nuclear prosthesis. Other designs of nucleus motion prostheses suffer draw backs such as bulkiness, inelasticity, inability to fold and pack the nuclear prosthesis into a delivery cannula or apparatus for percutaneous implantation into a patient. In fact, percutaneous delivery of a motion nucleus prosthesis heretofore, has been unavailable.
Applicants here propose to overcome the disadvantages of the prior designs of nucleus motion prostheses by providing a multi-compartment nuclear prosthesis having a semi-compliant annular reinforcement band disposed adjacent or contiguously around the periphery of a rubber filled annular enclosure. The annular enclosure nests a central, gas cushioned nuclear enclosure and an integrated sealing valve assembly. The nuclear prosthesis of the present invention is foldable to fit within a delivery apparatus, and is intended for percutaneous insertion into a nuclear space void following percutaneous total nuclectomy. Once percutaneously inserted, the nuclear prosthesis is expandable by an inflation-assisting device to provide cushioning and stability to a spinal segment weakened by degeneration.
SUMMARY OF THE INVENTION
The present invention overcomes the deficiencies of prior nuclear motion prostheses, offers several advantageous properties, and provides a system for sizing, forming, delivering, and deploying a nuclear prosthesis into the inter-vertebral disc space. The percutaneously implantable nuclear prosthesis, formed in accordance with the present invention, utilizes the advantages of both a textile prosthesis and a polymer prosthesis to create a compartmentalized composite structure, having characteristics closely resembling the properties of a healthy native inter-vertebral disc. The nuclear prosthesis is comprised of an annular structure and a nuclear structure. The annular structure comprises an annular enclosing layer which defines an annular enclosure, an annular reinforcement band adjacent the periphery of the annular enclosing layer, a sealing valve core disposed within the annular enclosure and adjacently attached to the annular enclosing layer, and in-situ curable rubber, which is injected into the annular enclosure. The nuclear structure comprises a nuclear enclosing layer which defines a nuclear enclosure and an indwelling catheter mounted and bonded to a neck portion of the nuclear enclosing layer, and extends distally into, and is enclosed within the nuclear enclosure.
Referring to FIG. 22B the structure of the nuclear prosthesis comprising the annular structure 11 filled with the deformable, but not compressible in-situ curable rubber and the nuclear structure 21 centrally located within the annular structure 11 and being filled with a compressible gas allows for the vertical and horizontal load stresses placed on the inter-vertebral disc space to be redirected inward, centrally toward the nuclear structure 21 (see direction arrows of FIG. 22B ), instead of outward. Moreover, annular structure 11 has a biocompatible outer annular reinforcement band that encourages tissue in-growth of the native annulus fibrosis 506 b , thereby providing reinforcement to the native annulus fibrosis.
According to the present invention, there is provided a percutaneously insertable and detachable nuclear prosthesis having an annular enclosing layer that defines an annular enclosure. The annular enclosing layer is made of an annular tubular elastomeric membrane, is contiguous along its outer periphery with a textile annular reinforcement band, and incorporates a sealing valve core. Central to the annular enclosing layer is a nuclear enclosing layer defining a nuclear enclosure. The nuclear enclosing layer has a neck region. The neck region of the nuclear enclosing layer defines an open mouth that receives an indwelling catheter. The neck region is mounted on the indwelling catheter. The indwelling catheter is a tube that defines a lumen. The indwelling catheter is coupled to a sealing valve core which is disposed within the annular enclosure, and has its lumen plugged by a sealing plug after inflation within the inter-vertebral disc space.
The nuclear prosthesis is detachably mounted to a distal end of an inflation stylus and is loaded within a distal end of a delivery apparatus. The inflation stylus has three inflation tubes projecting from the distal end of the inflation stylus and slidably insertable through the sealing valve core of the sealing valve assembly. The sealing valve core is formed of a resilient material and has three pathways being defined by three parallel channels extended through the sealing valve core. Upon insertion of the three inflation tubes of the inflation stylus through the channels of the sealing valve core, the pathways take the form of cylindrical apertures in precise mating alignment with the inflation tubes of the inflation stylus to provide fluid-tight seal against and around the outer surfaces of the inflation tubes. The central inflation tube is a nuclear access tube that provides pressurized fluid to the nuclear enclosure. One of the outer tubes is an annular inlet tube that provides pressurized fluid to the annular enclosure through an inlet port provided in the sealing valve core. The other outer tube is an annular outlet tube that receives pressurized fluid from the annular enclosure through an outlet port provided in the sealing valve core.
The annular inlet tube and the annular outlet tube have side pores in the walls of the tubes adjacent the closed tips of the tubes whereby in-situ vulcanizing rubber flows through the side pore in the annular inlet tube into one end of the annular enclosure and back through the side pore of the annular outlet tube, and into the inflation stylus. After inflation of the annular enclosure and nuclear enclosure, the inflation stylus can be efficiently disengaged from the sealing valve core, and upon withdrawal thereof, the pathways return to an elongated slit or channel configuration to provide a fluid tight seal for the inflated nuclear prosthesis.
It is, therefore, a general object of the present invention to provide a nuclear prosthesis which exhibits an optimal overall combination of physical, viscoelastic, and other properties superior to previous designs of motion nucleus prostheses.
It is another object of the present invention to provide a nuclear prosthesis that is fundamentally reliable and durable, and utilizes the latest in surface modification technology to enhance the bio-compatibility, bio-durability, infection resistance, and other aspects of performance.
It is another object of the present invention to provide a nuclear prosthesis that reduces stress on the vulnerable central portions of the native vertebral end plates.
It is another object of the present invention to reduce the stress on the vulnerable central portions of the native vertebral end plates by providing a nuclear prosthesis that redirects the vector of forces caused by load stress inward, toward the core or center of the nuclear prosthesis. In this regard, the present invention provides a gas-filled central enclosure to aide in load bearing, cushioning, shock absorption and stabilization by directing the vector of forces toward the gas-filled central enclosure. The present invention redirects both lateral and vertical forces toward the gas-filled central enclosure, thereby providing protection to the vertebral end plates. The present invention accomplishes the redirection of vector forces by having a non-compliant annular reinforcement band along the outer periphery of the nuclear prosthesis, and a compressible gas filled central nuclear enclosure.
It is yet another object of the present invention to provide a nuclear prosthesis that provides reinforcement and structural support to the native annulus fibrosis. The annular reinforcement band of the present invention encourages native tissue in-growth of the native annulus fibrosis to provide added stabilization and reinforcement.
It is still another object of the present invention to provide a nuclear prosthesis wherein the compliance of the nuclear prosthesis increases progressively toward the center of the nuclear prosthesis. Each component of the nuclear prosthesis is tailored to provide suitable viscoelastic properties that contribute to the overall performance of the nuclear prosthesis. This arrangement is intended to relieve the stress on the native annulus fibrosis by redirecting the radial outer vector of forces centrally toward the nuclear enclosure. The nuclear prosthesis is thus rendered iso-elastic with respect to the spinal segment.
Yet another object of the present invention is to provide a nuclear prosthesis that has expansion tailorability. The nuclear prosthesis can be expanded to variable sizes to accommodate the dimensions of the evacuated nuclear space. The nuclear enclosing layer, annular enclosing layer and annular reinforcement band possess the ability to be first inflated or stretched to its unextended or working profile and then, there-beyond to a limited extent and/or controlled extent by the application of greater pressure. The controlled flexibility of the textile annular reinforcement band and the expansion of the annular and nuclear enclosures can accommodate a wider range of nuclear space dimensions, reducing the need to precisely match the nuclear prosthesis to the nuclear space as to size.
It is yet a further object of the present invention to provide an inflation-assisted expandable nuclear prosthesis that distracts the disc space, and supports and reinforces the annulus fibrosis while keeping the ligaments and facet joints in a taut condition.
It is another object of the present invention to provide a novel sealing valve assembly which has a sealing valve core integrally bonded to the annular enclosing layer within the annular enclosure, having a mounting region adapted on its inner margin for fluid tight bonding to an indwelling catheter lying within the nuclear enclosure. The sealing valve core of the sealing valve assembly is detachably connected to the tip of the delivery apparatus and is self-sealing upon removal of the inflation stylus.
It is another object of the present invention to provide a nuclear prosthesis which can be geometrically and elastically deformed to reduce its axial and transverse diameter through radial elongation, into a minimal profile for ease of insertion into the delivery apparatus, while minimizing the risks that could be associated with such flexibility. This is achieved by the components of the nuclear prosthesis being suitably configured and dimensioned to form a perfect mating fit to each other and to the nuclear enclosing layer. The annular reinforcement layer, annular enclosing layer and nuclear enclosing layer must cooperate in a synchronized fashion to achieve a precise folded and wrapped configuration. The folding of the nuclear prosthesis is further achieved by minimizing the combined thicknesses of the annular enclosing layer and nuclear enclosing layer and optimizing the longitudinal flexibility and radial compliance of the annular reinforcement band by careful selection of the type of bio-compatible yarn, the number of layers, the heat set conditions, and the angles at which braids are formed. The folding of the nuclear prosthesis is also aided by the selection and use of a semi-compliant medical balloon material for the annular and nuclear enclosing layers.
It is further an object of the present invention to provide a nuclear prosthesis that has a porous outer margin thereby facilitating the incorporation of the nuclear prosthesis into the nuclear space.
It is yet another object of the present invention to provide a delivery apparatus having an assembly of coaxial telescoping cannulas with the nuclear prosthesis disposed therein, and a method of delivering the nuclear prosthesis percutaneously to the nuclear space. The delivery apparatus houses and carries the folded nuclear prosthesis within its delivery cannula. The delivery cannula also houses and incorporates an inflation stylus defining three tubes in fluid communication with the three chambers or pathways of the sealing valve core of the nuclear prosthesis. Within the delivery cannula is a specially designed release cannula adjacent the sealing valve core to release the inflation stylus from the nuclear prosthesis.
A typical procedure for implantation of the nuclear prosthesis involves performing an initial percutaneous nuclectomy through a percutaneous access device, insertion of the delivery apparatus within the percutaneous access device, insertion of the delivery cannula carrying the nuclear prosthesis and deploying the nuclear prosthesis within the nuclear space void. In deployment, the annular and nuclear enclosures are expanded using any suitable fluid delivery system, allowing the nuclear prosthesis to assume a substantially discoid shape as the nuclear prosthesis radially and axially expands and substantially conforms to the shape of the nuclear space void.
The annular and nuclear enclosures are inflated simultaneously with a pressurized liquid until adequate disc space distraction is achieved and a predetermined pressure level within the nuclear prosthesis is achieved. The annular enclosure is inflated with an in-situ curable rubber, and the nuclear enclosure is inflated with a liquid such as saline. After curing of the in-situ curable rubber within the annular enclosure occurs, the liquid within the nuclear enclosure is replaced with a compressible gas. Nitrogen, carbon dioxide, or many other suitable gases can be used within the nuclear enclosure. At this point, the indwelling catheter is plugged with a sealing plug introduced into the indwelling catheter and pushed therein. The delivery cannula is detached from the sealing valve core by the release cannula, and the delivery apparatus is then removed.
These and other objects, aspects, features and advantages of the present invention will be clearly understood and explained with reference to the accompanying drawings and through consideration of the following detailed description.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional side view of the annular structure of the nuclear prosthesis of the present invention;
FIG. 1A is a sectional side view of the loading apparatus of the present invention with an inflated nuclear prosthesis of the present invention therein;
FIG. 1B is a sectional side view of an inflated annular enclosing layer of the nuclear prosthesis of the present invention;
FIG. 1C is a sectional side view of an inflated annular enclosing layer of the nuclear prosthesis of the present invention;
FIG. 1D is a sectional top view of the delivery apparatus of the present invention with the nuclear prosthesis of the present invention loaded therein;
FIG. 2 is a sectional side view of an inflated annular enclosing layer and deflated nuclear enclosing layer of the nuclear prosthesis of the present invention;
FIG. 2A is a sectional side view of the loading apparatus of the present invention with a partially deflated nuclear prosthesis of the present invention therein;
FIG. 2B is a sectional side view of the annular enclosing layer of the nuclear prosthesis of the present invention in a partially stretched position during loading into the delivery apparatus;
FIG. 2C is a sectional side view of the nuclear prosthesis of the present invention in a partially deflated state;
FIG. 2D is a sectional top view of the delivery apparatus of the present invention with the nuclear prosthesis of the present invention loaded thereon;
FIG. 3 is a sectional side view of the nuclear prosthesis and the inflation stylus of the present invention;
FIG. 3A is a sectional side view of the loading apparatus of the present invention showing the loading of a deflated nuclear prosthesis of the present invention onto the delivery apparatus of the present invention;
FIG. 3B is a sectional side view of the annular enclosing layer of the nuclear prosthesis of the present invention in a fully stretched position during loading onto the delivery apparatus;
FIG. 3C is a sectional side view of the nuclear prosthesis showing the folding of the annular enclosing layer around the nuclear enclosing layer when the nuclear prosthesis is deflated;
FIG. 3D is a sectional top view of the delivery apparatus of the present invention with the nuclear prosthesis of the present invention loaded thereon and retracted therein, with the delivery apparatus disposed within an access cannula;
FIG. 4 is a sectional top view of the nuclear prosthesis and the inflation stylus of the present invention;
FIG. 5 is a sectional top partially exploded view of the sealing valve core of the sealing valve assembly of the nuclear prosthesis of the present invention;
FIG. 6 is a sectional top view of the sealing valve core of the sealing valve assembly of the nuclear prosthesis of the present invention;
FIG. 7 is a sectional top view of the sealing valve core of the sealing valve assembly of the nuclear prosthesis of the present invention;
FIG. 8 is a side view of the indwelling catheter and the mounting region of the nuclear enclosing layer of the nuclear prosthesis of the present invention;
FIG. 9 is a sectional side view of the annular enclosing layer, retaining ring and the layers of the annular reinforcement band of the nuclear prosthesis of the present invention;
FIG. 10 is a sectional side view of the inflation stylus of the present invention and the of the nuclear prosthesis of the present invention showing interaction of the nuclear access tube with the indwelling catheter;
FIG. 11 is a sectional top view of the inflation stylus of the present invention;
FIG. 11A is a sectional top view of the inflation stylus of the present invention and the of the nuclear prosthesis of the present invention showing interaction of the tubes of the inflation stylus with the ports and pathways of the sealing valve core;
FIG. 11B is a sectional top view of the inflation stylus of the present invention and the of the nuclear prosthesis of the present invention showing interaction of the tubes of the inflation stylus with the ports and pathways of the sealing valve core;
FIG. 12 is a side view of the release cannula of the delivery apparatus of the present invention interacting with the annular enclosing layer of the nuclear prosthesis of the present invention;
FIG. 13 is a side view along line 12 - 12 of FIG. 12 showing the connection of the inflation stylus to the of the nuclear prosthesis of the present invention;
FIG. 14 is a sectional side view showing the connection of the inflation stylus to the of the nuclear prosthesis of the present invention;
FIG. 15 is a sectional side view showing the connection of the inflation stylus to the of the nuclear prosthesis of the present invention;
FIG. 16 is a sectional side view showing the annular enclosing layer folded around the nuclear enclosing layer when the is a sectional side view showing the connection of the inflation stylus to the of the nuclear prosthesis of the present invention is deflated;
FIG. 17 is a perspective view of the outer layer of the annular reinforcement band of the nuclear prosthesis of the present invention;
FIG. 18 is a perspective view of one of the middle layers of the annular reinforcement band of the nuclear prosthesis of the present invention;
FIG. 19 is a perspective view of the inner layer of the annular reinforcement band of the nuclear prosthesis of the present invention;
FIG. 20 is a sectional side view of the nuclear prosthesis of the present invention after delivery and inflation with fluid within the patient;
FIG. 21 is a sectional side view of the nuclear prosthesis of the present invention after delivery and inflation with fluid within the patient;
FIG. 22A is a rear view of a native inter-vertebral disc space showing the direction of dispersion of typical horizontal and vertical load forces; and
FIG. 22B is a rear view of an inter-vertebral disc space with the nuclear prosthesis of the present invention therein, showing redirection of dispersion of typical horizontal and vertical load forces by the nuclear prosthesis of the present invention.
DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 through 4 the nuclear prosthesis 10 of the present invention is disclosed. Nuclear prosthesis 10 comprises an annular structure 11 and a nuclear structure 21 . Annular structure 11 comprises an annular enclosing layer 12 defining an annular enclosure 14 , and nuclear structure 21 comprises a nuclear enclosing layer 22 defining a nuclear enclosure 24 . Nuclear enclosing layer 22 is disposed adjacent annular enclosing layer 12 in the central space defined by annular enclosing layer 12 , along an inner margin 16 thereof. Annular structure 11 of nuclear prosthesis 10 further comprises an annular reinforcement band 20 contiguous with or adjacent a peripheral or outer margin 18 of the inflatable annular enclosing layer 12 and a sealing valve core 28 of a sealing valve assembly 26 . Annular enclosing layer 12 incorporates the sealing valve core 28 and annular enclosure 14 filled in-situ with curable rubber. In its inflated state, nuclear prosthesis 10 is substantially discoid in shape, as shown in FIGS. 20 and 21 .
Annular enclosure 14 is in communication with an inlet port 36 a and an outlet port 38 a of sealing valve core 28 . Nuclear structure 21 comprises nuclear enclosing layer 22 , which defines a discoid inflatable nuclear enclosure 24 , and an indwelling catheter 32 . A neck portion 22 a of nuclear enclosing layer 22 is mounted on indwelling catheter 32 , which has a side-pore 32 a and a closed tip 32 d (see FIG. 8 ). Nuclear enclosing layer 22 is filled in-situ with compressible gas and converges on a neck portion 22 a adapted for fluid-tight bonding to indwelling catheter 32 (see FIG. 8 ). Returning to FIGS. 1 through 4 , indwelling catheter 32 includes a bulbous portion 32 b on the proximal end thereof, which is adapted to be coupled within a sealing valve core 28 of sealing valve assembly 26 to a pressurized fluid for inflation of nuclear enclosure 24 . Bulbous portion 32 b of indwelling catheter 32 is snap-secured and adhesively bonded to sealing valve core 28 so that a fluid-tight connection will be achieved.
Referring to FIGS. 1D , 2 D and 3 D, a delivery apparatus 200 is disclosed. Delivery apparatus 200 is coaxially and telescopically slidable within an access cannula 202 . A distal delivery cannula 204 of delivery apparatus 200 coaxially encloses a release cannula 206 (see FIGS. 10 , 11 A, 11 B and 12 ) and an inflation stylus 100 . Referring to FIGS. 4 , 11 , 11 A and 11 B, inflation stylus 100 is a rigid tube with a triple lumen that terminates in three inflation tubes 102 , 104 and 106 . Inflation tubes 102 , 104 and 106 define inflation lumens therein, and are in fluid communication with annular enclosure 14 and nuclear enclosure 24 via sealing valve core 28 . The three inflation tubes are an annular inlet tube 102 , an annular outlet tube 104 and a nuclear access tube 106 . Annular inlet tube 102 , annular outlet tube 104 and nuclear access tube 106 project from the distal end of inflation stylus 100 and are detachably secured to three corresponding pathways 36 b , 38 b and 40 , respectively, within sealing valve core 28 .
Inflation tubes 102 , 104 and 106 are adapted to mate with the three corresponding pathways 36 b , 38 b and 40 , respectively, of sealing valve core 28 . In order to couple inflation stylus 100 to sealing valve core 28 , inflation tubes 102 , 104 and 106 are inserted through the inflation bores 36 c , 38 c and 40 a , respectively, which are disposed on the outer margin of sealing valve core 28 (see FIGS. 12 through 14 ). Inflation tubes 102 , 104 and 106 then extend into the slit-like pathways 36 b , 38 b and 40 , respectively.
A fluid-tight communication is formed between annular enclosure 14 through inlet port 36 a and outlet port 38 a , and through annular inlet tube 102 and annular outlet tube 104 . Annular inlet tube 102 has a side pore 102 a , and annular outlet tube 104 has a side pore 104 a . Side pores 102 a and 104 a are located towards the closed distal ends of the annular inlet tube 102 and annular outlet tube 104 , respectively. Side pore 102 a provides a fluid-tight communication with inlet port 36 a , and side pore 104 a provides a fluid-tight communication with outlet port 38 a of sealing valve core 28 . A third fluid-tight communication is formed between nuclear enclosure 24 and inflation stylus 100 , through nuclear access tube 106 , which terminates with an end bore 106 a . Nuclear access tube 106 slides through passage 40 a and engages a proximal end 32 c of indwelling catheter 32 .
Referring to FIGS. 4 through 9 , 11 A and 11 B, the design of sealing valve assembly 26 is disclosed. Sealing valve assembly 26 employs sealing valve core 28 which permits the passage of fluid through inlet port 36 a , outlet port 38 a and indwelling catheter 32 , but prevents the flow of fluid through sealing valve core 28 when tubes 102 , 104 and 106 are removed from pathways 36 b , 38 b and 40 , respectively. Sealing valve core 28 is formed of a resilient material and contains the three constricted slit-like pathways 36 b , 38 b and 40 for frictionally engaging the outer surfaces of inflation tubes 102 , 104 and 106 , respectively, so that a predetermined force is required to withdraw inflation stylus 100 from sealing valve core 28 . Pathways 36 b , 38 b and 40 define passageways through which inflation tubes 102 , 104 and 106 , respectively, may be inserted without imparting damage to sealing valve core 28 .
Sealing valve assembly 26 comprises sealing valve core 28 , indwelling catheter 32 , and a sealing plug (not shown). Sealing valve core 28 has the general cross-sectional configuration as inflated annular enclosure 14 , and is substantially concentric with inflated annular enclosing layer 12 . Sealing valve core 28 has an outside diameter which is slightly smaller than the diameter of inflated annular enclosure 14 , allowing for additional thickness contributed by annular enclosing layer 12 adjacently enclosing sealing valve core 28 . The additional thickness is crucial during loading nuclear prosthesis 10 onto delivery apparatus 200 . Sealing valve core 28 is preferably fabricated by molding from implantable grade elastomeric material (not shown), such that when an in-situ curable rubber such as RTV liquid silicon or other suitable RTV liquid elastomer is injected in-situ into annular enclosure 14 , a strong bond is formed between the thermoset silicon of sealing valve core 28 and in the in-situ cured rubber to create a unified load-bearing cushion. Preferably, both sealing valve core 28 and the in-situ curable rubber have a similar modulus of elasticity.
Referring to FIGS. 11A and 11B , sealing valve core 28 detachably mounted on the distal end of inflation stylus 100 is shown. Inflation tubes 102 , 104 and 106 at the distal end of inflation stylus 100 are inserted through pathways 36 b , 38 b and 40 , respectively, of sealing valve core 28 . In this configuration, side pore 102 a of annular inlet tube 102 and side pore 104 a of annular outlet tube 104 are in alignment with inlet port 36 a and outlet port 38 a , respectively, of the sealing valve core 28 . Pathways 36 b , 38 b and 40 in sealing valve core 28 are substantially collapsible such that they take the form of three elongated slits prior to insertion of inflation tubes 102 , 104 and 106 therein.
Upon insertion of inflation tubes 102 , 104 and 106 through pathways 36 b , 38 b and 40 , respectively, detachable fluid-tight engagement is achieved between inflation tubes 102 , 104 and 106 of inflation stylus 100 , and annular enclosing layer 12 and nuclear enclosing layer 22 . Pathways 36 b , 38 b and 40 frictionally engage the outer surfaces of inflation tubes 102 , 104 and 106 , obviating the danger of leakage or dislodgement during the pressuring and inflation of nuclear prosthesis 10 , as will discussed in more detail hereinafter.
Referring to FIGS. 5 through 9 , 11 A and 11 B, sealing valve core 28 forms an annular slot 28 b , which extends the outer radial circumference of sealing valve core 28 . Therefore, annular slot 28 b is adjacent both inner margin 16 of annular enclosing layer 12 and outer margin 18 of annular enclosing layer 12 . Sealing valve core 28 further forms a nuclear slot 28 a within annular slot 28 b along the surface of sealing valve core 28 adjacent inner margin 16 of enclosing layer 12 . Annular slot 28 b and nuclear slot 28 a are adapted to receive and retain inner margin 16 of annular enclosing layer 12 , respectively, as well as a surrounding retaining ring 30 . Thus, along inner margin 16 , annular slot 28 b and nuclear slot 28 a define a nuclear mounting region 28 d , which receives annular enclosing layer 12 and retaining ring 30 therein. Annular slot 28 b is adapted to receive and retain outer margin 18 of annular enclosing layer, as well as retaining ring 30 . Therefore, along outer margin 18 , annular slot 28 b defines an annular mounting region 28 c for receiving and retaining outer margin 18 of enclosing layer and retaining ring 30 . The lateral ridges of annular slot 28 b along outer margin 18 of annular enclosing layer 12 mate with a flat distal tip of release cannula 206 of delivery apparatus 200 such that when release cannula 206 is held stationary and inflation stylus 100 is retracted, release cannula 206 urges sealing valve core 28 to detach from inflation stylus 100 .
Referring to FIGS. 2 , 3 , 4 , and 8 , nuclear structure 21 comprises nuclear enclosing layer 12 , nuclear enclosure 24 and indwelling catheter 32 . Nuclear enclosure 24 is defined by the inflatable nuclear enclosing layer 22 , which is bonded about the periphery of indwelling catheter 32 . Indwelling catheter 32 is comprised of a catheter body having a bulbous portion 32 b disposed on the proximal end 32 c of indwelling catheter 32 , which is affixed to inner margin 16 of annular enclosing layer 12 , and extends within sealing valve core 28 . Nuclear enclosing layer 22 is bonded to indwelling catheter 32 at a connector terminal 22 b . Connector terminal 22 b is defined by neck portion 22 a receiving and tightly bonding to the body of indwelling catheter 32 at a predetermined distance from proximal end 32 c and bulbous portion 32 b of indwelling catheter 32 , and a retaining collar 22 c receiving and crimping to neck portion 22 a and indwelling catheter 32 to provide a fluid-tight seal to nuclear enclosing layer 22 .
A fluid-tight seal is formed between indwelling catheter 32 and neck portion 22 a of the nuclear enclosing layer 22 by applying a layer of adhesive material (not shown) between indwelling catheter 32 and neck portion 22 a of nuclear enclosing layer 22 and crimping retaining collar 22 c over indwelling catheter 32 and neck portion 22 a to form the sealed connector terminal 22 b . Preferably, indwelling catheter 32 and the inner surface of neck portion 22 a are thermally and chemically similar, allowing a permanent bond to be performed.
In a preferred embodiment, a polymeric insert (not shown) formed of a mutually bondable material may be interposed between the outer surface of indwelling catheter 32 and inner surface of neck portion 22 a of nuclear enclosing layer 22 during the manufacturing process; thus providing for a more durable structural integrity of the attachment. The entire connector terminal 22 b including retaining collar 22 c , which is placed around neck portion 22 a of nuclear enclosing layer 22 , is then thermally processed and crimped to sealably bond neck portion 22 a of nuclear enclosing layer 22 to indwelling catheter 32 . Retaining collar 22 c tapers proximally for ease of insertion and bonding into nuclear slot 28 a of nuclear mounting region 28 b . Indwelling catheter 32 is relatively stiff and may be formed from polyurethane or polyethylene material (not shown) and may include a braided or helically wound wire reinforcing layer (not shown) to resist kinking. In a preferred embodiment, indwelling catheter 32 is formed by extruding a plurality of layers (not shown), including a suitably bondable outer layer (not shown) into a tubular form.
A seal plug (not shown) is inserted into indwelling catheter 32 for obstructing the lumen of indwelling catheter 32 after inflation of nuclear enclosure 24 is complete. The seal plug is prevented from being dislodged from the lumen of indwelling catheter 32 by the constriction of the slit-like pathway 40 of sealing valve core 28 following retraction of inflation stylus 100 .
Referring to FIGS. 1 through 3 , and FIGS. 1B through 3C , annular enclosing layer 12 has a doughnut-configuration with a substantially concave inner margin 16 and a substantially convex outer margin 18 , providing for inward folding of the concave inner margin 16 , forming a substantially “C” shaped flat band upon deflation of nuclear prosthesis 10 . The substantially “C” shaped flat band configuration of the deflated annular enclosing layer 12 facilitates wrapping annular enclosing layer 12 around the collapsed nuclear enclosing layer 22 and indwelling catheter 32 . This configuration also provides for interlocking of nuclear enclosing layer 22 within annular enclosing layer 22 when nuclear prosthesis 10 is inflated.
Annular enclosing layer 12 is preferably made from a polymeric material and defines a fluid-tight annular enclosure 14 , which is inflatable with an in-situ curable rubber. Annular enclosing layer 12 is preferably semi-compliant. Desirable attributes of annular enclosing layer 12 are not necessarily identical to desirable attributes for medical balloon catheters (not shown), which are used extensively in medical applications such as angioplasty, valvuloplasty, urological procedures and tracheal or gastric intubation.
For example, non-compliance and high tensile strength are less crucial in the case of the present invention's annular enclosing layer 12 of nuclear prosthesis 10 . Annular enclosing layer 12 is not expected to be subjected to high bursting pressures because annular enclosing layer 12 is filled with curable in-situ rubber that is deformable, and because nuclear prosthesis 10 is contained within the confines of a closed space bordered by the native vertebral end-plates of the patient. Furthermore, annular enclosing layer 12 is disposed between annular reinforcement band 20 and nuclear enclosing layer 22 , which restrain over-inflation of annular enclosing layer 12 , thus further making non-compliance and high tensile strength less crucial. The thickness of the membrane (not shown) of which annular enclosing layer 12 is made need only be thick enough to provide a fluid-tight barrier to leakage of in-situ cured rubber. Accordingly, a thin membrane of 20 to 60 microns may be used to construct annular enclosing layer 12 .
On the other hand, long-term structural integrity, moisture resistance (to avoid degeneration and to provide some protection to the rubber within annular enclosure 14 ) is of paramount importance to ensure durability. Other desirable attributes include kink resistance, low wall thickness, low tendency for pinholing, and ease of bonding and coating to other compounds.
Referring to FIGS. 4 through 9 , 11 A and 11 B, sealing valve core 28 of the present invention is adapted to be disposed within annular enclosure 14 and is bondable to annular enclosing layer 12 by heat fusion, ultrasonic welding, hot mold bonding, crimping, or other similar bonding methods known in the art. Adhesive layers (not shown) may be used advantageously in combination to bond sealing valve core 28 of sealing valve assembly 26 to annular enclosing layer 12 , although when the polymer material (not shown) of which sealing valve core 28 of sealing valve assembly 26 and annular enclosing layer 12 are made are similar, adhesives may be unnecessary.
As annular enclosing layer 12 is made from semi-compliant material (not shown), inflating annular enclosure 14 tends to exert a peel-away force on the bond between annular enclosing layer 12 and sealing valve core 28 of sealing valve assembly 26 . To avoid this potential problem, nuclear slot 28 a and annular slot 28 b are formed along the surface of sealing valve core 28 adjacent inner margin 16 of annular enclosing layer 12 , and are adapted to receive a portion of inner margin 16 of annular enclosing layer 12 and a portion of inner layer 30 a of retaining ring 30 . Annular slot 28 b extends the radial circumference of sealing valve core 28 . On the surface of sealing valve core 28 adjacent outer margin 18 of annular enclosing layer 12 , annular slot 28 b receives a portion of outer margin 18 and a portion of outer layer 30 b of retaining ring 30 . In a preferred embodiment, the method of securing sealing valve core 28 of sealing valve assembly 26 to annular enclosing layer 12 includes the use of retaining ring 30 positioned over and crimped tightly around annular enclosing layer 12 such that inner layer 30 a of retaining ring 30 is adjacent nuclear slot 28 a , and outer layer 30 b of retaining ring 30 is adjacent annular slot 28 b . The entire connection of sealing valve core 28 , annular enclosing layer 12 and retaining ring 30 is then thermally pressed to form a sealably bonded sealing valve core 28 within annular enclosure 14 resistant to separation from annular enclosing layer 12 during inflation.
Preferably, both sealing valve core 28 and the in-situ curable rubber injected into annular enclosure 14 are comprised of the same rubber material. When the in-situ curable rubber injected in annular enclosure 14 during inflation of nuclear prosthesis 10 solidifies, it bonds to sealing valve core 28 . The result is that the distinction between sealing valve core 28 and the curable rubber disappears, and an integral annular enclosure 14 of unitary construction is created.
Referring to FIGS. 4 , 9 , 10 and 17 through 19 , annular reinforcement band 20 is disclosed. Annular reinforcement band 20 of the present invention is preferably a semi-compliant multi-layered bio-compatible textile structure that provides a detent to maximal stretching of the circumference of nuclear prosthesis 10 . Various parameters and properties of annular reinforcement band 20 may be adjusted to provide longitudinal flexibility and stretch, radial compliance, and kink resistance of annular reinforcement band 20 . Such variations include varying the materials from which the fibers making up the layers 20 a , 20 b and 20 c of annular reinforcement band 20 are formed, varying fiber density, varying fiber denier, varying braiding angles, varying the number of strands per filament, and varying heat-set conditions. These parameters are tailored to provide the desirable function required of a particular layer of annular reinforcement band 20 , depending on the layer's position in annular reinforcement band 20 . Generally, outer layers 20 a should be substantially less compliant, and compliance the annular reinforcement band 20 should increase through intermediate layers 20 b and inner layer 20 c.
In a preferred embodiment, annular reinforcement band 20 is a three-dimensional structure that is formed by extending and interlocking at least one yarn of each layer of annular reinforcement band 20 with the adjacent layers. The multi-layered textile annular reinforcement band 20 shows a gradation of properties between its inner layers and outer layers. Referring to FIG. 9 and FIGS. 17 through 19 , at least one, and preferably more than one outer layers 20 a are preferably made of a warp knitted pattern of biocompatible fibers. This gives outer layers 20 a of annular reinforcement band 20 the advantage of velour, high porosity surface, enhancing tissue in-growth, as well as resisting unraveling. The fibers of outer layers 20 a may be of low denier and may be textured or non-textured.
At least one, and preferably more than one intermediate layers 20 b may be formed from biocompatible fibers forming a plurality of loops which follow helical or spiral paths, which may also be wavy or serpentine, contributing to the compliance of annular reinforcement band 20 . The fibers of intermediate layers 20 b preferably include monofilaments of larger denier formed of durable material, such as polyethylene teraphthlate in braided or jersey patterns providing a load-bearing component, resistant to torsion and overstretching. The fibers in intermediate layers 20 b may be chosen to perform a gradation of properties between the mid or equatorial region of annular reinforcement band 20 towards the upper and lower axial margins thereof. In a preferred embodiment, the equatorial section of annular reinforcement band 20 is formed of monofilaments that are thicker, stronger and less compliant filaments, with tapering of these properties towards the upper and lower margins of annular reinforcement band 20 . This renders annular reinforcement band 20 more resistant to kinking during stretching and radial compression of nuclear prosthesis 10 necessary to load nuclear prosthesis 10 within delivery apparatus 200 .
Inner layer 20 c of annular reinforcement band 20 is formed from more compliant and thinner biocompatible yarn. In one embodiment, inner layer 20 c may include a fusible fiber (not shown) having a low melting temperature, heat-fusing annular reinforcement band 20 to an innermost layer of intermediate layers 20 b and annular enclosing layer 12 , enhancing ravel and fray resistance. In the preferred embodiment, annular reinforcement band 20 is not bonded to annular enclosing layer 12 .
In the preferred embodiment of the present invention, synthetic yarns (not shown) which are not degraded by the body are used to form the textile annular reinforcement band 20 . The yarns may be of the monofilament, multifilament or spun type, used in different combinations. Monofilaments are preferred in intermediate layers 20 b , providing for a lower volume structure with comparable strength to the fiber bundles of the multifilament fibers. Multifilaments are preferred along inner layer 20 c and outer layers 20 a to increase flexibility. The yarns may be flat, textured, twisted, shrunk, or pre-shrunk. As discussed above, the yarn type and yarn denier for a particular layer of the textile annular reinforcement band 20 may be chosen to meet the design requirements of annular reinforcement band 20 .
Referring to FIGS. 2 , 3 and 4 , nuclear enclosing layer 22 is essentially a discoid multilayered medical balloon which is fabricated by forming a plurality of polymeric layers (not shown) that converge on neck portion 22 a of connector terminal 22 b , adapted for fluid-tight bonding to indwelling catheter 32 . Conventional balloon fabricating techniques are utilized to form a composite nuclear enclosing layer 22 of different polymeric materials (not shown) that are subjected to a stretch blow-molding operation in a heated mold (not shown). The resulting nuclear enclosing layer 22 of the present invention provides superior burst strength, superior abrasion resistance, and superior structural integrity, without significantly impairing the overall compressibility and gas-cushioning function of nuclear prosthesis 10 .
Long-term maintenance of a gas cushion in an inflated state is perhaps the most demanding requirement of nuclear enclosure 24 . Various approaches may be taken, including melt-blending the materials making up nuclear enclosing layer 22 and the use of multilayer fiber reinforced balloon structures (not shown) to make nuclear enclosing layer 22 .
Referring to FIGS. 2 , 3 , 4 and 8 , nuclear enclosing layer 22 has a neck portion 22 a which is bonded to indwelling catheter 32 , forming a secure connector terminal 22 b . Indwelling catheter 32 has a proximal end 32 c including bulbous portion 32 b which is adapted to be coupled to nuclear access tube 106 inflation stylus 100 , which is inserted through pathway 40 in sealing valve core 28 of sealing valve assembly 26 . Bulbous portion 32 b defines a bulbous portion that snaps into a corresponding bulbous region 32 e in sealing valve core 28 . Bulbous portion 32 b is sealingly affixed to the corresponding bulbous portion 32 e of sealing valve core 28 , forming a fluid-tight bond with sealing valve core 28 . Proximal end 32 c of indwelling catheter 32 is in fluid communication with the distal end of nuclear access tube 106 , within sealing valve core 28 .
Nuclear enclosing layer 22 is sealingly mounted on the shaft of indwelling catheter 32 . Preferably, neck portion 22 a of nuclear enclosing layer 22 is thermally or meltably bonded to indwelling catheter 32 . Connector terminal 22 b and indwelling catheter 32 are all preferably made of melt compatible material. Connector terminal 22 b may utilize a tie layer or “retaining collar” 22 c formed of mutually bondable material that is slipped over neck portion 22 a of nuclear enclosing layer 22 . Retaining collar 22 c is heated and crimped to simultaneously meltably join neck portion 22 a of nuclear enclosing layer 22 , retaining collar 22 c , and indwelling catheter 32 , making connector terminal 22 b a permanent fluid-tight seal.
Indwelling catheter 32 defines a lumen with side pore 32 a therein located proximal to closed tip 32 d of indwelling catheter 32 . After inflating nuclear prosthesis 10 within the nuclear space void of a patient, the lumen of indwelling catheter 32 can be permanently obstructed by a small sealing plug (not shown) introduced through proximal end 32 c of indwelling catheter 32 , and pushed into position with a guidewire (not shown) or other suitable positioning device. Pathway 40 of sealing valve core 28 collapses upon removal of inflation stylus 100 , preventing back-up of the sealing plug within indwelling catheter 32 .
Referring to FIGS. 1D , 2 D and 3 D, delivery apparatus 200 is disclosed. Prior to insertion of delivery apparatus 200 into the patient, a percutaneous access device (not shown) provides an access way or annular fenestration (not shown) into the inter-vertebral disc space of the patient, which is held open by an access cannula 202 . Any percutaneous access device used for minimally invasive percutaneous procedures can be used to create the annular fenestration. Generally, such percutaneous access devices comprise a plurality of telescopically arranged cannulas (not shown). After creation of the annular fenestration, delivery apparatus 200 can be delivered within access cannula 202 . Delivery apparatus 200 comprises a delivery cannula 204 with nuclear prosthesis 10 loaded therein, and a release cannula 206 . Delivery apparatus 200 , including nuclear prosthesis 10 and delivery cannula 204 which houses nuclear prosthesis 10 is provided, assembled and hermetically sealed so that loading or handling of nuclear prosthesis 10 is unnecessary during insertion and inflation thereof within the nuclear space void of the patient.
Still referring to FIGS. 1D , 2 D, and 3 D, delivery apparatus 200 of the present invention has oval inner and outer cross-section conforming to the cross sections of access cannula 202 . Delivery apparatus 200 comprises a delivery cannula 204 having a wall of uniform thickness defining a cylindrical inner passage having a substantially oval cross section, and a substantially oval release cannula 206 located within the oval, cylindrical inner passage of delivery cannula 204 . Inflation stylus 100 is slidably received within the oval release cannula 206 .
Delivery apparatus 200 is slidably received internally of the access cannula 202 , and is selectively extendible and retractable relative to access cannula 202 to facilitate proper placement of nuclear prosthesis 10 through the annular fenestration into the disc space void.
Referring to FIGS. 10 through 11B , delivery cannula 204 of delivery apparatus 200 encloses release cannula 206 , which is telescopically slidable over inflation stylus 100 . As previously discussed, inflation stylus 100 includes three inflation tubes 102 , 104 and 106 extending from its tip. Inflation tubes 102 , 104 and 106 are frictionally engaged to pathways 36 b 38 b and 40 (respectively) of sealing valve core 28 . In a preferred embodiment, nuclear access tube 106 has a bulbous ridge 106 b formed at its mid aspect that mates with a corresponding bulbous region 40 b formed along passageway 40 . The frictional engagement, as well as the engagement of bulbous ridge 106 b with the bulbous region 40 b provides a firm attachment of inflation stylus 100 to sealing valve core 28 , while allowing inflation tubes 102 , 104 and 106 to be withdrawn when sufficient force is applied to it.
The amount of force required to withdraw inflation stylus 100 from nuclear prosthesis 10 may be chosen by selecting the rigidity and modulus of elasticity forming sealing valve core 28 as well as selecting the size and geometry of the pathways 36 b , 38 b and 40 and bulbous ridge 106 b . Generally, the amount of force required to release inflation stylus 100 from sealing valve core 28 must be more than the maximum inflation pressure experienced at the connection during inflation of nuclear prosthesis 10 . It may be difficult to precisely control the force required to withdraw inflation stylus 100 from sealing valve core 28 .
As may be appreciated, if this force is too great, sealing valve core 28 may be dislodged through the annulotomy, possibly causing tearing of the native annulus fibrosis. If the force required to withdraw inflation stylus 100 from sealing valve core 28 is too small, inflation stylus 100 may become prematurely detached from sealing valve core 28 during pressurizing and inflation of nuclear prosthesis 10 .
Referring to FIGS. 10 through 12 , in a preferred embodiment, the release of inflation stylus 100 from sealing valve core 28 is obtained by utilizing release cannula 206 placed coaxially around inflation stylus 100 . Release cannula 206 has a thick wall and a diameter smaller than the outer diameter of sealing valve core 28 , such that its distal end engages sealing valve core 28 to, in effect, push sealing valve core 28 away from inflation stylus 100 . A screw drive mechanism (not shown) is threadedly engaged with and coupled to the proximal end (not shown) of inflation stylus 100 and release cannula 206 to achieve smooth, efficient, and predictable disengagement of inflation stylus 100 from the sealing valve core 28 .
The screw drive mechanism provides a mechanical advantage for withdrawing inflation stylus 100 from sealing valve core 28 at a controlled rate. A coupler (not shown) at the proximal end of inflation stylus 100 is adapted to engage the proximal end (not shown) of release cannula 206 to controllably extend and retract inflation stylus 100 and control its maximum travel. This can be done while the tip of release cannula 206 holds sealing valve core 28 stationary within annular enclosure 14 . The extension and retraction capabilities of inflation stylus 100 (in unison or independent of release cannula 206 ) facilitate proper deployment and detachment of nuclear prosthesis 10 within the nuclear space void. Withdrawal of inflation stylus 100 may be achieved by merely turning a knob (not shown) on the screw drive mechanism, which causes inflation stylus 100 to retract axially with respect to release cannula 206 , while sealing valve core 28 is held in place by the tip of release cannula 206 , thereby selectively screw-engaging or disengaging release cannula 206 .
The retracting motion continues until inflation tubes 102 , 104 and 106 are completely disengaged from pathways 36 b , 38 b and 40 , respectively, of sealing valve core 28 . The screw drive mechanism may include a worm drive (not shown) that mates with teeth (not shown) formed on the exterior surface of inflation stylus 100 and release cannula 206 . Clearly, a wide variety of mechanical linkages are available to extend and retract inflation stylus 100 and release cannula 206 . It is particularly advantageous to provide a mechanism which allows independent, as well as linked and coordinated movements.
The knob may also be rotationally twisted in one direction during the loading of nuclear prosthesis 10 into delivery apparatus 200 . In this case, release cannula 206 and inflation stylus 100 are retracted as one unit into delivery apparatus 200 , pulling nuclear prosthesis 10 through a loading apparatus 300 and progressively radially compressing nuclear prosthesis 10 to a reduced-radius state until it is fully loaded within delivery cannula 204 of delivery apparatus 200 . When the knob is rotationally twisted in the opposite direction, release cannula 206 and inflation stylus 100 extend as one unit extruding nuclear prosthesis 10 from the tip of delivery cannula 204 to achieve predictable and controlled incremental deployment within the nuclear space void.
Referring to FIGS. 1A , 2 A and 3 A, loading apparatus 300 has a first loading block 302 and a second loading block 304 traversed by mirror-image funnel-shaped passageways 306 and 308 , respectively. The distal end of delivery apparatus 200 fits snugly but slidably within loading port 316 at a front end of first loading block 302 . The apposing ends of first loading block 302 and second loading block 204 have the general size and configuration of an inflated nuclear prosthesis 10 . Each funnel shaped passageway 306 and 308 of first loading block 302 and second loading block 304 , respectively tapers down within each loading block 302 and 304 to a second, smaller configuration which has the general cross-sectional oblong configuration of delivery cannula 204 of delivery apparatus 200 , and runs for a short distance in loading blocks 302 and 304 , forming a smooth transition with the inner margin of delivery cannula 204 at the loading port 316 of first loading block 302 .
Funnel passageways 306 and 308 of loading apparatus 300 define a tapered diamond-shaped space that geometrically and plastically deforms nuclear prosthesis 10 from a generally round, inflated configuration, as it is being deflated and pulled in opposing directions (as indicated by direction arrows 400 and 402 ) of the radial axis through the tapered funnel shaped passageways 306 and 308 , and then loaded into delivery cannula 204 of delivery apparatus 200 , which has been inserted into loading port 316 of first loading block 302 .
Referring to FIGS. 1A through 3C , as nuclear prosthesis 10 is pulled and stretched in opposing directions 400 and 402 within the diamond-shaped passageway defined by funnel shaped passageways 306 and 308 , nuclear prosthesis is progressively radially approximated to a reduced-radius state. Simultaneously, annular enclosure 14 is deflated, approximating inner margin 16 and outer margin 18 of annular enclosing layer 12 into the thin substantially “C” shaped configuration, which assumes a more acute curvature as nuclear prosthesis 10 is stretched.
Annular enclosing layer 12 is stretched in a radial direction diametrically opposite to loading port 316 and delivery apparatus 200 by a traction band 322 removably wrapped around annular enclosing layer 12 at a position diametrically opposite the position of loading port 316 . In one embodiment, removable traction band 322 is a rubber band. However, any suitable band made of any suitable material can be used as traction band 322 , so long as it allows for removable attachment to annular enclosing layer 12 and is capable of stretching nuclear prosthesis 10 in a direction diametrically opposite the direction delivery apparatus 200 stretches nuclear prosthesis 10 . As nuclear prosthesis 10 reaches the small end of the diamond-shaped passageway defined by funnel shaped passageways 306 and 308 , annular enclosing layer 12 is wrapped tightly and folded compactly around nuclear enclosing layer 22 and indwelling catheter 32 , into the smallest possible cross-section, and is withdrawn into delivery cannula 204 of delivery apparatus 200 . The folded nuclear prosthesis 10 fits loosely within delivery cannula 204 , allowing achievement of unhindered deployment into the nuclear space void.
The inner surfaces of loading blocks 302 and 304 are preferably lined with a water-soluble lubricious hydrophilic coating (not shown) to lubricate the contact surfaces between loading blocks 302 and 304 and nuclear prosthesis 10 during loading thereof onto delivery apparatus 200 .
During the loading process, nuclear prosthesis 10 is deflated, stretched and radially compressed so as to adopt a low-profile configuration within the delivery cannula. Referring to FIGS. 3A and 3D , folded nuclear prosthesis 10 is shown releasably attached to the distal end of inflation stylus 100 , which is surrounded by release cannula 206 and housed within the delivery cannula 204 . Delivery apparatus 200 passes through access cannula 202 . As previously discussed, nuclear prosthesis 10 is secured to inflation stylus 100 , by way of inflation tubes 102 , 104 and 106 projecting from the distal tip of inflation stylus 100 and inserted into corresponding passageways 36 b , 38 b and 40 , respectively, in sealing valve core 28 of nuclear prosthesis 10 . When the inflation stylus 100 —release cannula 206 assembly is retracted within delivery cannula 204 , the loaded nuclear prosthesis 10 is pulled into the delivery cannula 204 .
It should be appreciated by one skilled in the art that once the deflated nuclear prosthesis 10 is delivered into the nuclear space void, an inflation-assisting device (not shown) or fluid delivery apparatus (not shown) introduces the in-situ curable rubber into annular enclosure 14 and the liquid and/or gas into nuclear enclosure 24 . It should be understood to one of ordinary skill in the art that any device, apparatus and/or system suitable for injecting fluid can be used to inflate nuclear prosthesis 10 could be used. Furthermore, fluid can be injected into nuclear prosthesis 10 manually using a syringe (not shown) connected to the tubes 102 , 104 and 106 of inflation stylus 100 .
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon the reference to the description of the invention. It is therefore contemplated that the appended claims will cover such modifications that fall within the scope of the invention.
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An inter-vertebral disc prosthesis intended for percutaneous deployment comprises an expandable annular enclosure and an expandable nuclear enclosure. The expandable annular enclosure incorporates a reinforcing annular band along its periphery and is filled with in-situ curable rubber. The expandable nuclear enclosure is filled with a gas. The nuclear prosthesis further incorporates a novel, integrally molded sealing valve assembly and is stretchable and collapsible into a minimal profile for ease of insertion into a specially designed delivery cannula, and is inflation-assisted expandable into an inter-vertebral disc in which complete percutaneous nuclectomy has been performed.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent application Ser. No. 12/467,051, filed on May 15, 2009, which is a divisional application of U.S. patent application Ser. No. 10/555,628, the contents of which are incorporated herein in its entirety and from which priority is claimed.
FIELD OF THE INVENTION
[0002] A barium salt of the S-enantiomer of omeprazole which is (S)-5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)-methyl]sulfinyl]-1H-benzimidazole is provided. Further, processes for preparing the barium salt, pharmaceutical compositions comprising the salt and a method of treatment or prevention of gastrointestinal ulcers comprising administration of the salt are provided.
BACKGROUND OF THE INVENTION
[0003] Omeprazole is a gastric acid secretion inhibitor, useful as an anti-ulcer agent. U.S. Pat. No. 5,714,504 describes alkaline salts of (S)-omeprazole, such as sodium, magnesium, lithium, potassium, calcium or tetraalkylammonium salts. However, only the preparation of sodium and magnesium salts of (S)-omeprazole has been exemplified, besides (S)-omeprazole freebase in this patent. The potassium salt of (S)-omeprazole has been described as prepared in WO 98/54171 and WO 00/44744. The commercially available magnesium salt of (S)-omeprazole is used for treating and preventing peptic ulcers, gastroesophageal reflux disease (GERD or heartburn), erosive esophagitis, other conditions involving excessive stomach acid production, and for treating bacterial infections caused by helicobacter pylori.
SUMMARY OF THE INVENTION
[0004] Herein is provided the barium salt of (S)-omeprazole, that is, (S)-omeprazole barium. Another aspect relates to (S)-omeprazole barium in a crystalline form. Yet another aspect relates to (S)-omeprazole barium in an amorphous form.
[0005] In yet another aspect, a process for preparing (S)-omeprazole barium is provided, which comprises contacting (S)-omeprazole freebase or its sodium/potassium salt with barium salt of an acid in a suitable solvent to form (S)-omeprazole barium, wherein the process is carried out in the presence of a base whenever (S)-omeprazole freebase is used.
[0006] Alternatively, (S)-omeprazole barium may be prepared by a process which comprises contacting (S)-omeprazole freebase with barium hydroxide in a suitable solvent. Also, processes for preparing (S)-omeprazole barium in amorphous form are provided, which comprise concentrating a solution containing (S)-omeprazole barium to dryness or by spray drying the solution.
[0007] Further aspects include methods for treating or preventing gastrointestinal ulcers which comprise administering (S)-omeprazole barium, or a pharmaceutical composition that comprises (S)-omeprazole barium, along with pharmaceutically acceptable excipients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Fig. I illustrates the arrangement of Figs. IA and IB with respect to each other for displaying an x-ray diffraction (XRD) pattern of the (S)-omeprazole barium in crystalline form prepared according to the process of Example 1.
[0009] Figs. IA and IB are the x-ray diffraction patterns of Fig. I.
[0010] Fig. II is an infrared (IR) spectra of the (S)-omeprazole barium in crystalline form prepared according to the process of Example 1.
[0011] Fig. III illustrates the arrangement of Figs. IIIA and IIIB with respect to each other for displaying an x-ray diffraction pattern of the (S)-omeprazole barium in crystalline form prepared according to the process of Example 2.
[0012] Figs. IIIA and IIIB are the x-ray diffraction patterns of Fig. III.
[0013] Fig. IV is an x-ray diffraction pattern of the (S)-omeprazole barium in amorphous form prepared according to the process of Example 3.
[0014] Fig. V is an infrared spectra of the (S)-omeprazole barium in amorphous form prepared according to the process of Example 3.
[0015] Fig. VI is an x-ray diffraction pattern of the (S)-omeprazole barium prepared according to the process of Example 4.
[0016] Fig. VII is an infrared spectra of the (S)-omeprazole barium prepared according to the process of Example 4.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The term “(S)-omeprazole barium” as used herein means any salt comprising (S)-omeprazole anions and barium cations. For instance, solid as well as dissolved forms are included, and so are crystalline and amorphous forms. (S)-omeprazole barium may exist in an anhydrous and/or solvent-free form or as a hydrate and/or a solvate.
[0018] The expression “(S)-omeprazole,” as used herein, refers to an omeprazole-containing material which is substantially free of the R-enantiomer of omeprazole, for example, it has an enantiomeric excess of 80%, or for example an enantiomeric excess of 90%. In some particular embodiments, S-omeprazole is in enantiomeric excess of at least about 95%, or at least about 98%, or at least about 99.5%, or at least about 99.8%.
[0019] Further, the term “(S)-omeprazole barium,” as used herein, encompasses stoichiometric as well as non-stoichiometric ratios of (S)-omeprazole anion and barium cation. The ratio of (S)-omeprazole to barium is not required to be 1:1 in order to be termed (S)-omeprazole barium. In a particular embodiment, (S)-omeprazole barium is formed as a salt having a 2:1 molar ratio between (S)-omeprazole anion and barium cation even when an excess of (S)-omeprazole or an excess of barium salt of an acid is used in the salt formation.
[0020] (S)-omeprazole barium obtained in both crystalline and amorphous forms is non-hygroscopic. An amorphous form may be advantageous in comparison with the crystalline form as it can be obtained in a finely powdered form with better solubility properties.
[0021] Examples of bases which may be used in the process for preparing (S)-omeprazole barium using (S)-omeprazole freebase include alkali metal hydroxides such as sodium hydroxide or potassium hydroxide, alkali metal carbonates such as sodium carbonate or potassium carbonate, alkali metal bicarbonates such as sodium bicarbonate, and ammonium hydroxide.
[0022] The barium salt of an acid to be used in the process can be the salt of any inorganic or organic acid. Examples of such salts include barium chloride, barium nitrate, barium sulphate, barium phosphate, barium carbonate, barium oxalate, barium acetate, barium lactate, barium succinate, barium citrate, and barium tartrate.
[0023] Examples of suitable solvents for carrying out the salt-forming processes include water, ketones such as acetone and methyl isobutyl ketone, alcohols such as methanol, ethanol and isopropanol, esters such as ethyl acetate and isopropyl acetate, chlorinated hydrocarbons such as methylene chloride and ethylene dichloride, cyclic ethers such as dioxan and tetrahydrofuran, nitriles such as acetonitrile, dipolar aprotic solvents such as dimethylsulfoxide and dimethylformamide, and mixtures thereof.
[0024] In water and methanol the reactants are more soluble than the (S)-omeprazole barium product. In this way, the salt-forming reaction is accompanied by spontaneous precipitation of the produced barium salt out of the solution. While such a precipitation in methanol gives crystalline (S)-omeprazole barium, in water the amorphous form is obtained.
[0025] Alternatively, the precipitation may be facilitated by reducing the volume of the solution and/or by adding an antisolvent, that is, a solvent in which the (S)-omeprazole barium is insoluble or sparingly soluble. The precipitation can also be induced by reducing the temperature of the solvent, especially if the initial temperature at contact is elevated.
[0026] Examples of anti solvents that may be added to precipitate out (S)-omeprazole barium include aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as xylene and toluene; lower alkyl ethers such as diethyl ether, and diisopropyl ether; and mixture(s) thereof.
[0027] The (S)-omeprazole freebase or its sodium/potassium salt to be used in the preparation processes can be obtained by methods known in the art including those described in U.S. Pat. Nos. 5,714,504, 5,948,789, and 6,162,816, and International Patent Applications WO 00/44744, WO 98/54171, and WO 92/08716. The starting (S)-omeprazole freebase or its sodium/potassium salts may be obtained as a solution directly, from a reaction in which S-omeprazole is formed, and used as such.
[0028] The precipitated barium salt may be isolated in a solid state by conventional methods such as filtration or centrifugation, optionally followed by washing and/or drying.
[0029] (S)-omeprazole barium may also be obtained in amorphous form by concentrating the solution of (S)-omeprazole barium to dryness or by spray drying the solution. Solutions of (S)-omeprazole barium may be obtained from the salt-forming reaction in a suitable solvent or by dissolving crystalline (S)-omeprazole barium in a suitable solvent.
[0030] (S)-omeprazole barium is a useful proton pump inhibitor and an antibacterial, and thus can be used to treat any condition that would be benefited by administration of a gastric acid secretion inhibitor. In particular, (S)-omeprazole barium can be used for the treatment or prophylaxis of gastric acid-related diseases and gastrointestinal inflammatory diseases in mammals and man, such as erosive or ulcerative gastroesophageal reflux disease (GERD), gastric ulcer, duodenal ulcer, reflux esophagitis, and gastritis.
[0031] Furthermore, it may be used for treatment of other gastrointestinal disorders where a gastric antisecretory effect is desirable, for example in patients on NSAID therapy, in patients with gastrinomas, and in patients with acute upper gastrointestinal bleeding. It may also be used in patients in intensive care situations, and pre- and post-operatively to prevent acid aspiration and stress ulceration. Further, (S)-omeprazole barium may be useful in the treatment of helicobacter infections and diseases related to these.
[0032] The salt can be administered as a component of a pharmaceutical composition. Accordingly, in a further aspect, there is provided a pharmaceutical composition that comprises (S)-omeprazole barium and pharmaceutically acceptable carriers, diluents or excipients and optionally other therapeutic ingredients. The salt may be conveniently formulated into tablets, capsules, suspensions, dispersions, injectables and other pharmaceutical forms. Any suitable route of administration may be employed for example, peroral or parental.
[0033] In the following section preferred embodiments are described by way of examples to illustrate the process of the invention. However, these are not intended in any way to limit the scope of the present invention. Variants of these examples would be evident to persons ordinarily skilled in the art.
EXAMPLES
General Experimental Details—Powder XRD
[0034] X-Ray Diffraction (XRD) patterns were taken with a diffractometer manufactured by Rigaku Corporation, specifically the model RU-H3R. The goniometer was a CN2155A3, and the X-Ray tube was equipped with Cu target anode. The settings for the divergence slits were 1 0, for the receiving slit 0.15 mm, and for the scatter slit 1 0. The operating power was 40 KV, 100 mA, the scanning speed was 2 deg/min step: 0.02 deg, and the wavelength was 1.5406 A.
General Experimental Details—FT-Infrared
[0035] Infrared spectra were taken with a Perkin Elmer, 16 PC, with scan parameters of 16 scans, 4.0 cm −1 according to the USP 25, general test methods, page 1920. Infrared absorption spectra were obtained by the potassium bromide pellet method.
General Experimental Details—Differential Scanning Calorimetry
[0036] Differential Scanning calorimetry was done by the model DSC821 e, manufactured by Mettler Toledo, with sample weights of 3-5 mg, and the sample temperature range of 25-100° C., heating rate of 1° C./min, nitrogen flow of 80.0 mL/min, with one hole in the crucible.
Example 1
A First Preparation Of (S)-omeprazole Barium in Crystalline Form
[0037] (S)-omeprazole free base (5 g) was added to methanol (25 ml) and stirred at 25-30° C. Barium hydroxide (4.6 g) dissolved in methanol (40 ml) was slowly added to the above solution in 10 minutes at 25-30° C. The reaction mixture was further stirred for 1 to 2 hours, the obtained solid was filtered and washed with methanol. The product was air dried at 40 to 45° C. for 8 to 10 hours to get (S)-omeprazole barium (5.2 g).
[0038] HPLC Purity=98.56%, Chiral Purity by HPLC=99.89%. MC % w/w by KF=4.12%. XRD, IR spectra are as shown in Figure I and II respectively, as shown in the accompanying drawings.
Example 2
[0039] Potassium salt of (S)-omeprazole (10.0 g) was stirred in water (80 ml) and methylene chloride (80 ml). The suspension was cooled to 10 to 15° C. and dilute hydrochloric acid was added to adjust pH to 7.0 to 8.5. The reaction mixture was stirred for 5 minutes. The organic layer was separated and washed with water. The solvent was recovered under reduced pressure at 30-35° C. to obtain an oily residue. Methanol (40 ml) was added, and the mixture stirred for 10 to 15 minutes. Barium hydroxide (9.0 g) dissolved in methanol (90 ml) was slowly added to the above solution in 10 minutes at 25-30° C. The reaction mixture was further stirred for 1 to 2 hours. The solid obtained was filtered, washed with methanol and air dried at 40 to 45° C. for 8 to 10 hours to get (S)-omeprazole barium (8.1 g).
[0040] HPLC Purity=97.98%, Chiral Purity by HPLC=100%. MC % w/w by KF=7.46%. XRD spectrum is as shown in Figure III, as shown in the accompanying drawings. IR spectrum is similar to that shown in Figure II for Example I.
Example 3
Preparation Of (S)-omeprazole Barium in Amorphous Form
[0041] (S)-omeprazole free base (5 g) was added to acetone (60 ml) and stirred at 25-30° C. Barium hydroxide octahydrate (4.6) and water (15 ml) were then added to the above mixture at 25-30° C. The reaction mixture was further stirred for 4 to 5 hours, and then filtered to remove suspended solid material. The solvent was recovered under reduced pressure to obtain the product as a foam. The product was dried at 40 to 45° C. under reduced pressure for 2 to 3 hours to get (S)-omeprazole barium (4.2 g).
[0042] HPLC Purity=99.43%, Chiral Purity by HPLC=99.99%, MC % w/w by KF=2.66%. XRD, IR spectra are as shown in Figure IV and V respectively, as shown in the accompanying drawings.
Example 4
[0043] Potassium salt of (S)-omeprazole (5 g) was dissolved in water (60 ml) at 25-30° C. to get a clear solution. Barium chloride dihydrate (3.2 g) dissolved in water (10 ml) was slowly added to the above solution in 10 minutes at 25-30° C. The reaction mixture was further stirred for 1 to 2 hours, the obtained solid was filtered and washed with water. The product was air dried at 40 to 45° C. for 8 to 10 hours to get (S)-omeprazole barium (3.4 g), MC % w/w by KF=0.10%.
[0044] XRD, IR spectra are as shown in Figure VI and VII respectively as shown in the accompanying drawings.
Example 5
[0045] Crystalline (S)-omeprazole barium (3 g) was added to acetone (60 ml) and stirred at 25-30° C. The solution was then filtered to remove any suspended solid material. The solvent was recovered under reduced pressure at 40 to 45° C. to obtain the product as a foam. The product was dried at 40 to 45° C. under reduced pressure for 2 to 3 hours to get (S)-omeprazole barium (2.5 g). HPLC Purity=99.27%, MC % w/w by KF=2.10%.
[0046] XRD, IR spectra are similar to those shown in Figure IV and V respectively for Example 3.
Example 6
[0047] Crystalline (S)-omeprazole barium (5.0 g) was added to acetone (100 ml) and stirred at 25-30° C. The solution was then filtered to remove any suspended solid material and subjected to spray drying under nitrogen atmosphere (inlet temperature 50 to 60° C. and outlet temperature 40 to 45° C.). The product so obtained was dried at 40 to 45° C. under reduced pressure for 2 to 3 hours to get (S)-omeprazole barium (3.0 g). MC % w/w by KF=1.2%.
[0048] XRD, IR spectra are similar to those shown in Figure IV and V respectively for Example 3.
[0049] While the present invention has been described in terms of its specific embodiments, certain modifications and equivalents will be apparent to those skilled in the art and are intended to be included within the scope of the present invention.
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The invention relates to crystalline barium salt of (S)-omeprazole, which is (S)-5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)-methyl]sulfinyl]-1H-benzimidazole. The invention also relates to processes for preparing crystalline barium salt of (S)-omeprazole and pharmaceutical compositions that include the crystalline barium salt of (S)-omeprazole so prepared.
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FIELD OF THE INVENTION
[0001] The present disclosure generally relates to systems to separate and collect dust particles from gas stream and, more particularly, to dust collectors that remove particulates from high gas flow rate in industrial applications, such as may be used in mobile equipment in applications including street sweepers, sewage vacuum trucks and industrial vacuum trucks where low pressure loss, high separation efficiency, compactness, light weight, and reliability are highly demanded.
BACKGROUND
[0002] Using gas flow to clean and transfer materials is a flexible and convenient process in many industrial applications. However, an associated problem is how to effectively separate and remove fine solid particles (e.g., dust or sand) from the gas stream before exhausting the gas to the atmosphere, or before the gas reaches the power source (e.g., a fan or blower).
[0003] For mobile equipment, such as street sweepers, sewage trucks, and industrial vacuum trucks, this problem is especially challenging. Due to the limited availability of power and space, any dust separation device on mobile equipment should be highly efficient. In general, it should employ a low pressure drop, or decrease in suction power. Further considerations tend toward a compact and lightweight system, taking up little space with a reduced payload. Any dust separation device or system on mobile equipment should be reliable and have little down-time.
[0004] A common cyclone may cause a 12 to 14 inch water column pressure drop at a flow velocity of 70 feet per second. Such a device would not be very suitable for use on a street sweeper, where the maximum suction power is generally a 48 inch water column.
[0005] Many devices for removing materials entrained in a gas flow currently exist. Using filters can usually achieve high separation quality, but filters are also generally associated with high pressure loss, high cost, and maintenance. Filters may also have problems when dealing with high temperature gases, depending on the material of the filter. In comparison, mechanical separation devices such as inertial inlet separators and cyclones have many advantages. They are simple, low-cost, and generally maintenance-free. But while an inertial inlet separator is the simplest, it is generally limited by low separation efficiency and larger space demands to settle and collect dust.
[0006] Cyclones are another option. Most widely-used cyclones are reverse flow type, as shown in FIG. 1 of this disclosure. The dust-laden gas stream is introduced tangentially into a cylindrical barrel or chamber to generate rotational flow moving downward. Larger or heavier particles are forced to move outwardly to the walls and then fall into the dust collector at the bottom. In this version, the cleaned gas stream will then reverse direction at 180-degrees to exit from a tube at the top end. This type of cyclone is well-known in the art for its high efficiency, typically on the order of 90% or greater, depending on the application. However, one drawback of all traditional cyclones is that the high efficiency comes at the price of high pressure drop, especially in high flow velocity situations. To overcome this problem, one solution is to use multiple cyclones in parallel arrangement to reduce the flow to each cyclone so that the pressure loss is reduced. For this reason, it is not surprising to see an industrial vacuum truck having a row of 4 to 6 cyclones attached around the debris body to handle a flow in the range of 3000 to 5000 cubic feet per minute. But such an alternative leads to other problems, as it requires more space, parts, and often has difficulty evenly distributing flow between the cyclones.
[0007] Alternatively, co-current flow type cyclones, as shown in FIG. 2 of this disclosure, lead to less pressure loss but generally need a scavenging flow to most effectively remove the dust from the separator. Without a scavenging flow, the separation may decrease by 20% or even more. For applications such as engine inlet gas cleaning, it is common to use the engine exhaust gas to provide the needed scavenging flow. In a stationary application, such as gas cleaning system in a production plant, a powered suction passage with filters is sometimes used in a co-current cyclone. Further, co-current cyclones using guide vanes to generate spiral flow are generally more vulnerable to wear and tear by sand, or clogging due to paper, leaves, or rope in street sweeper applications.
[0008] When dust separators are used in a mobile vacuum equipment application, such as a street sweeper, the separated dust is typically maintained or stored within the equipment, instead of being exhausted into the environment. Using an extra suction source with filtration capability to collect dust, such as is often required in a co-current flow cyclone, is less attractive from both a power and space stand point.
SUMMARY
[0009] The disclosure herein generally relates to an improved apparatus, system and method for the separation and collection of dust particles from a gas stream.
[0010] In a first embodiment, a particulate collector apparatus is provided. The apparatus may include (1) a conduit structure having an inlet passage for conveying a particulate-laden gas stream, the passage having an upstream inlet opening with an internal cross-section of a first diameter and a second downstream diameter which is smaller than the first diameter to thereby form a throat of decreased internal cross-section in the inlet passage, (2) a separator positioned downstream of the throat, where the separator divides the inlet passage into an outlet channel and a particulate-collection channel, where the outlet channel and the particulate collection channel are diverging, (3) a partition extending from the second diameter of the throat, the partition beginning a distance from the second diameter to form a gap in the inlet passage, the partition forming a portion of the particulate-collection channel with the separator, and (4) a particulate-collection chamber positioned downstream of the particulate-collection channel, the particulate-collection chamber defining a space for collection of particulate matter, the chamber in fluid connection with the gap, whereby the particulate-laden gas stream flowing past the gap causes a recirculating gas flow from the chamber.
[0011] In accordance with the above, the first embodiment receives a particulate-laden (e.g. dust-laden) gas stream into an inlet passage and conveys it into a gradually narrowed conduit, so as to increase the velocity of the gas. At the throat of the tunnel is a rapid change in flow direction around a radial surface with relatively small radius. This is accomplished in this embodiment with minimum pressure losses, while separating heavier particles from the main flow path in view of the sudden change in flow direction and preferably also by a properly positioned separator or stream divider, located downstream of the throat. The particulates separated out at this point are collected in a chamber or similar particulate-containment chamber/vessel. This apparatus is considered to achieve over 85% collection efficiency on fine sand, for instance, at a pressure loss as low as a 0.45 inch water column at a flow rate of 70 ft/second.
[0012] An aspect of this embodiment in one form is a secondary flow which can be induced from the dust chamber. To this end, the throat zone has a wall with a gap, which forms a gas recirculation channel connecting to the chamber. As gas (e.g., air) velocity increases at the throat, lower pressure will occur at the gap, according to the Venturi effect. Some gas entering the dust chamber will thereby be pulled out of the chamber from the Venturi slot, generating a small amount of secondary flow. This secondary flow will help to move and keep the dust inside the chamber.
[0013] An advantage and benefit from the foregoing feature is that the dust collector apparatus can be relatively simple, compact, and suitable to apply in many places along a duct system. Exemplary applications inside a mobile cleaning vehicle, for instance, including a fan or blower to force air through the separators, a frame to support the other components and a set of wheels to move the vehicle. In some examples, the dust collector apparatus may be placed near the front of the vehicle, having a hinged door open and close by gravity or actuators to empty the dust along with other debris when tipping the debris body. It may also be placed near one side of the debris body and include a side door to access the collected dust from the side. The dust collector apparatus may also be positioned close to the rear end of the vehicle and use the tailgate of the debris body also as the dust chamber door so that both are discharged at the same time. These are just some examples.
[0014] In another embodiment, a method of separating particulate matter from a gas stream is provided. The method may include the steps of (1) conveying a particulate-laden gas stream through an inlet passage of a conduit structure, the passage having an upstream inlet opening with an internal cross-section of a first diameter and a second downstream diameter which is smaller than the first diameter to thereby form a throat of decreased internal cross-section in the inlet passage, (2) separating particulate matter from the particulate-leaden gas stream at a separator positioned downstream of the throat, where the separator divides the inlet passage into an outlet channel and a particulate-collection channel, where the outlet channel and the particulate-collection channel are diverging, (3) directing the particulate matter with a partition extending from the second diameter of the throat, the partition beginning a distance from the second diameter to form a gap in the inlet passage, the partition forming a portion of the particulate-collection channel with the separator, (4) collecting the particulate matter in a particulate-collection chamber positioned downstream of the particulate-collection channel, the particulate-collection chamber defining a space for collection of particulate matter, the chamber in fluid connection with the gap, and (5) causing a recirculating flow through the gas recirculation channel by way of the particulate-laden gas stream flowing past the gap.
[0015] In another embodiment, an apparatus for separating particulate matter from a gas stream is provided. The apparatus may include (1) a cylindrical body, the cylindrical body having a first cross-sectional diameter, a body top end, and a body bottom end, (2) an inlet passage tangentially entering the cylindrical body adjacent to the top end, and forming a cyclonic separation chamber with the cylindrical body, (3) an outlet passage tangentially exiting the cylindrical body adjacent to the bottom end, (4) a first tube, the first tube having a second cross-sectional diameter smaller than the first body diameter, a first tube upper end, and a first tube lower end, where the lower end of the first tube extends generally coaxially through the top end of the cylindrical body and past the inlet passage and into the cyclonic separation chamber, (5) a second tube, the second tube having a second tube upper end and a second tube lower end, where the upper end of the second tube extends through the bottom end of the cylindrical body into the cyclonic separation chamber and the second tube upper end is in general coaxial alignment with the first tube lower end, where the lower end of the first tube and the upper end of the second tube are separated by a gap, and (6) a particle-collection chamber communicating with the outlet passage, the chamber further having a gas passage channel extending from a chamber outlet to the upper end of the first tube and forming a gas recirculation channel.
[0016] When suction is applied to the lower, open end of the second tube of the foregoing embodiment, particulate-leaden gas (e.g. dust-laden gas) will enter the apparatus through the tangential inlet passage, turn around the cylindrical body and travel toward the other end. The first tube and a top end of the cylindrical body that is helical in shape will preferably funnel the flow smoothly to reduce turbulence and dead zones, minimizing pressure loss. Along the spiral stream, particulates will move towards the cylindrical body outer wall due to centrifugal force. Clean gas remains close to the center, and then exits from the second tube through the opening gap. Meanwhile, the highly dust-concentrated stream will continue to move downward until reaching a bottom end of the cylindrical body that is also helical in shape, and then exit tangentially from the outlet passage to the particle-collection chamber, or dust holder. Because the suction from the second tube can also cause vacuum pressure at the lower end of the first tube, a small amount gas flow will circulate through the dust holder and re-enter the cylindrical body via the gas passage channel and first tube. As a result, this embodiment provides an improved co-current cyclone to separate dust from a high rate gas flow with a self-contained scavenging feature to effectively move and collect dust.
[0017] Another aspect of this embodiment may employ a reverse flow cyclone as the dust holder, such that the cyclone inlet receives the dust concentrated flow from the dust outlet passage of the cylindrical body. The outlet of the reverse flow cyclone is connected to the outside open end of the first inner tube. As only small amount of gas flow will go through the reverse flow cyclone, a very low pressure drop would occur, resulting in better separation through the self-scavenging flow. Using this apparatus to collect PM10 powders, for example, it is considered that the efficiency can be over 98.5% at a pressure loss of only a 3.4 inch of water column at a flow rate of 70 ft/second.
[0018] In another embodiment, a method of separating particulate matter from a gas stream is provided. The method may include the steps of (1) conveying a particulate-leaden gas stream through an inlet passage, the inlet passage tangentially entering a cylindrical body having a first cross-sectional diameter, a body top end, and a body bottom end, where the inlet passage tangentially enters the cylindrical body adjacent to the top end and forms a cyclonic separation chamber with the cylindrical body, the cylindrical body further including (a) a first tube, the first tube having a second cross-sectional diameter smaller than the first body diameter, a first tube upper end, and a first tube lower end, where the lower end of the first tube extends generally coaxially through the top end of the cylindrical body and past the inlet passage and into the cyclonic separation chamber, and (b) a second tube, the second tube having a second tube upper end and a second tube lower end, where the upper end of the second tube extends through the bottom end of the cylindrical body into the cyclonic separation chamber and the second tube upper end is in general coaxial alignment with the first tube lower end, where the lower end of the first tube and the upper end of the second tube are separated by a gap, (2) separating particulate matter from the particulate-leaden gas stream in the cyclonic separation chamber, (3) directing the particulate matter to an outlet passage tangentially exiting the cylindrical body adjacent to the bottom end, (4) collecting the particulate matter in a particle-collection chamber communicating with the outlet passage, the chamber further including a gas passage channel extending from a chamber outlet to the upper end of the first tube and forming a gas recirculation channel, and (5) applying suction to the lower end of the second tube to force the particulate-leaden gas stream into the inlet passage and to cause a recirculating flow through the gas recirculation channel.
[0019] In general, the embodiments described above can achieve high collection efficiency and low pressure drop, yielding an improved apparatus, method and system particularly useful in mobile vacuum equipment. These as well as other aspects, advantages, and alternatives, will become apparent to those of ordinary skill in the art by reference to the following detailed description, taken in conjunction with the drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a typical reverse flow cyclone separator;
[0021] FIG. 2 is a typical co-current flow cyclone separator;
[0022] FIG. 3 is a cross-sectional schematic of an example embodiment suitable for use in an elbow duct arrangement;
[0023] FIG. 4 is another cross-sectional schematic of an example embodiment suitable for use in a substantially straight duct arrangement;
[0024] FIG. 5 is a cross-sectional schematic of another example embodiment;
[0025] FIG. 6 is a perspective schematic of yet another example embodiment;
[0026] FIG. 7 is a perspective schematic of still another example embodiment;
[0027] FIG. 8 is a flowchart depicting an example method according to an example embodiment; and
[0028] FIG. 9 is a flowchart depicting an example method according to another example embodiment.
DETAILED DESCRIPTION
[0029] In the following detailed description, reference is made to the accompanying Figures (Figs) which form a part thereof. In the Figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are contemplated herein.
[0030] Various embodiments of the invention will now be described with reference to the Figures. The following description provides specific details for a thorough understanding and an enabling description of these embodiments. One skilled in the art will understand, however, that the invention may be practiced without many of these details. Additionally, some well-known structures or functions may not be shown or described in detail, so as to avoid unnecessarily obscuring of the relevant description of the various embodiments. The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention.
[0031] Referring now to FIG. 3 , a cross-sectional view of an example dust collector 1 is shown, and will be described below in conjunction with the method of FIG. 8 . The dust collector 1 includes an inlet passage 15 and outlet channel 22 at approximately 90 degrees. Walls 2 and 3 (which shown here form a generally circular channel, with use of elements 2 and 3 merely to help in further orientation for the reader, it being understood that a single sidewall structure of any shape is intended) form a passage gradually narrowing from a first diameter to a second diameter in order to accelerate the dust-laden gas into the throat 4 of the dust collector 1 . The bottom wall 3 then turns substantially 90 degrees with a small radius after the throat 4 , following by another relatively straight wall 7 . A curved partition wall 14 extends substantially from the end of wall 2 at throat zone 4 , but leaving a gap 21 , and then forms a portion of the turn in the inlet passage 22 . The partition wall 14 also forms a portion of a particulate-collection channel 18 along with another wall 8 .
[0032] Wall 8 is placed downstream of the throat 4 , in the turn between walls 7 and 14 to create two diverging channels; the outlet channel 22 and the particulate collection channel 18 . The upper tip 6 of wall 8 operates as the leading edge of a separator for the gas stream. When a dust-laden gas stream is conveyed 101 into the inlet passage 15 , its velocity will gradually increase to the throat 4 . In the elbow shaped chamber 16 of the dogleg, the gas will change direction rapidly, especially with the help of what is referred to as the Coanda effect. However, the heavier particles will not be able to make this turn due to inertial effects. As a result, the heavier dust is separated 102 from the main gas stream at separator tip 6 . While clean gas will move inward at 17 and flow out from outlet channel 22 defined by walls 7 and 8 , the dust will move outward and be directed 103 by partition wall 14 into the particulate-collection chamber 13 enclosed by walls 8 , 9 , and 10 for collecting 104 the particulate matter.
[0033] A cleanout door 11 is illustrated in this embodiment as hinged on the right-hand-side at 12 . It will be understood that it can also be placed at the front, back or bottom sides as needed. Note that, especially as the chamber 13 may not be very large, which is often the case in mobile equipment, separated and collected dust may be difficult to settle in the chamber 13 , and may move back up toward the separator tip 6 to rejoin the gas stream. This invention mitigates this problem by introducing a relatively small recirculating gas flow 19 through the chamber 13 .
[0034] A gas recirculation channel 20 is formed behind the curved partition wall 14 and the chamber wall 10 . Remember that partition wall 14 started after a gap 21 in the inlet upper wall at the throat 4 . As the faster gas steam flows past the gap 21 , lower pressure will be generated according to the Venturi effect. This will cause 105 a recirculating gas flow 19 to be induced out of the chamber 13 , through the gas recirculation channel 20 , and though the gap 21 . In view of the relatively large and vertical nature of the channel 20 , any fine dust sticking to the walls may easily fall into the chamber by shaking the chamber 13 , or simply through the vibration often associated with mobile equipment.
[0035] Because of the turn, short path, and quick time to separate dust, the present example in various embodiments will have less loss due to friction and turbulence. In addition, due to the introduction of the internal recirculation flow, dust can more easily be moved into and retained inside a relatively small collection chamber. These features result in an effective and compact dust separation and collection device. The turn between the inlet passage 15 and the outlet passage 22 need not be exactly 90 degrees, but may vary between, for example, 75 and 95 degrees.
[0036] Another alternative example 1a is presented in FIG. 4 , which is especially suitable for an application where the inlet passage 15 a and outlet channel 22 a are generally in-line. Walls 2 a and 3 a form a channel of decreasing diameter to gradually increase the gas velocity. At the throat 4 a, the upper wall 3 a turns into curved wall 5 a bending upward at an angle preferably between 70 to 90 degrees, followed by a generally smooth transition bending back in line with the inlet passage 15 a, as shown at wall 7 a. Tangentially extending from the lower wall 2 a at throat 4 a, but leaving a gap as presented by 21 a, there is curved partition wall 14 a. This wall is properly shaped to provide a smooth path and to direct the dust to fall into the dust chamber 13 a at one end.
[0037] Between walls 7 a and 14 a there is another curved wall 8 a, which will create two passageways—the upper, outlet channel for the clean gas stream and the lower, particulate-collection channel 18 a for the dirty stream. In the upward turning chamber 16 a, gas will change direction rapidly, again with the help of known Coanda effect, but the heavier particles will have difficulty doing so due to their inertia. The dust is separated from the curved gas stream and diverted from the main gas stream at separator tip 6 a. While clean gas will move upward at 17 a and flow out from outlet channel 22 a defined by walls 7 a and 8 a, the dust will move generally in a straight path, and finally fall into the chamber 13 a enclosed by walls 9 a, 10 a and a cleanout door 11 a.
[0038] In this embodiment, an internal recirculating gas flow 19 a through the chamber 13 a is created by the gap 21 a between the curved partition wall 14 a and wall 2 a at the throat 4 a, according to the Venturi effect. Again, although the cleanout door 11 a is illustrated in the figure of this embodiment as hinged on the left-hand side at 12 a, it is easy to understand it may be used at the right-hand side, front, or back sides as needed.
[0039] Another alternative embodiment 1b of the invention is shown in FIG. 5 . Here, the turn between the inlet passage 15 and outlet channel 22 is greater than 90 degrees. Other similar angles are also possible, for instance, between 95 and 120 degrees. An interesting aspect of this configuration is to use the debris hopper door of a mobile vacuum truck as a cleanout door 11 b of the dust chamber 13 b. Wall 2 b serves as both the wall of inlet 15 b and a part of the dust chamber 13 b. After a gap 21 b, this wall continues with a curved shape in partition wall 14 b to guide the dust into the chamber 13 b and keep it inside. Wall 3 b, along with wall 2 b, provide an inlet passage 15 b of decreasing diameter to gradually accelerate the dust-laden gas. Wall 3 b leads to a radius at 5 b to cause the gas to change direction at 16 b. While gas and fines may quickly follow the path with the help of the Coanda effect, more dense particles may not, and will separate from the gas stream to move along the particle-collection channel 18 b. At the elbow area, separator tip 6 b is where the outlet wall 7 b and dust chamber wall 10 b meet to divide the gas stream into clean and dust-concentrated branches. The clean gas stream proceeds to the outlet channel 22 b formed by walls 7 b and 8 b. In this embodiment, the recirculating flow 19 b through the dust chamber 13 b starts at the Venturi gap 21 b, located at the throat 4 b. Wall 9 b is the bottom portion of the chamber and includes a seal 23 b to engage the rear door 11 b. When the dust collector tilts along with the debris body, the door 11 b will open and discharge the dust along with the other debris.
[0040] To further effectively collect even smaller size particles with low pressure loss, another example dust collector 30 is presented in FIG. 6 . The dust collectors shown in FIGS. 6 and 7 are oriented vertically, and the following description refers to corresponding parts as top and bottom to assist in the reader's understanding of the figures. However, it should be understood that the dust collectors shown in FIGS. 6 and 7 may take any orientation, in whole or in part. For example, the dust collector of FIG. 6 may be oriented substantially horizontally.
[0041] Generally, the example in FIG. 6 consists of a dust separator, a dust collector, and various passageways. The separator consists of a cylindrical body 31 , a first tube 32 having a portion of its length coaxially inserted through the top end 34 of the cylindrical body 31 . The separator also includes a second tube 33 inserted from the bottom end 35 of the cylindrical body 31 and axially aligned with the first tube 31 . The first and second tubes have substantially the same diameter, and the ratio of the diameter of the first and second tubes 32 , 33 to the diameter of the cylindrical body 31 may be between 1.75 and 3.
[0042] A gap 38 separates the lower end of the first tube 32 and the upper end of the second tube 33 , and the gap 38 may have a distance between 0.75 and 2 times the diameter of the first and second tubes. The top end 34 and bottom end 35 of the cylindrical body 31 may be a helical in shape. An inlet passage 36 is tangentially connected to the cylindrical body 31 adjacent to the top end 34 and above the lower end of the first tube 32 , forming a cyclonic separation chamber within the cylindrical body 31 . The distance between the top end 34 and the lower end of the first tube 32 may be 2 and 5 times the diameter of the cylindrical body 31 . Similarly, a dust outlet passage 37 is tangentially connected to the cylindrical body 31 adjacent to the bottom end 35 and below the upper end of the second tube 33 .
[0043] Both inlet passage 36 and dust outlet passage 37 are preferably at a downward inclined angle alpha (as the reader views this Figure) between 15 to 30 degrees to the cylindrical body 31 , to improve separation. A particle-collection chamber 40 generally has an inlet channel 41 connecting to the outlet passage 37 and a chamber outlet 42 connecting to the top end 46 of the first tube 32 via a gas passage channel 47 . The particle-collection chamber 40 may also include a dust holder 49 .
[0044] Use of the dust collector 30 in FIG. 6 can be described in conjunction with the method of FIG. 9 . When suction is applied 205 to the lower end 48 of the second tube 33 , particulate-laden gas 39 will enter the dust collector 30 through the tangential inlet 36 . The gas 39 is conveyed 201 to the cylindrical body 31 , then swivels (or turns) around the cylindrical body 31 and travels toward the bottom end 35 . The first tube 32 and helical end 34 will funnel the flow smoothly to reduce turbulence and dead zones and minimize pressure loss. Along the spiral stream 43 , particulates will be separated 202 from the gas stream and move toward the outer barrel wall due to centrifugal force. Clean (or cleaner) gas remains close to the center, and then exits from the second tube 33 through the opening 44 at gap 38 .
[0045] Meanwhile, the highly dust-concentrated stream 45 will continue to be directed 203 downward until reaching the helical end 35 and exit tangentially to the particle-collection chamber 40 , where it is collected 204 . Because the suction applied 205 to the second tube 33 can also cause vacuum pressure at the lower end of the first tube 32 , a small amount gas flow 50 will circulate through the particle-collection chamber 40 and re-enter the cylindrical body 31 via the gas passage channel 47 and first tube 32 . Thus, it will provide a self-contained scavenging flow to move the dust out of the separation zone. This improved dust separation and collection apparatus provides low pressure loss and high efficiency.
[0046] A further embodiment 30 a is presented in FIG. 7 , in which the particle-collection chamber 40 a uses a reverse flow cyclone, such that the scavenging flow 45 a will result in further dust separation and collection. The cyclone inlet 41 a receives dust concentrated flow 45 a from the outlet passage 45 a of the cylindrical body 31 . The cyclone outlet 42 a is connected to the top end 46 a of the first tube 32 a via a gas passage channel 47 a. As only a small amount of flow will go through the reverse flow cyclone 40 a, there will be a generally very low pressure drop that will occur, and better separation thereby results through the self-scavenging flow achieved. For a PM10 dust mixed air flow at rate of 70 ft/second, this device is considered to be able to achieve over 98.5% collection efficiency at a pressure loss only a 3.4 inch water column. In comparison, an equivalently sized typical reverse flow cyclone would cause a 13.4 inch water column pressure loss.
[0047] As noted above, each of the example dust collectors shown in FIGS. 3-7 may be included in a mobile vacuum vehicle. Such a vehicle may include a fan or blower to generate the vacuum source need to force a dust-laden gas stream into the dust collector's inlet passage 15 . The vehicle may also include a cabin for a driver to control the vehicle, or it may be remotely or autonomously operated. Finally, the vehicle may include a frame to support the other components, and a set of wheels to move the vehicle.
[0048] Although the invention has been shown and described with respect to preferred embodiments thereof, it should be understood by those skilled in the art that various changes and omissions in the form and detail thereof may be made therein without departing from the spirit and the scope of the invention.
[0049] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.
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Highly efficient particulate collectors, such as for dust and street debris collected by a mobile street cleaning vehicle, with very low pressure loss are disclosed. One embodiment uses a specially contoured passage to separate the solid particles from particulate-laden gas stream by rapid directional change at a throat region. By using the Venturi effect at the accelerating zone communicating with a gas return channel from the particulate retaining chamber, a small amount of the gas will be recirculated from the deposit zone to help move and retain the separated particles in a confined collection receptacle.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a process for the preparation of structural composites from fiber reinforced prepregs, where consolidation of the prepregs into a multi-layer composite is facilitated by a consolidation liner having a high parting force, which preferably contains no controlled release additives.
[0003] 2. Description of the Related Art
[0004] Fiber reinforced composite structures prepared from fiber reinforced prepregs have been important in many industrial sectors, particularly in the aerospace industry. In commercial aircraft, for example, fiber reinforced composites are increasingly being used for non-critical sections of aircraft. However, in military aircraft such as attack helicopters, jet fighters and bombers (including stealth versions), fiber reinforced composites, particularly those using carbon fiber reinforcement, are used in critical components such as stressed body panels, wings, tail sections, ailerons, etc. Prepregs have also been used to manufacture blades of helicopters, and wind turbines as well.
[0005] Such products are generally prepared in quasi-isotropic layups, where “prepregs” containing a high strength thermoplastic polymer resin such as a polyetherketone, polyether sulfone, polyimide, or their variants, or a B-staged curable thermosetting resin such as epoxy, bismaleimide, cyanate, or crosslinkable polyimide, and also containing generally unidirectional fibers are used. Fibers may, for example, be glass fibers, carbon fibers, UHMWPE fibers, aramid fibers and the like. Prepregs may also be based on woven of non-woven cloth of such fibers, or combinations of these. The prepregs are “laid up” with the desired fiber orientations and number of plies.
[0006] Once the desired, unconsolidated prepreg “lay-up” has been assembled, it must then be consolidated. Consolidation takes place at high temperature and generally under high pressure, the temperature used depending principally upon the curing profile of the thermoset resin, when such resins are used, or the melt temperature and melt flow rate when thermoplastic resins are used. The pressure must be high enough to guarantee complete contact between the many layers, and to eliminate voids. Some composite lay-ups are evacuated prior to cure, to eliminate the risk of trapping air bubbles, and then introduced into a high pressure autoclave, or a press or mold. Many parts are encased in “vacuum bags” for this purpose. In the present invention, high pressure is a pressure higher than 0.25 kPa, more preferably higher than 0.5 kPa, and most preferably about 1 kPa to 15 kPa.
[0007] During cure, it is often necessary that a consolidation liner be adhered to the uncured lay-up, to prevent the structure from becoming bonded to the autoclave, or to the mold in which it is cured. The consolidation liner may also aid in retaining resin whose viscosity has been lowered as the temperature is increased to the consolidation temperature, but is still of low enough viscosity to flow or drip. Finally, the consolidation liner may add in development of a smooth and, where necessary, a textured or aesthetic surface. Release papers may be used to provide stiffness and handleability to the uncured prepregs during the laying up of the uncured composite structure. These release papers have characteristics quite different from consolidation liners.
[0008] Silicone coated release papers have long been used in many fields where release from tacky substances is needed. Such papers offer low release force and may be useful in lining the prepregs prior to lay-up, during lay-up, and for improved shipping and handling characteristics. However, while prepregs such as thermoset resin prepregs can be quite tacky, the consolidated structure is not tacky at all, and release papers may separate prematurely from the consolidated composite. Solvent and emulsion tin condensation-curing systems, and solvent free and organic solvent-borne addition curing systems can achieve a high enough release level to satisfy many composites applications. Each of these systems also exhibit noted disadvantages, including in some cases, slow rates of cure, and in others, the use of organic solvents, which is highly disfavored. Furthermore, yet higher parting force than can be provided by such systems is often desirable.
[0009] It would be desirable to provide a process for structural composite manufacture where a consolidation liner is used, whose parting surface can be prepared economically and substantially solvent free, has a high cure rate, and which has a high parting force even on cured parts. Addition curable organopolysiloxane coatings would appear to be good candidates, as they exhibit high rates of cure, and can be coated without the use of appreciable amounts of solvent, or of any solvent. However, their parting force is too low. In the past, “controlled release additives” have been added to addition curable and other silicone release coatings to increase parting force. However, the increase in parting force is often not high enough. It would further be desirable to employ a consolidation liner or release paper in prepreg and composite applications where the release force can be widely adjusted, and which can exhibit higher release force than silicone compositions employing controlled release additives.
SUMMARY
[0010] It has now been surprisingly and unexpectedly discovered that in the consolidation of composite structures by lay-up of fiber reinforced prepregs and subsequent cure into a consolidated, fiber-reinforced composite structure, satisfactorily high and consistent parting force of a consolidation liner is achieved by a substrate, e.g. paper, coated with a combination of an aqueous emulsion of a vinyl addition polymer, an ethylenically unsaturated organopolysiloxane, an Si—H functional silane or polysiloxane, and a hydrosilylation catalyst. The presence of a controlled release additive is not necessary, and not preferred. The compositions are preferably free of controlled release additives.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The fiber reinforced prepregs useful in the present invention include all those prepregs having fiber reinforcement and a curable thermoset and/or fusible thermoplastic matrix. Such prepregs are well known and are now staple items of commerce. The fibers may be continuous or discontinuous, and may be in the form of individual fibers, multi-fiber strands of fibers, tow, yarn, woven or non-woven fabric or the like.
[0012] Suitable thermosetting resins include, for example, but not by limitation, epoxy resins, cyanate reins, bismaleimide resins, and crosslinkable polyimide resins. These resins may also contain particulate thermoplastics to improve delamination strength. The resins are generally B-staged in the prepregs. Suitable thermoplastic resins include polyamides, polycarbonates, polyarylsulfides, polyarylsulfones, polyether sulfones, polyether ketones (“PEK”) and their analogues such as PEKK, PEKEK, etc. All these are well known in the art.
[0013] The consolidation liner used in the inventive process comprises a substrate coated with a parting coating. Paper, for example, Kraft process paper, preferably calendered, is preferred, but other commonly used substrates such as polymer films, paper/polymer film laminates, metal foils, woven and non-woven scrim, and combinations thereof may also be used. The consolidation liner does not constitute part of the finished composite structure, but is parted therefrom following cure. In this application, “cure” implies a final consolidation, e.g. crosslinking of a thermoset resin, particularly a B-staged thermoset resin to a fully crosslinked state, as well as consolidation of thermoplastic matrix prepregs by fusion of the polymer, where no or little crosslinking takes place.
[0014] The parting composition is an aqueous, curable composition containing from 0.5 to 80 weight percent, preferably 3 to 30 weight percent, and most preferably 4 to 12 weight percent, all weight percents based on solids, of an emulsion or suspension polymerized addition polymer (A), in the form of an aqueous dispersion; a polyorganosiloxane (B) bearing at least two ethylenically unsaturated Si—C bonded hydrocarbon groups; an Si—H functional silane or siloxane (C) bearing at least three silicon-bonded hydrogen atoms; and a hydrosilylation catalyst (D). More than one of each type of component may be used.
[0015] The suspension or preferably emulsion polymerized addition polymer or copolymer (A) may have a wide range of molecular weights and Tg. The Tg may be, for example, from −75° C. to +100° C. The polymers are prepared by suspension or emulsion polymerization of an aqueous dispersion of vinyl monomers, with gaseous monomers such as ethylene, propylene, or 1,3-butadiene, for example, being supplied under pressure. One or more emulsifiers are added to keep the vinyl monomers and growing polymers in the form of an emulsion and/or dispersion. The polymerization temperature is generally from 40 to 100° C., preferably from 60 to 80° C. In the case of the copolymerization of gaseous comonomers, operation may be carried out at superatmospheric pressure, generally at from 5 to 100 bar. Such polymer dispersions are well established items of commerce.
[0016] The emulsion polymerized addition polymers are preferably based on homo- or copolymers of one or more monomers from the group of vinyl esters of unbranched or branched alkyl carboxylic acids having from 1 to 15 carbon atoms, methacrylic esters and acrylic esters of alcohols having from 1 to 15 carbon atoms, vinylaromatics, olefins, dienes, and vinyl halides.
[0017] Vinyl esters suitable for the base polymer are those of carboxylic acids having from 1 to 15 carbon atoms. Preferred vinyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl-2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate and vinyl esters of α-branched monocarboxylic acids having from 9 to 13 carbon atoms, examples being VeoVa9® or VeoVa10®, available from Momentive. Vinyl acetate is particularly preferred.
[0018] Suitable methacrylic esters or acrylic esters (“(meth)acrylic esters”) are esters of unbranched or branched (“optionally branched”) alcohols having from 1 to 15 carbon atoms, examples being methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, and norbornyl acrylate. Preference is given to methyl acrylate, methyl methacrylate, n-butyl acrylate and 2-ethylhexyl acrylate.
[0019] Examples of olefins and dienes are ethylene, propylene and 1,3-butadiene. Suitable vinylaromatics are styrene and vinyltoluene. A suitable vinyl halide is vinyl chloride.
[0020] Where appropriate, from 0.05 to 50% by weight, preferably from 1 to 10% by weight, based on the total weight of the base polymer, of auxiliary monomers may also be copolymerized. Examples of auxiliary monomers are ethylenically unsaturated mono- and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid, and maleic acid; ethylenically unsaturated carboxamides and carbonitriles, preferably acrylamide and acrylonitrile; mono- and diesters of fumaric acid and maleic acid, for example the diethyl and diisopropyl esters; and also maleic anhydride, and ethylenically unsaturated sulfonic acids and their salts, preferably vinyl sulfonic acid and 2-acrylamido-2-methyl-propanesulfonic acid. Other examples are pre-crosslinking comonomers, for example ethylenically polyunsaturated comonomers such as divinyl adipate, diallyl maleate, allyl methacrylate, or triallyl cyanurate, or post-crosslinking comonomers, such as acrylamidoglycolic acid (AGA), methyl methacrylamidoglycolate (MAGME), N-methylol acrylamide (NMA), N-methylolmethacrylamide (NMMA), allyl N-methylol carbamate, alkyl ethers or esters of N-methylolacrylamide, of N-methylolmethacrylamide, or of allyl N-methylolcarbamate, such as their isobutoxy ethers. Epoxy-functional comonomers, such as glycidyl methacrylate and glycidyl acrylate, are also suitable.
[0021] Other examples are silicon-functional comonomers, such as acryloxypropyltri(alkoxy)- and methacryloxypropyltri(alkoxy)silanes, vinyl trialkoxysilanes, and vinyl methyldialkoxysilanes, examples of alkoxy groups which may be present being methoxy, ethoxy, and ethoxypropylene glycol ether radicals. Use of silicon-functional comonomers is not preferred. Mention may also be made of monomers having hydroxy or CO groups, e.g. hydroxyalkyl esters of methacrylic acid or of acrylic acid, e.g. hydroxyethyl, hydroxypropyl, or hydroxybutyl acrylate or methacrylate, and also of compounds such as diacetoneacrylamide and acetylacetoxyethyl acrylate or methacrylate.
[0022] Examples of suitable homo- and copolymers are vinyl acetate homopolymers; copolymers of vinyl acetate with ethylene; copolymers of vinyl acetate with ethylene and with one or more other vinyl esters; copolymers of vinyl acetate with ethylene and acrylic esters, copolymers of vinyl acetate with ethylene and vinyl chloride; styrene-acrylic ester copolymers; and styrene-1,3-butadiene copolymers.
[0023] Preference is given to vinyl acetate homopolymers; copolymers of vinyl acetate with from 1 to 40% by weight of ethylene; copolymers of vinyl acetate with from 1 to 40% by weight of ethylene and from 1 to 50% by weight of one or more other comonomers from the group of vinyl esters having from 1 to 12 carbon atoms in the carboxylic acid radical, e.g. vinyl propionate, vinyl laurate, vinyl esters of alpha-branched carboxylic acids having from 9 to 13 carbon atoms such as VeoVa9, VeoVa10, and VeoVa11; copolymers of vinyl acetate, from 1 to 40% by weight of ethylene, and preferably from 1 to 60% by weight of acrylic ester(s) of unbranched or branched alcohols having from 1 to 15 carbon atoms, in particular N-butyl acrylate or 2-ethylhexyl acrylate; and copolymers using from 30 to 75% by weight of vinyl acetate, from 1 to 30% by weight of vinyl laurate or vinyl esters of an alpha-branched carboxylic acid having from 9 to 11 carbon atoms, and also from 1 to 30% by weight of acrylic esters of unbranched or branched alcohols having from 1 to 15 carbon atoms, in particular n-butyl acrylate or 2-ethyl hexyl acrylate, where these also contain from 1 to 40% by weight of ethylene; and copolymers using vinyl acetate, from 1 to 40% by weight of ethylene, and from 1 to 60% by weight of vinyl chloride; where the polymers may also contain the amounts mentioned of the auxiliary monomers mentioned, the percentage by weight in each case totaling 100% by weight. A preferred ethylene/vinyl acetate polymer is VINNAPAS® 315, available from Wacker Chemie AG, Munich, Germany.
[0024] Preference is also given to copolymers of n-butyl acrylate or 2-ethylhexyl acrylate, or copolymers of methyl methacrylate with n-butyl acrylate and/or 2-ethylhexyl acrylate; styrene-acrylic ester copolymers using one or more monomers from among methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate; vinyl acetate-acrylic ester copolymers using one or more monomers from the group of methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and, where appropriate, ethylene; and styrene-1,3-butadiene copolymers; where the polymers may also contain auxiliary monomers, and the percentages by weight totals 100%.
[0025] The selection of monomer or the selection of the parts by weight of the comonomers is preferably such that the resultant glass transition temperature Tg is from −75° C. to 100° C., more preferably from −30° C. to +40° C. The glass transition temperature Tg of the polymers may be determined in a known manner by differential scanning calorimetry (DSC). The Fox equation may also be used for an approximate preliminary calculation of Tg. According to T. G. Fox, BULL. AM. PHYSICS SOC. 1, 3, page 123 (1956): 1/Tg=x 1 /Tg 1 +x 2 /Tg 2 + . . . +x n /Tg n , where x n is the fraction by weight (% by weight/100) of the monomer n, and Tg n is the glass transition temperature in Kelvin of the homopolymer of the monomer n. Tg values for homopolymers are listed in POLYMER HANDBOOK 2nd Edition, J. Wiley & Sons, New York (1975).
[0026] The polymerization is initiated using water-soluble or monomer-soluble initiators or redox-initiator combinations, these being those commonly used for emulsion polymerization and suspension polymerization, respectively. Examples of water-soluble initiators are the sodium, potassium, and ammonium salts of peroxydisulfuric acid, hydrogen peroxide, tert-butyl peroxide, tert-butyl hydroperoxide, potassium peroxydiphosphate, tert-butyl peroxypivalate, cumene hydroperoxide, isopropylbenzene monohydroperoxide, and azobisisobutyronitrile. Examples of monomer-soluble initiators are dicetyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, and dibenzoyl peroxide. The amount of the initiators generally used is from 0.01 to 0.5% by weight, based on the total weight of the monomers.
[0027] Redox initiators include combinations of the initiators previously mentioned with reducing agents. Suitable reducing agents are the sulfites and bisulfites of the alkali metals and of ammonium, for example sodium sulfite, the derivatives of sulfoxylic acid, for example zinc formaldehyde sulfoxylates or alkali metal formaldehyde sulfoxylates, an example being sodium hydroxymethanesulfinate, and ascorbic acid. The amount of reducing agent is preferably from 0.01 to 0.5% by weight, based on the total weight of the monomers.
[0028] To control molecular weight, molecular weight regulating substances (chain transfer agents) may be used during the polymerization process. If regulators are used, the amounts are generally from 0.01 to 5.0% by weight, based on the weight of the monomers to be polymerized, and the regulators may be fed separately and/or after premixing with other components for the reaction. Examples of these substances are n-dodecyl mercaptan, tert-dodecyl mercaptan, mercaptopropionic acid, methyl mercaptopropionate, isopropanol, and acetaldehyde. It is preferable not to use any regulating substances.
[0029] The polymerization may take place in the presence of fully or partially hydrolyzed polyvinylalcohol polymers (fully or partially hydrolyzed polyvinyl acetate) or hydrolyzed polyvinylalcohol/ethylene copolymers. When the latter are used, these are preferably protective colloids, with an ethylene content of from 1 to 15 mol %, with a degree of hydrolysis of the vinyl acetate units of 80 mol % to about 95 mol %, and with a Hoppler viscosity, in 4% strength aqueous solution, of from 2 to 30 mPas (Hoppler method at 2020 C., DIN 53015). In preferred embodiments, the Hoppler viscosity is from 3 to 25 mPas, and the degree of hydrolysis is from 85 to 90 mol %. The ethylene content is preferably from 1 to 5 mol %. The protective colloid content in dispersions and powders is in each case from 3 to 30% by weight, preferably from 5 to 20% by weight, based in each case on the base polymer. The protective colloids used are generally water-soluble. Lesser amounts of protective colloid are generally necessary when the addition polymer is not isolated, and is used in the process of the invention as an aqueous dispersion, as produced.
[0030] The protective colloids may be prepared by known processes for polyvinyl alcohol preparation. The polymerization process is preferably carried out in organic solvents at an elevated temperature, using peroxides as a polymerization initiator. Solvents used are preferably alcohols such as methanol or propanol. The ethylene content of the polymer may be controlled by means of the ethylene pressure. The resultant vinyl acetate-ethylene copolymer is preferably not isolated, but directly subjected to hydrolysis. The hydrolysis may take place by known processes, for example by using methanolic NaOH catalysis. After the hydrolysis, the solvent is replaced by water through work-up by distillation. The protective colloid is preferably not isolated but used directly in the form of an aqueous solution for the polymerization process.
[0031] Suitable emulsifiers include anionic, cationic, and non-ionic emulsifiers, for example anionic surfactants such as alkyl sulfates whose chain length is from 8 to 18 carbon atoms, or alkyl or alkyl aryl ether sulfates having from 8 to 18 carbon atoms in the hydrophobic radical and up to 40 ethylene or propylene oxide units, alkyl- or alkylarylsulfonates having from 8 to 18 carbon atoms, esters and half esters of sulfosuccinic acid with monohydric alcohols or with alkylphenols, or non-ionic surfactants such as alkyl polyglycol ethers or alkylarylpolyglycol ethers having from 8 to 40 ethylene oxide units. All of the monomers may form an initial charge, or all of the monomers may form a feed, or portions of the monomers may form an initial charge and the remainder may form a feed after the polymerization has been initiated. The procedure is preferably that from 50 to 100% by weight, based on the total weight of the monomers, form an initial charge and the remainder forms a feed. The feeds may be separate (spatially and chronologically), or all or some of the components to be fed may be fed after preemulsification.
[0032] All or a portion of the auxiliary monomers may likewise form an initial charge or form a feed, depending on their chemical nature. In the case of vinyl acetate polymerization processes, the auxiliary monomers may form a feed or may form an initial charge, depending on their copolymerization parameters. For example, acrylic acid derivatives may form a feed, whereas vinyl sulfonate may form an initial charge.
[0033] Monomer conversion is controlled by the addition of initiator. It is preferable for all of the initiators to form a feed.
[0034] Once the polymerization process has ended, post-polymerization may be carried out using known methods to remove residual monomer, one example of a suitable method being post-polymerization initiated by a redox catalyst. Volatile residual monomers may also be removed by distillation, preferably at subatmospheric pressure, and, where appropriate, by passing inert entraining gases, such as air, nitrogen, or water vapor, through or over the material.
[0035] Organopolysiloxanes bearing at least two ethylenically unsaturated groups (B) are well known, are commercially available, and preferably correspond to the formula (I):
[0000]
[0036] in which
[0037] R is a monovalent, SiC-bonded, optionally substituted C 1-18 hydrocarbon radical free of aliphatic carbon-carbon double bonds,
[0038] R′ is a monovalent, SiC-bonded, optionally substituted C 1-18 hydrocarbon radical containing at least one aliphatic carbon-carbon double bond, or R
[0039] m is an integer from 40 to 1000,
[0040] n is an integer from 0 to 10 and
[0041] m+n is an integer from 40 to 1000,
[0042] with the provision that the organopolysiloxane contains at least two R′ which are not R.
[0043] The organopolysiloxanes (B) bearing aliphatically unsaturated hydrocarbon groups may also be branched. Examples of branched organopolysiloxanes are those of the general formula
[0000]
[0000] where R and R′ are as defined above,
o is 41 to 1000, preferably 80 to 500, more preferably 100 to 200, and
p is 1 to 6, more preferably 2 to 4, and at least two R′ are not R. Branched organopolysiloxanes having “p” units which are themselves polydiorganosiloxy groups are also quite useful. Many such branched organopolysiloxanes may have 2-6, preferably 3 or 4 polydiorganosiloxane groups of comparable size, e.g. in a star or comb-type arrangement. Such organopolysiloxanes may thus have the formula (IIa)
[0000]
[0000] where m, n, and p have the meanings given above, and X is silicon, or an organopolysiloxane, organic polymer, or other organic radical having a valence of p.
[0044] For the purposes of this invention formulae (II) and (IIa) should be understood such that n units, m units, o units, and p units may be distributed in any way in the organopolysiloxane molecule, for example blockwise or randomly.
[0045] Examples of radicals R are alkyl radicals such as the methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, and tert-pentyl radicals, hexyl radicals such as the n-hexyl radical, heptyl radicals such as the n-heptyl radical, octyl radicals such as the n-octyl radical and isooctyl radicals such as the 2,2,4-trimethylpentyl radical, nonyl radicals such as the n-nonyl radical, decyl radicals such as the n-decyl radical, dodecyl radicals such as the n-dodecyl radical, and octadecyl radicals such as the n-octadecyl radical; cycloalkyl radicals such as the cyclopentyl, cyclohexyl, cycloheptyl and methylcyclohexyl radicals; aryl radicals such as the phenyl, naphthyl, anthryl and phenanthryl radicals; alkaryl radicals, such as the o-, m- and p-tolyl radicals, xylyl radicals, and ethylphenyl radicals; and aralkyl radicals such as the benzyl radical, and the α- and the β-phenylethyl radicals.
[0046] Examples of substituted radicals R are haloalkyl radicals such as the 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2′,2′,2′-hexafluoroisopropyl radical, and the heptafluoroisopropyl radical, and haloaryl radicals such as the o-, m- and p-chlorophenyl radicals.
[0047] Preferably the radical R is a monovalent hydrocarbon radical having 1 to 6 carbon atoms, the methyl radical being particularly preferred. Examples of radicals R′ are alkenyl radicals such as the vinyl, 5-hexenyl, cyclohexenyl, 1-propenyl, allyl, 3-butenyl and 4-pentenyl radicals. Preferably the radical R′ comprises alkenyl radicals, the vinyl radical being particularly preferred.
[0048] The viscosity of the organopolysiloxanes (B) is not critical, and may, for example range from 10 mPa·s or lower to 1·10 6 mPas or higher, since the organopolysiloxanes are present in emulsified form. High viscosity organopolysiloxanes may, however, prove more difficult to emulsify. The organopolysiloxanes (B) preferably possess an average viscosity of 100 to 50,000 mPa·s at 25° C., more preferably 200 to 40,000 mPa·s at 25° C.
[0049] The organopolysiloxanes (B) of the invention may be prepared by customary methods, for example, by of H-siloxane equilibration with the corresponding silanes. Examples of organopolysiloxanes (B) of the invention are organopolysiloxanes containing vinyl groups, of the formula
[0000]
[0050] where Me is a methyl radical and o and p are as defined above.
[0051] In similar fashion, the crosslinker (C) can take varied forms, and Si—H functional crosslinkers are widely available. The Si—H functional crosslinkers are preferably linear, cyclic or branched organopolysiloxanes comprising units of the formula III
[0000]
R
e
2
H
f
SiO
4
-
e
-
f
2
(
III
)
[0052] where
[0053] R 2 is a monovalent, SiC-bonded, unsubstituted or substituted (“optionally substituted”) hydrocarbon radical having 1 to 18 carbon atoms which is free from aliphatic carbon-carbon double bonds,
[0054] e is 0, 1, 2 or 3,
[0055] f is 0, 1 or 2,
[0056] and the sum of e+f is 0, 1, 2 or 3,
[0057] with the proviso that on average there are at least 2 Si-bonded hydrogen atoms. Examples of hydrocarbon radicals R 2 are the same as for hydrocarbon radicals R. The organosilicon compounds (C) preferably contain at least 3 Si-bonded hydrogen atoms.
[0058] Organopolysiloxanes which are more preferably used as organosilicon compounds (C) are those of the general formula
[0000] H h R 2 3-h SiO(SiR 2 2 O) q (SiR 2 HO) r SiR 2 3-h H h (IV)
[0059] where R 2 is as defined above,
[0060] h is 0, 1 or 2,
[0061] q is 0 or an integer from 1 to 1500, and
[0062] r is 0 or an integer from 1 to 200,
[0063] with the proviso that there are on average at least 2 Si-bonded hydrogen atoms, and preferably 3 or more Si-bonded hydrogen atoms. For the purposes of this invention formula IV is to be understood such that q units —(SiR 2 2 O)— and r units —(SiR 2 HO)— may be distributed in any way in the organopolysiloxane molecule.
[0064] Examples of such organopolysiloxanes are, in particular, copolymers of dimethylhydrosiloxane, methylhydrosiloxane, dimethylsiloxane, and trimethylsiloxane units; copolymers of trimethylsiloxane, dimethylhydrosiloxane, and methylhydrosiloxane units; copolymers of trimethylsiloxane, dimethylsiloxane, and methylhydrosiloxane units; copolymers of methylhydrosiloxane and trimethylsiloxane units; copolymers of methylhydrosiloxane, diphenylsiloxane, and trimethylsiloxane units; copolymers of methylhydrosiloxane, dimethylhydrosiloxane, and diphenylsiloxane units; copolymers of methylhydrosiloxane, phenylmethylsiloxane, trimethylsiloxane and/or dimethylhydrosiloxane units; copolymers of methylhydrosiloxane, dimethylsiloxane, diphenylsiloxane, trimethylsiloxane and/or dimethylhydrosiloxane units; and copolymers of dimethylhydrosiloxane, trimethylsiloxane, phenylhydrosiloxane, dimethylsiloxane and/or phenylmethylsiloxane units.
[0065] The organopolysiloxanes (C) preferably have an average viscosity of 10 to 1000 mPa·s at 25° C., and are preferably used in amounts of 0.5 to 8.0, more preferably 1.0 to 5.0 gram atoms of Si-bonded hydrogen per mole of hydrocarbon radical R′ having a terminal aliphatic carbon-carbon double bond in the organopolysiloxane (B). Amounts as high or higher than 20 gram atoms of Si-bonded hydrogen per mole of unsaturated hydrocarbon groups can also be used, but are not preferred.
[0066] The crosslinking catalyst (D) can be any catalyst useful for addition crosslinking through a hydrosilylation reaction. Preferred catalysts are metals, and metal compounds and/or complexes, where the metal is a metal from the platinum group. Examples of such catalysts are metallic and finely divided platinum, which may be on supports such as silica, alumina or activated carbon, compounds or complexes of platinum such as platinum halides, e.g., PtCl 4 , H 2 PtCl 6 .6H 2 O, Na 2 PtCl 4 .4H 2 O, platinum-olefin complexes, platinum-alcohol complexes, platinum-alkoxide complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including reaction products of H 2 PtCl 6 .6H 2 O and cyclohexanone, platinum-vinylsiloxane complexes, such as platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complexes with or without detectable inorganically bonded halogen, bis(gamma-picoline)platinum dichloride, trimethylenedipyridineplatinum dichloride, dicyclopentadieneplatinum dichloride, dimethyl sulfoxide-ethyleneplatinum(II) dichloride, cyclooctadieneplatinum dichloride, norbornadieneplatinum dichloride, gamma-picolineplatinum dichloride, cyclopentadieneplatinum dichloride, and reaction products of platinum tetrachloride with olefin and primary amine or secondary amine or primary and secondary amine, such as the reaction product of platinum tetrachloride in solution in 1-octene with sec-butylamine, or ammonium-platinum complexes. The platinum catalysts may be thermally activatable, or photoactivatable.
[0067] The catalysts (D) are preferably used in amounts of 10 to 1000 ppm by weight (parts by weight per million parts by weight), more preferably 50 to 200 ppm by weight, calculated in each case as elemental platinum metal and based on the total weight of the organosilicon compounds (A) and (B).
[0068] The crosslinkable compositions may further comprise agents which retard the addition of Si-bonded hydrogen to aliphatic multiple bond at room temperature, commonly known as inhibitors (E). As inhibitors (E) it is possible, in the crosslinkable silicone coating compositions, to use any inhibitor which achieves the desired purpose. Examples of inhibitors (E) are 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, benzotriazole, dialkylformamides, alkylthioureas, methyl ethyl ketoxime, organic or organosilicon compounds having a boiling point of at least 25° C. at 1012 mbar (abs.) and at least one aliphatic triple bond, such as 1-ethynylcyclohexan-1-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, 2,5-dimethyl-3-hexyne-2,5-diol, and 3,5-dimethyl-1-hexyn-3-ol, 3,7-dimethyloct-1-yn-6-en-3-ol, a mixture of diallyl maleate and vinyl acetate, maleic monoesters, and inhibitors such as the compound of the formula
[0000] HC≡C—C(CH 3 )(OH)—CH 2 —CH 2 —CH═C(CH 3 ) 2 ,
[0000] available commercially under the trade name “Dehydrolinalool” from BASF SE.
[0069] Where inhibitor (E) is included, it is preferably used in amounts of 0.01% to 10% by weight, more preferably 0.01% to 3% by weight, based on the total weight of the organosilicon compounds (B) and (C). Mixtures of inhibitors may also be used.
[0070] Examples of further constituents which may be used in the release coating compositions are organic solvents, dyes, and pigments. These examples are illustrative and non-limiting, and other constituents may be used if desired. Inorganic fillers of silica, alumina, titania, and other inorganic compounds may also be present, but are not preferred.
[0071] The compositions are preferably free of controlled release additives. Examples of such additives are the CRA® controlled release additives from Wacker Chemie AG, Munich, Germany, such as CRA® 17 and CRA® 42. Controlled release additives for use in curable organopolysiloxane compositions are silicone resins. As is well known, silicone resins are highly crosslinked, network-like polymers, generally solid, having a high proportion of branching siloxy units, i.e. T units RSiO 3/2 and Q units SiO 4/2 .
[0072] Examples of controlled release agents from which the compositions of the invention are preferably free, are silicone resins comprising units of the formula
[0000] R 3 R 2 2 SiO 1/2 and SiO 2 ,
[0000] commonly known as MQ resins, where R 3 is a hydrogen atom, a hydrocarbon radical R 2 , such as the methyl radical, or an alkenyl radical R′, such as the vinyl radical, and the units of the formula R 3 R 2 2 SiO 1/2 may be identical or different. The ratio of units of the formula R 3 R 2 2 SiO 1/2 to units of the formula SiO 2 is preferably 0.6 to 2. It would not depart from the spirit of the invention to add a most minor amount of a controlled release additive, for example less than 10% by weight relative to the sum of the weights of (B) and (C), preferably less than 5%, and most preferably less than 2%. The release coatings are preferably essentially free of controlled release additives, e.g. any controlled release additive present does not increase release force at 15 mm/min by more than 5% relative to a release coating not containing any controlled release additive.
[0073] Examples of organic solvents include petroleum spirits, e.g., alkane mixtures having a boiling range of 70° C. to 180° C., n-heptane, benzene, toluene and xylene(s), halogenated alkanes having 1 to 6 carbon atoms such as methylene chloride, trichloroethylene, and perchloroethylene, ethers, such as di-n-butyl ether, esters such as ethyl acetate, and ketones, such as methyl ethyl ketone and cyclohexanone. Where organic solvents are included they are preferably used in amounts of 5% to 50% by weight, more preferably 5% to 30% by weight, based on the total weight of the organosilicon compounds (A) and (B). Organic solvents are preferably absent, or are present in amounts of less than 20 weight percent relative to the total weight of the aqueous coating composition, preferably, with increasing order of preference, less than 15%, 10%, 5%, and 2% by weight.
[0074] The amount of addition curable silicone components (B) and (C) is with increasing preference, at least 2, 3, 4, or 5 weight percent, and at most 10, 15, 20, 25, 30, 35, 40, 45, or 50 weight percent, these weight percentages based on the total weights of (A), (B), and (C), expressed as solids. The consolidation liners exhibit a high parting force from cured composite structures. When tested by conventional methods, such as FINAT test methods 3 at a release speed of 30 mm/min, the consolidation liners preferably exhibit a release force greater than 325 g/25 mm, more preferably >350 g/25 mm, yet more preferably >450 g/25 mm, and most preferably >500 g/25 mm.
[0075] The compositions may include any ingredient or combination of ingredients listed as optional, i.e. which are not required ingredients, or may be free of such ingredients.
EXAMPLES
Example 1
[0076] Emulsions are prepared by admixing an aqueous vinyl addition polymer emulsion, ethylenically unsaturated organopolysiloxane, and Si—H crosslinking agent, as follows. The polyvinyl alcohol-stabilized ethylene/vinyl acetate copolymer emulsion is available from Wacker Chemie AG as VINNAPAS® 315, containing about 55% polymer, having a predominant particle size of 1.2-1.8 μm, and a viscosity of 1800-2700 mPas. The copolymer has a glass transition temperature of about 17° C.
[0077] The silicone components are DEHESIVE® EM 480, available from Wacker Chemie AG, an aqueous, linear vinyl polymer emulsion with about 50% solids also containing a platinum catalyst, and Wacker® crosslinker V72, an Si—H functional organopolysiloxane crosslinker containing about 30 Si—H bonded hydrogen atoms per molecule on average. These are mixed in the final emulsion according to the manufactures' recommendation, about 100 parts by weight of DEHESIVE EM 480 to about 8 parts by weight of crosslinker V72.
[0078] Preferably, addition polymer emulsion is first blended with the alkenyl-functional silicone to form a uniform dispersion, and then the crosslinker is added and blended to uniformity. The catalyst is usually added last, which is highly preferred, though in practice, the emulsions are very forgiving, and thus any addition order is satisfactory.
[0079] Following blending the emulsions, the emulsions are diluted with water, preferably with DI water, to a solids content of 10%, and rod-coated onto supercalendered kraft paper using a #8 Meyer rod. The coated paper is dried and cured at 160° C. for 20 seconds.
[0080] Parting force testing is initially performed on TESA test tape 7475 made with acrylic adhesive. Parting force is measured by FINAT test methods 3 and 4. The results are presented in Table 1 below, where percent silicone refers to the percent silicone solids relative to total solids. “CRA® EM 456” is an addition curable coating containing a silicone resin to increase the parting force, and is a comparative example.
[0000]
TABLE 1
Specimen
Parting Force, 30 mm/min
Parting Force, 15 m/min
CRA ® EM 456
302 g/25 mm
73 g/25 mm
10% silicone
575 g/25 mm
182 g/25 mm
13% silicone
451 g/25 mm
114 g/25 mm
17% silicone
350 g/25 mm
51 g/25 mm
22% silicone
287 g/25 mm
51 g/25 mm
[0081] The results indicate that the inventive parting coating can provide higher parting force than that possible using a controlled release additive.
Example 2
[0082] Aqueous emulsions prepared in the same manner as in Example 1 are coated and cured onto the same paper to form consolidation liners. These coated papers are contacted with a filmic hot melt adhesive tape, TESA 4154, and tested under the same conditions as in Example 1. The results are presented in Table 2.
[0000]
TABLE 2
Specimen
Parting Force, 30 mm/min
Parting Force, 15 m/min
10% silicone
79 g/25 mm
357 g/25 mm
13% silicone
51 g/25 mm
222 g/25 mm
17% silicone
20 g/25 mm
121 g/25 mm
22% silicone
12 g/25 mm
99 g/25 mm
30% silicone
4.2 g/25 mm
38 g/25 mm
50% silicone
3.6 g/25 mm
22 g/25 mm
[0083] The results in Table 2 illustrate that a wide range of parting force is made possible by the inventive compositions.
Example 3
[0084] A 10 ply unidirectional planar laminate having dimensions of 20 cm×40 cm is prepared by laying up 10 plies of TORAYCA® carbon fiber prepreg FL66766-37E, containing unidirectional carbon fibers and 40% by weight of B-staged epoxy resin. The first ply is laid onto a consolidation liner as disclosed herein, which also is placed on top of the 10 ply uncured lay-up. The lay-up is then vacuum bagged, placed between two steel platens, and heated to 177° C. for two hours to cure. Following cure, the consolidation liners are still adhered to the cured composite. Removing the consolidation liners reveals a smooth composite surface.
[0085] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
|
Composite structures prepared by laying up a plurality of plies of thermoplastic or thermoset fiber reinforced prepregs are produced by adhering a high parting force consolidation liner on at least one surface of the layup prior to curing and consolidation. The surface coating on the release paper is preferably free of controlled release additives, adheres well to consolidated compositions, and can be removed to expose the composite surface.
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RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. Ser. No. 09/920,060, filed Aug. 1, 2001 (now U.S. Pat. No. 6,608,722), which claims priority to U.S. Ser. No. 60/222,182, filed on Aug. 1, 2000, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to an optical diffuser and method for making the same, and more particularly to an optical diffuser having a high diffraction efficiency, broadband response and cost effective method of producing the same.
BACKGROUND
[0003] Reflective diffusers are required for many applications, including liquid crystal displays, to enhance their viewability. Often these diffusers, placed behind the liquid crystal element, are simply roughened reflective surfaces. These reflectors utilize no back lighting, but instead rely on the scattered reflection of the ambient light. Unfortunately, light scattered from these devices is centered around the glare angle, which is in direct line-of-sight with the undesirable reflections from their front surface. Furthermore in many applications, such as computer screens, and perhaps watches, the preferred orientation of the device is one for which viewing at the glare angle is not optimum. The situation can be improved by using holographic diffusers which allow the reflection angles of interest to be offset, so that the maximum brightness from the diffuser falls in a preferred viewing angle which is different from that of the glare. One type of holographic diffuser that is sometimes used is the reflective, “surface-relief” hologram. This hologram has the advantage over other types in that if the ambient light is white, the reflected diffuse light is also white. Another advantage of the surface-relief hologram is that embossing can reproduce it easily and inexpensively. A major disadvantage is that the surface-relief hologram can be inefficient. Only a relatively small percentage of the incident light is diffracted into the desired viewing angles (typically less than 30 degrees).
[0004] A non-holographic diffuser, when coupled with a reflective focusing screen, uses randomly sized and randomly placed minute granules, which are created by interaction of solvent particles on plastic surfaces (See U.S. Pat. No. 3,718,078, entitled, “Smoothly Granulated Optical Surface and Method for Making Same”). These granules are dimples of extremely small magnitude (one half of a micron in depth), which reflect incident light more or less uniformly over a restricted angle. However, the angles of reflectance are very small, usually about + or −3 degrees, and the light reflected from them is here again at the glare angle.
[0005] A second kind of off-axis, holographic diffuser in common use today is the volume reflection diffuser, which can be provided by Polaroid Corporation of Cambridge Mass. With volume holograms, fringes that give rise to the diffuser reflection are distributed throughout the volume of the material, unlike the surface reflection concept of the “surface-relief” holograms. Because of this, light of a wavelength that is characteristic of the spacing distance between the fringe planes is resonantly enhanced over all other wavelengths. Thus, the reflected light is highly monochromatic. For example, if the spacing is characteristic of green, then green will be the predominant reflected color for incident white light. Unlike conventional embossed holographic diffusers, the reflection can be extremely efficient, although only over a narrow wavelength band. As a result, the surface-relief hologram can appear dim because most of the incident white light falls outside of this select band. Further processing can increase the bandwidth, thus increasing the apparent brightness, but the resulting diffuser still has a predominant hue, which is in most cases undesirable. In any event the bandwidth is still somewhat restricted, thus limiting the reflection efficiency.
[0006] Therefore, an unsolved need has remained for a diffuser having a high diffraction efficiency, broadband response and cost effective manufacture, which overcomes limitations of the prior art.
SUMMARY OF THE INVENTION
[0007] In an embodiment of the present invention as set forth herein is a blazed diffuser, which includes a reflective surface having a sawtooth structure. The sawtooth structure includes a series of contiguous wedges, each of which reflects incident oblique light into a beam which is more or less normal to the gross surface of the device. This wedge structure may be regarded as simply an off-axis mirror if the wedge spacing (period) is much larger than the wavelength. Superimposed on this wedge surface is a second structural component, which by itself diffracts incident light normal to its surface into rays, which constitute only those over a restricted narrow angle (e.g. + or −15 degrees). This angle is specified as that which is desired for a particular application. In an embodiment, this second surface shape is one that uniformly scatters an incident ray throughout the viewing angle. Such a structure gives a so called “flat top” scattering. When these two structures are superimposed, light incident from a predetermined angle which is dependent on the wedge angle, is uniformly scattered throughout a specified range of viewing angles with a high degree of efficiency. Almost all incident light is utilized and efficiencies approaching 100% for all visible wavelengths are possible.
[0008] In another embodiment, a blazed diffuser is made entirely by optical, holographic means, and it can be fabricated in such a way that the broadband spectral colors are properly mixed so that the diffracted light appears white. The recording for this diffuser is done in two primary ways. The first is by recording directly from a predetermined diffuse surface, and the second is by copying from a volume diffuser into a surface diffuser.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be more fully understood from the following description, when read together with the accompanying drawings in which:
[0010] [0010]FIGS. 1A, 1B and 1 C show a number of embodiments of the diffuser in accordance with principles of the present invention;
[0011] [0011]FIGS. 2A, 2B, 2 C, 2 D, 2 E and 2 F show a number of embodiments of reflective surfaces associated with the embodiments of the diffuser shown in FIGS. 1A, 1B and 1 C;
[0012] [0012]FIG. 3 shows the flat top diffraction profile of the surface of FIG. 2E;
[0013] [0013]FIG. 4 shows the diffraction profile of a surface which approximates that of FIG. 2E;
[0014] [0014]FIG. 5 shows the efficiency of light reflected for the structure of a preferred embodiment;
[0015] [0015]FIG. 6 shows light rays passing into and out the diffuser shown in FIG. 1A;
[0016] [0016]FIG. 7 shows interference fringe planes and the etched surface in photoresist of an embodiment of the diffuser;
[0017] [0017]FIG. 8 shows a recording configuration of an embodiment of the diffuser that uses prism coupling;
[0018] [0018]FIG. 9 shows a method for copying from a volume diffuser into photoresist using prism coupling;
[0019] [0019]FIG. 10 shows a method for making a deep stepped wedge structure by using a prism coupling;
[0020] [0020]FIG. 11 shows a recording configuration for adding diffuse reflectance to a stepped wedge structure using prism coupling;
[0021] [0021]FIG. 12 shows a recording configuration for making a fine interference fringe structure parallel to a recording surface by means of prism coupling;
[0022] [0022]FIG. 13 shows interference fringe planes and the etched surface in photoresist of a deep stepped wedge structure; and
[0023] [0023]FIG. 14 shows a theoretical diffraction efficiency for a ten-step wedge grating structure with step height=250 nm.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] The present invention provides an improved diffuser having a high diffraction efficiency, broadband response and method for making the same.
[0025] Referring to FIG. 1A, an embodiment of the present invention as set forth herein comprises an improved diffuser including a reflective surface. The reflective surface may include a periodic wedge structure 1 , as shown in FIG. 1A, which reflects incident light 2 so that incident light 2 impinges on its surface 3 from an oblique angle, θ, into rays 4 which are approximately normal to its surface. These reflected rays 4 are contained within a small angular spread if the period p of the wedge is much greater than the wavelength of the light, λ. It is essential that the wedge angle (θ/2) for the surface 3 in FIG. 1A, be selected for the particular application (e.g. θ/2=15°) and that the period p be large compared to the wavelength (typically p>100 λ). However, a period that is too large (>100 microns for example) may be visually annoying. If p is not much larger than λ, then incident light is scattered over other angles than that normal to the surface, as predicted by diffraction analysis. Furthermore the angle of scattering is then wavelength dependent, a feature that tends to detract from a desirable white diffusion pattern.
[0026] Referring further to FIG. 1B, the diffuser further includes a second structure 5 , which is disposed on the reflective surface. The second structure uniformly reflects incident rays across a prescribed angle, α. The surface 6 , which is shown in FIG. 1C, accepts an incoming oblique beam and scatters it uniformly over a range of angles, α. The scattered beam is centered on the normal to the structure with high efficiency. The geometry of the second structure 5 - or scattering structure, may itself be periodic with period q, which is smaller than, equal to, or slightly larger than the wedge period p. Such examples of these structures are shown in FIG. 2.
[0027] There are a variety of surface shapes that may be used for these structures. In the present embodiment, a shape for an element of the resulting combined surface can be described by the simple equation:
s ( x )= ax 2 +bx, (1)
[0028] where s(x) is the height of the surface and x is the coordinate on the surface, and an element is defined to span only one peak of the structure as is shown by the dimension q in FIG. 2. The second term of equation 1 represents the tilted flat surface on wedge 3 . The first term is that of a quadratic, or parabolic reflector, either positive or negative.
[0029] Simple microlens arrays may be approximated by periodic, two-dimensional parabolic surface arrays and as such have been used successfully to create flat top diffraction patterns, i.e., uniform on-axis reflection (or transmission) over a specific range of angles. Theoretically, a plane wave of incident light is uniformly reflected from a periodic surface throughout a specific range of angles because it has a constant second derivative.
[0030] In general, the diffraction from any reflective phase surface element, s(x), can include:
f ( γ ) ≈ ( 1 / q ) ∫ - q / 2 q / 2 exp [ 2 s ( x ) k ] exp [ - kx γ ] x ( 2 )
[0031] where γ is the reflection angle (radians), and k=2π/λ. For example, inserting for s(x) the parabolic function of equation 1, minus the wedge (sawtooth) portion, equation 2 yields
f ( γ ) ∼ exp [ k γ 2 / 8 a ] ∫ t 1 t 2 exp ( - π t 2 / 2 ) t
where t 1 = - 2 a / λ q + 1 / 2 a λ γ
and t 2 = + 2 a / λ q + 1 / 2 a λ γ ( 3 )
[0032] The integral in equation 3 is known as the Fresnel integral.
[0033] A typical plot of the amplitudes of the diffraction function of equation 3, is shown as the dashed curve 7 of FIG. 3. Such curves are derived by data plotted in cornu spirals, which are a convenient representation of these Fresnel integrals. As the size q of the element increases, the undulations evident at the extreme angles are reduced and the curve approaches the flat top distribution, which is desired for a preferred embodiment. However, this second component of the diffuser structure is periodic, the periodicity of which is q. For a periodic structure, the angular reflection distribution is punctuated by distinct peaks, the distance between which is proportional to the wavelength, λ, but is inversely proportional to the element size q. These peaks, which represent the various orders diffracted by the structure, are centered on the solid lines 10 shown in FIG. 3. The presence of these periodic peaks need not be detrimental to the diffuser visibility if the period q is large compared to the wavelength, in which case they will be very close together, or if the incident light is specularly broad or spatially diffuse, thus obscuring them. For the examples in FIGS. 2A and 2B, the elements 11 and 12 are as large as that of the sawtooth, i.e., q=p, which is an extreme, and perhaps a desirable case, because it also reduces the undulations in the envelope (the dashed curve) as discussed before.
[0034] For parabolic structures, the diffraction function for elements 9 and 12 , shown in FIGS. 2B and 2D, is slightly different than that represented by equation 3 due to the inverted parabolic function. The applicable equation for that surface is
f ‘ ( γ ) ∼ exp [ k γ 2 / 8 a ] ∫ t 3 t 4 exp ( - π t 2 / 2 ) t
where t 3 = - 2 a / λ q + 1 / 2 a λ γ
and t 4 = + 2 a / λ q + 1 / 2 a λ γ ( 4 )
[0035] The function f′ is the complex conjugate of f (i.e., f′=f*), a result that is evident from Fourier analysis, and so the amplitude of f′ is also represented by the dashed curve 7 of FIG. 3. Here again, a periodic structure as shown in FIG. 2D, results in peaks represented by the solid lines 10 .
[0036] The structures 13 and 14 shown in FIGS. 2E and 2F combine the elements described by equation 3 and equation 4. After addition of suitable requisite phase terms (to account for lateral shifts and pedestal phase functions), these surface components, in the absence of the sawtooth component, give diffraction functions f (γ)
f (γ)˜ e {exp [ i k γ/ 2+ k a 2 /2] f (γ)} (5)
[0037] where the symbol e refers to the ‘real part’.
[0038] Because of the additional phase terms in equation 5, the dashed curve 10 of FIG. 3 represents the maximum diffraction that is achieved. Furthermore, peaks occur in this curve at half the distance of those for the cases discussed so far, since the period of this combined structure is now 2q versus q previously.
[0039] The surface shown in FIG. 2G is particularly interesting. Each element of FIG. 2A alternates with its inversion shown in FIG. 2B to produce a surface without discontinuities. Each element of width P, is an offset parabola when equation (1) is applied.
[0040] A surface which approximates the undulating parabolic surface of FIG. 2E (disregarding the sawtooth or wedge) is that which is represented by a sine or cosine function. Such a function can be constructed from the surface relief etching of two interfering, coherent beams. A function describing such a surface can include:
s ( x )≈ c sin (π x/q ) (6)
[0041] where 2c is the peak-to-peak excursion of the function, which is periodic in 2q. Inserting this function into equation 2 results in the diffraction function
f ( γ ) ≈ ∫ - q q exp · [ 2 k c sin ( π x / q ) ] exp · [ - k x γ ] x ( 7 )
[0042] whose solution is
f(γ m )˜J m (2 k c) (8)
[0043] where J m is the m th order Bessel function of the first kind, m is an integer, and f (γ m ) represents the amplitude of the diffracted (or reflected) beams at the discrete angles of γ=mλ/p. In FIG. 4, discrete values of |f (γ m )| 2 , for example 15 and 17, are plotted for the case in which the period 2q equals 38 λ, and the angular spread is approximately ±15 degrees. As can be seen in FIG. 4, the profile 16 is not flat-topped, but peaks at specific angles ( 17 in FIG. 4). Such peaks tend to be reduced as the period, 2q, increases with respect to the wavelength, and a reasonable approximation to a flat top angular distribution is obtained.
[0044] Another method of producing a parabolic surface structure holographically is by the coherent interference of three laser beams in a layer of photoresist. If the sources of expanded light from each of the beams are arranged such that each source is approximately at the apex of an equilateral triangle, then the developed pattern in the photoresist will consist of a close-packed honeycomb array. By using suitable nonlinear etching characteristics of the photoresist, each honeycomb depression will develop in the shape of a paraboloid.
[0045] While the specific examples discussed so far relate to the reflection of incident light from a surface in air (i.e., n=1), the analysis also applies to cases in which the light is reflected from a surface that is covered, for example, by a plastic overcoating. In an embodiment, a reflective diffuser is provided, which includes a reflective surface that is embossed into the underside of a plastic sheet. In this embodiment, slight modifications to the analysis must be made, mainly in an alteration of the depth of the structure. (In equation 2, for example, s(x) becomes n s(x), where n is the index of refraction of the plastic). Also certain modifications would enable these devices to be used as transmission diffusers, rather than reflection diffusers.
[0046] Construction of surfaces discussed herein, and examples of which are shown in FIG. 1, may be carried out by a number of processes. For well defined periodic functions like those shown in FIG. 1, the surfaces can be formed by micro-machining or laser etching (e.g., MEMS processes). Alternatively the surfaces can be formed in two separate steps, which includes a first step that produces a periodic sawtooth structure such as that shown in FIG. 1A. Such a strictly periodic structure can, for example, be machined with great precision and cast into a number of materials. A second step, which adds the diffusion, or second component, may be added, for example in the following way. After appropriately coating the periodic sawtooth structure with a photoresist layer, the diffusing structure may be created by exposure to appropriate optical patterns and suitable processing of the photoresist thereafter. These optical patterns may be generated as an interference pattern of a number of coherent beams (the sine wave for example), the three-beam honeycomb pattern as described above, or as a result of scanning the photoresist surface with a focused intensity modulated light beam (as with a laser). Alternatively the optical pattern to which the photoresist is exposed may be a random function resulting, for example, from a laser illuminated diffuser. Randomly diffuse functions whose angular diffraction envelope are flat-topped, are usually difficult to create, unless unique processes are used.
[0047] The randomness may be achieved for example by using small portions of the prerequisite parabolic surface, which are randomly positioned but which on the aggregate cause reflected light to be more or less uniformly reflected over the desired angle.
[0048] Another process, described in the following, is a direct holographic method. The structure created by this method is different than that discussed so far, in that the period p is of the same order as the wavelength, λ, and thus diffraction effects become important. FIG. 5 illustrates the results of scalar diffraction theory, in which curve 18 is the major diffracted order, and the diffraction efficiency approaches 100% for the wavelength of interest. The step height h for the case shown in the FIG. 6 is equal to half the peak wavelength. For a central wavelength peak of 500 nm, the step height is thus 250 nm. This efficiency curve assumes that the surface is an ideal reflector, providing 100% efficiency at the peak wavelength. The efficiencies are also high for the entire visible spectral range, roughly ranging from approximately 85% at 400 nm in the violet to approximately 75% at 700 nm in the deep red. For this reason 500 nm is generally chosen to represent the center of the visible spectrum, and the surface structure is designed to operate at this wavelength. Note that there is a significant difference between the small scale structure represented by curve 18 , and the diffraction (or reflection) from the surface 3 of FIG. 1A. In FIG. 1A, the step height is many wavelengths, resulting in a diffraction efficiency of close to 100% for all visible wavelengths.
[0049] The parameters of FIG. 5 are chosen for the case of an air interface bordering the reflective sawtooth surface, similar to the situation shown in FIG. 1A. In the actual case, as with the situation of FIG. 1A, a preferable configuration is the coating of the surface with a protective layer, usually a clear plastic material 19 having an index of refraction, n=1.5, as in FIG. 6. The tilt angle of the sawtooth 3 is chosen to provide an optimum viewing angle normal to the surface when light is incident at the proper offset angle, which for illustrative purposes can be 30 degrees. The wedge angle, β/2, can be selected for the overcoated surface as shown in FIG. 6. Snell's Law, sin θ=n sin β, for light passing from air with index 1 into a medium with index n, yields, for an entrance angle from air of θ=30 degrees, an exit angle of β=19.47 degrees within the n=1.5 surface. The wedge tilt angle is half this value, or 19.47/2=9.74 degrees. The revised step height is h=250/n=250/1.5=166.67 nm. The period p is calculated from the grating equation for normal incidence, λ=p sin θ, or p=500/sin 30°=500/(1.5 sin 19.47°)=1000 nm=1.0 micron.
[0050] One method of creating the periodic wedge is by recording the interference of two counterpropagating laser beams, 20 and 21 in FIG. 7, in a material 22 such as photoresist (n=1.7). The equation for spacing between the interference planes, d, can include:
d=λ o /[2n sin (θ o /2)] (9)
[0051] where θ o is the half angle between the beams, and λ o is the laser recording wavelength. Thus the sine of the half angle is calculated in accordance with the following:
sin (θ o /2)=λ o /(2nd)=441.6/[(2)(1.7)(169.11)=0.76803 (10)
[0052] where a recording wavelength of λ o =441.6 nm from a He—Cd laser and an index of refraction of n=1.7 for photoresist have been used. The spacing, d, has been calculated as
d=h/[cos (β/2)=166.67/[cos(9.74°)=169.11 nm (11)
[0053] Thus equation 10 yields an angle between the beams of θ o =100.36°. The interference fringe structure, 23 , is shown in FIG. 7. This structure represents, after exposure, planes of maxima and minima of exposure intensity. When the photoresist plate is immersed in developer, etching or removal of the exposed photoresist proceeds from the top surface layer downward, the most exposed layers being removed preferentially over the least exposed layers. Ideally, the developer reaches the first zero exposure plane, which is represented by the dotted line 24 in FIG. 7. The fringe planes lying beneath this plane are not affected by the development.
[0054] The preceding discussion represents the types of calculations that must be made in order to accurately form the fringe planes, and thus the sawtooth structure in a photoresist material, which is ultimately used as a master copy for mass production. In an embodiment, at least one of the beams, 20 and 21 , in FIG. 7, can have some variation so as to create the desirable angular diffusion.
[0055] If there were no diffuse component to the beam, then the light diffracted from the sawtooth surface relief structure would, for incident white light, display all the spectral colors from violet to red, although each would be viewable from a different angle. But controlled diffusion is a requirement of this technology. Adding a diffuse component to obtain white light means adding a variation in the grating period p or in the slope of the sawtooth, so that all colors are mixed at the same diffraction angle. For example, taking the extremes of 400 nm for violet and 700 nm for red, the period p for these two colors is, respectively, p=400/sin 30°=800 nm (violet) and p=700/sin 30°=1400 nm (red) for the same diffraction angle of 30 degrees. If these extremes in the period for the visible spectrum are now present as part of the surface relief structure, then the diffraction angles for the design wavelength of 500 nm range from 38.68 degrees to 20.92 degrees, so that the total variation is 8.68+9.08=17.76 degrees. Since the diffuser is nominally designed to operate at an angular spread of plus or minus 15 degrees from the main diffraction angle of 30 degrees (or a total angular spread of 30 degrees), there is sufficient angular variation for mixing the entire visible spectrum sufficiently to produce white light.
[0056] A method for making the diffuse structure is to use a split beam holographic setup and a predetermined diffuse surface. This method allows for flexibility in the range of recording angles. The method does, however, require the fabrication of a diffuse plate with the requisite viewing angles, which is inserted into at least one of the two recording beams. In one configuration, as shown in FIG. 8, requires the use of two prisms, 25 and 26 , with a liquid gate plate holder contacted by index matching liquid to both prisms. The calculated angles for beam 20 with respect to the normal, i.e., 49.56 degrees, is so large that it exceeds the critical angle, θ c , which is θ c =arcsin (1/n)=arcsin (1/1.7)=36.03 degrees. In the absence of a coupling medium, i.e., an air interface, all incident light would be at almost normal incidence to the face of the equilateral prism 25 . Beam 20 enters the face of the opposite prism 26 such that the angle of incidence to the photoresist material 22 from the n=1.5 glass layer is equal to 34.61 degrees. In this case the fringe spacing and tilt angle in the photoresist are as required for the example above. Because the angle of incidence of beam 20 does not exceed the critical angle into photoresist, an alternative scheme allows beam 20 to enter the tank directly from air at 58.43 degrees, A third alternative is one in which the rectangular plate holder tank is immersed in a large square tank filled completely with index matching liquid, thus eliminating the prisms altogether. While this latter method is relatively easy to implement it does require great care in allowing the index matching liquid to completely stabilize before making the recording.
[0057] Copying directly from a volume diffuser, as an alternative to the above, has many advantages. One advantage relates to a volume diffuser with the requisite offset and viewing angles, which can be efficiently produced holographically. Another advantage relates to the copying procedure, which is simpler than direct recording using a predetermined diffuse master, provided certain conditions are met. One of these conditions is that the peak wavelength of light diffracted from the master falls roughly into the center of the visible spectral range. Also the volume diffuser, which is used for copying, can have the proper angular spread to create an adequate viewing angle in the reflective mode.
[0058] A method of forming a structure like that of FIG. 7 from a volume hologram is shown in FIG. 9. In order to form such a structure we assume that (1) photoresist 22 , is in intimate contact with the holographic diffuser 27 , (2) beam 21 is incident from outside, passing through the photoresist and into the volume hologram, (3) beam 20 is reflected from the interference planes 28 within the volume hologram back through the photoresist layer and (4) the index of refraction of the volume hologram has a typical value of n=1.5. Thus copying is done with only a single beam.
[0059] In order to create beams 20 and 21 at angles of 49.56 degrees and 30.08 degrees (as shown in FIG. 7), these beams, denoted as 29 and 30 in FIG. 9, must have angles of 59.61 degrees and 34.61 degrees respectively in the lower index material 27 (n=1.5). Such beams exist in the volume reflective hologram 27 only if it contains fringe planes tilted at 12.5 degrees as shown in FIG. 9, and whose spacing d=216.28 nm. This assumes that the copy wavelength is 441.6 nm. Light incident normally onto these fringe planes will reconstruct coherently at a wavelength of λ=2nh=2(1.5)(216.28)=648.85 nm, which is red. This result points out a fundamental characteristic of this type of construction; namely, that copying into a high index material at large incidence angles from a lower index master, requires that the master be red-shifted with respect to the copy. In other words, reconstruction of a blazed surface pattern producing light peaked in the green spectral region requires a master peaked in the red spectral region. Such a volume hologram can be easily made with a conventional holographic setup using red laser light (e.g., a Kr laser at 647 nm or a He—Ne laser at 633 nm) and either red-sensitive photographic emulsion or photopolymer. It is also possible to copy from a photopolymer master diffuser that is already tuned to the green spectral region, provided that certain steps are made to convert the diffuser to the red region. For example, the green Polaroid Imagix diffuser photopolymer can be copied directly into a DuPont 706 photopolymer, using either green laser light at near normal incidence or blue 441.6 nm laser light at a large angle of incidence. The DuPont material can then be tuned to the red region using DuPont CTF color tuning film, which essentially swells the photopolymer to a larger thickness, thereby increasing the spacing between the planes and changing the color from green to red.
[0060] Here again the angle for beam 20 in the photoresist is greater than the critical angle (49.56>36.03) and we must resort to coupling by means of a liquid gate. The photoresist plate is placed in a rectangular tank containing an index matching liquid for glass at n≈1.5 (e.g., xylene) that is liquid coupled to an equilateral prism, as shown in FIG. 9.
[0061] Variations of the methods disclosed here can result in efficient directional diffusers. For example, with the first type disclosed, uniform angular spreading of the incident beam may be accomplished by a variation of either the period p or the slope θ/2 from sawtooth element to sawtooth element. However, such a procedure may require that the element size p be reduced (for example from 100 λ to 10 or 20 λ) so as to preserve the smooth visual texture of the diffuser. If the size p is too large, visible portions of the diffuser will not scatter into the observation direction.
[0062] A variation of the holographic method discussed herein, is the addition of a fine diffusing structure to a coarse wedge structure. This coarse wedge structure is of larger dimensions than that of the methods described in FIGS. 7 and 8, and can be constructed in the following manner, as shown in FIG. 10. Two beams enter the photoresist layer 33 that is coated onto a glass substrate 34 from the same side 35 at an oblique angle, such that the interference fringe structure 36 is coarse and inclined at some angle with respect to the surface. Prism coupling allows for a large degree of obliquity in a manner similar to that shown in FIG. 9.
[0063] A diffuse component can be added in a second exposure step by contacting the photoresist layer 33 to a reflective diffuser 39 , as shown in FIG. 11. In this case the incident beam 37 is totally reflected as a diffuse beam 40 that encompasses a range of angles. The contact can be done using either a liquid gate, or by reversing the plate and attaching the diffuser directly to the glass substrate and using a liquid gate between the photoresist and the prism. For this procedure to be effective, the resist should be coated to a several micron thick layer. The first exposure should be done at a laser wavelength for which absorption is large, for example 441.6 nm, so that the amount of reflected light is minimal. The second exposure should be done at a longer, less absorbing wavelength, for example 457.9 or 476 nm, so that the reflected beam is nearly equal in intensity to the incident beam.
[0064] An alternate technique adds a fine step structure to the coarse wedge of FIG. 10, in place of the fine diffusing structure. With this technique the second exposure uses two beams that enter the photoresist from opposite sides so that the interference fringe structure is fine and parallel to the surface. This is also done by prism coupling, using a single beam 37 that is totally reflected that interferes with itself, as shown in FIG. 12, with the fine fringe structure designated as 38 . For this exposure the photoresist plate is reversed so that the surface 35 faces out. When the photoresist is developed after the composite exposure, the resulting structure is a deep wedge-shaped grating that has a fine stepped grating superimposed onto it (FIG. 13).
[0065] The diffraction efficiency for a ten-level structure is shown in FIG. 14 and includes the spectral distribution for diffracted orders +2, +1, 0, −1, and −2. Also included in this plot is the spectral distribution for a single-step blazed grating, which is identical to FIG. 5. It is clearly evident that the spectral distribution for the single-step shallow blazed grating forms an envelope for the ten-level deep stepped grating. The number of orders that appear under this envelope decreases as the number of levels is reduced, but their individual spectral width increases.
[0066] As can be seen from FIG. 14, the diffraction is specularly discrete, allowing only narrow band color components to be observed at any given viewing angle. In order to avoid this often undesirable result, the photoresist can be exposed in narrow adjacent stripes that yield, for example, red, blue, and green light diffracted at the same angle to produce white. The proper angle for light diffracted from the stepped grating structure is determined by the periodicity of the coarse wedge grating, and that periodicity depends, in turn, on the oblique angle that the interference fringe structure makes with respect to the photoresist surface.
[0067] Another variation on this method consists of first making a wedge grating structure of large periodicity and adding the step structure or diffuse structure to it holographically. In this configuration, it is similar to the structure shown in FIG. 1 c . For the step structure, the procedure consists of coating the wedge structure with a thin, uniform layer of photoresist, which can be done either by dip coating or by spin coating. The coated wedge surface is then immersed in an index-matching liquid gate that is optically contacted to an equilateral glass prism, as described above. The step structure is made by exposing to a totally reflecting beam of laser light that is coupled to a diffuse surface, also described above. With this method many more diffracted orders are obtained than with the totally holographic method described above, due to the much greater depth of the preformed structure compared to that obtained holographically, but with diffuse mixing the diffracted light appears white.
[0068] The discussion has focused on devices that uniformly scatter light through a solid angle. But in some applications it may be desirable to achieve non-uniform scattering. One can modify the processes to create blazed diffusers that have a wide range of scattering properties.
[0069] Both categories of structures have been described in the foregoing in reference to their scattering properties in one dimension only. That is, the emphasis has been on showing how an incident beam whose obliquity to the surface (i.e., θ=30°) is scattered uniformly throughout an angle α, as in FIG. 1. But in the other direction, which follows the coordinate going into the paper in all of the Figs., the illumination beam 2 (See FIG. 1) is assumed to have no obliquity, but to impinge perpendicular to the surface. In order to obtain a uniform angular diffusion, there is a similar requirement for scattering over an angle of α in this dimension also, albeit without an offset θ. For the first category of diffuser described here, the surface profile into the paper for the surface of FIG. 2 would contain the parabolic component, thus providing a diffuser, each portion of which scatters uniformly throughout a pyramidal solid angle which is offset from the incident illumination by angle θ. Similarly if a beam, which is randomly diffuse throughout a cone of angles, is reconstructed as beam 20 in FIG. 9 from the photopolymer hologram 27 , the resulting aluminized diffuser will scatter incoming light throughout a conical solid angle, offset by angle θ.
[0070] Having thus described at least one illustrative embodiment of the invention, various alterations, modifications and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements are intended to be within the scope and spirit of the invention. Accordingly, the foregoing description is by way of example only and is not intended as limiting.
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A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.
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BACKGROUND OF THE INVENTION
The present invention relates to the manufacture of terry cloth and, in particular, to apparatus for achieving a uniform ratio of pile to the ground warp which constitutes the fabric's foundation.
For many years terry cloth was produced utilizing conventional fly shuttle looms. Such looms weave a product with a uniform pile-to-ground warp ratio, but they typically operate at a relatively slow rate. More recently, however, fly shuttle looms have been replaced with high speed weaving machines such as the Models PU and TW 11 looms produced by Sulzer Brothers Limited of Winterthur, Switzerland. Various aspects of these types of machines are the subject of several publications, including U.S. Pat. Nos. 3,871,419, 4,122,873 and 4,569,373.
In a Sulzer machine, ground and pile warps move past a reciprocally operable reed and a displaceable rocking bar. The ground warp continuously is dispensed from its supply beam, while the pile warp is dispensed incrementally from its supply beam under the control of a pile warp let-off motor. A weft or filling yarn is inserted between the reed and the movable rocking bar in the weaving operation, and as the reed are displaced towards the rocking bar during their reciprocation, the filling yarn is carried by the reed to the fell of the cloth being woven.
In a typical weaving cycle, the rocking bar is maintained at a first position as the filling yarn is carried to the fell twice in succession in the manner just described. Before the reeds are displaced a third time, however, the pile warp let-off motor dispenses pile yarn, and the rocking bar is displaced to move the fell of the cloth towards the reeds. As a result, when the reed carries the filling yarn to the fell of the cloth, loops of the pile yarn are formed in a row across the top and bottom of the base fabric. The rocking bar then is withdrawn to its initial position to permit the three-pick weaving cycle just described to be repeated.
The height of the loops in terry cloth is very important to its acceptability. In a typical high pile terry, approximately 55% of the total fabric is pile yarn. Any fluctuation in pile height (i.e., a change in the pile-to-ground warp ratio) has an adverse effect on the fabric's weight and appearance.
Two kinds of pile warp let-off can be used in a terrying operation. The first is a positive type pile let-off, a mechanically-linked device which lets-off a predetermined amount of terry yarn based on a mechanical adjustment. The second type--employed in a Sulzer machine--is a negative pile let-off motor which controls let-off in dependency on pile warp tension, the amount of terry yarn dispensed being that required to maintain constant tension on the pile warp.
Terry looms with a motorized negative-type let-off attempt to control the pile-to-warp yarn ratio by monitoring the tension of pile yarn at a location near its supply beam. More particularly in one known version of a Sulzer machine, the ends of pile yarn pass over a flexible beam as they are fed into the loom. A metallic flag is secured to the beam so as to move towards or away from the pile yarn supply beam as the beam flexes in response to the amount of tension applied to the pile warp ends. A proximity sensor is mounted adjacent the flag. This sensor produces an output voltage having a magnitude dependent on the distance between it and the flag. As tension on the pile warp ends changes, the flag's movement alters the sensor's output voltage. This output voltage is supplied to circuitry for producing signals for increasing or decreasing the speed of the pile warp let-off motor to alter the amount of pile yarn dispensed from its supply beam thus maintaining constant tension on the yarn. As the pile warp tension increases, the pile warp let-off motor accelerates so as to decrease the tension. Conversely, a lowering of pile warp tension results in the pile warp let-off motor being slowed in order that the pile warp tension will increase.
An arrangement analogous to that just described for controlling pile warp tension is described in the aforesaid U.S. Pat. No. 4,569,373.
While the arrangements just described contribute to the control of the pile-to-ground warp ratio by maintaining the tension of the pile warp within a normal operating range, the terry height nevertheless still can vary by an unacceptable amount.
SUMMARY OF THE INVENTION
The present invention results from the recognition that a pile-to-ground warp ratio can be maintained substantially uniform by controlling not only the pile warp tension, but also the distance the rocking bar moves during the weaving operation. Since adjustment of the amount of rocking bar displacement in a terry loom with a motorized negative-type let-off is performed manually when the machine is stopped, such adjustment cannot be employed for continuously controlling the pile-to-ground warp ratio. The present invention provides means, however, for automatically adjusting both the distance the rocking bar moves and the tension of the pile warp in order to maintain the pile-to-ground warp ratio substantially constant, thereby producing uniform terry.
DETAILED DESCRIPTION OF THE INVENTION
The invention now will be described in greater detail with respect to the accompanying drawings which illustrate a preferred embodiment of the invention, wherein:
FIG. 1 is a side elevational view illustrating the general arrangement of a terry weaving machine according to the present invention; and
FIG. 2 is a block diagram of electronic circuitry employed for controlling the pile-to-ground warp ratio.
Referring to FIG. 1, the basic weaving machine illustrated is a well-known and commercially available Sulzer loom which includes a ground warp supply beam 10 and a pile warp supply beam 12. Yarn from each of these beams is directed around beams and past harnesses to the area 14 where weft or filling yarn (not shown) is woven through the warp yarns in the customary fashion. Area 14 lies between an oscillating reed 16 and a rocking bar 18, the latter being reciprocally movable along a path extending in the direction of warp yarn travel. As they move towards bar 18, the reed 16 positively carries the filling yarn to the fell of the cloth being woven. The cloth thereafter moves past a needle-type take-up beam 20 which rotates at constant speed, and then is collected by a final beam 22.
The ground warp yarn is removed continuously from beam 10. The rate of removal is controlled by the take-up beam 20. In the Sulzer machine incorporating the present invention, the ground warp yarn passes over a deflecting and tensioning beam arrangement 11 of the type disclosed, for example, in the aforesaid U.S. Pat. No. 4,122,873. Thus, the amount of warp yarn dispensed from beam 10 is continuous and is a known quantity which remains constant throughout the weaving operation. The pile warp yarn is dispensed from beam 12 in response to signals to the pile warp let-off motor 24.
As the pile warp yarn leaves beam 12, it passes over a tensioning beam 26. Beam 26 is of the type disclosed, for example, in the aforesaid U.S. Pat. No. 3,871,419, the beam being pivotally mounted for deflection. A flag 28 is attached to beam 26, the outer end of the flag being positioned adjacent to a fixed proximity sensor 30 of the type disclosed, for example, in the aforesaid U.S. Pat. No. 4,569,373. When the tension on the pile warp varies, beam 26 deflects, thus altering the distance between the flag 28 and sensor 30. The sensor thereby produces an electrical output signal which is a function of pile warp tension.
An encoder 32 also is operably related to the pile warp yarn as it is discharged from beam 12. The encoder 32 is a conventional device commonly employed in industrial applications to produce an electrical output as a function of rotation imparted to a roller portion of the encoder. An encoder suitable for this purpose is the commercially available Accu-Coder Model 716-S manufactured by Encoder Products Co. of Sandpoint, Id. This type of encoder produces a given number of output pulses for each revolution of its roller. As it is employed as part of the present invention, the encoder roller spring-biased against the pile warp yarn wound on beam 12 producing, as the beam rotates, an electrical signal which accurately indicates the rate of yarn discharge from the beam. This rate is, of course, directly the amount of yarn dispensed from the beam.
The signals from the encoder 32 and sensor 30 are utilized in a manner now to be described in order to maintain a substantially constant pile-to-ground warp ratio.
As illustrated in FIG. 2, the output signal from encoder 32 is directed to circuitry 34 which includes a microprocessor. The circuitry also incorporates appropriate memory which stores information relating both to the amount of ground warp yarn dispensed and programming for the microprocessor. Since delivery of the ground warp yarn is controlled by the constant speed of take-up beam 20, the amount of ground warp being dispensed from beam 10 is a known quantity. Thus, data which accurately represents how much warp yarn the constant speed motor 20 is dispensing from beam 10 can be entered into the memory portion of circuitry 34, together with instructions for causing that data to be inputted to the microprocessor and a calculation to be performed in conjunction with the signal inputted to the microprocessor from encoder 32, the latter signal representing the pile warp yarn being dispensed. With these inputs, the microprocessor continuously computes the pile-to-ground warp ratio occurring as the loom operates. If the ratio departs from a pre-programmed desired level, the microprocessor's output, when combined with that developed by proximity sensor 30, produces a signal which alters the operation of the pile warp let-off motor 24 to perform a limited adjustment to the rate at which pile warp yarn is discharged from beam 12. This is accomplished by applying the microprocessor and sensor outputs to a conventional summation circuit, the output of which is directed to known circuitry ("Sulzer Electronics") found in commercially available Sulzer machines. This circuitry performs the basic timing and control functions necessary for loom operation. As it pertains to the present invention, a further function of the Sulzer Electronics is to control pile warp tension in the manner by which that function is achieved through the operation of the electronic programmed control device described in the aforesaid U.S. Pat. No. 4,569,373. More particularly, the pile warp supply beam 12 is either speeded up or slowed down, in response to changes in the pile warp tension, by varying the control signals to the motor. This causes either an increase in the amount of pile yarn dispensed when the pile-to-ground ratio is too low, or a decrease in the pile yarn dispenser when the ratio is too high. As a result, the tension of the pile warp is maintained constant.
The control of the pile-to-ground warp ratio obtainable by varying just the operation of pile warp let-off motor 24 is limited, however. Accordingly, the present invention provides additional control of large excursions of the ratio by means now to be described.
The circuitry 34 includes conventional threshold detector means for the recognition of error in excess of a predetermined level. When this occurs, the detector's output is directed to a motor controller 36 which in turn is joined to a further motor 38. This motor operates a lead screw arrangement (hereinafter described in detail) associated with rocking bar 18 so as to alter the displacement of bar 18. As a result, the minimum spacing "x" which occurs between the reed 16 and the fell of the cloth being woven is altered. When spacing "x" increases, the height of the pile increases, while a decrease of the spacing "x" results in the pile height decreasing.
The signal from the threshold detector directed to motor controller 36 is of a predetermined interval only. Thus, the adjustment of the rocking bar 18 is incremental. This provides the circuitry 34 with an opportunity to determine whether the adjustment of the displacement of bar 18 has been sufficient to bring the pile-to-ground warp yarn ratio to a level where it can be controlled by the signals generated by sensor 30 and encoder 32. If an error sufficient to produce an output signal from the threshold detector persists after an incremental adjustment of rocking bar 18 occurs, another such adjustment is made. This process is repeated until the desired pile-to-ground warp ratio can be attained solely by the operation of pile warp let-off motor 24.
The mechanical arrangement by which the rocking bar 18 is adjustably displaced is illustrated in FIG. 1. More particularly, bar 18 is secured to the upper end of an arm 40 which is pivotally connected to a stationary support member 42. Arm 40 is forked at its lower end, one portion of the fork being omitted from FIG. 1 for convenience of illustration. A horizontally disposed arm 44 is arranged with one of its ends located within the fork of arm 40. The other end of arm 44 is operatively connected to a cam drive (not shown) which reciprocates the arm after each third pick of the weaving process to permit reed 16 to "beat" the pile warp into the fell of the cloth being woven. The end of arm 44 located within the fork of arm 40 is provided with an elongated slot 46 to receive a pin 48 secured at its ends to the fork. A block 50 also is located within slot 46. The block is joined to a lead screw 52 threaded into arm 44. The lead screw 52 is joined by a flexible drive cable 54 to motor 38. Thus, as motor 38 operates, block 50 is moved along slot 46. Repositioning of the block varies the degree of displacement imparted to the lower end of arm 40 by the uniform horizontal movement of arm 44 produced by the cam drive. The motor 38 has associated with it a rotary limit switch 60 which is set to turn off the motor when the rocking bar 18 is adjusted to its maximum and minimum limits.
The rocking bar 18 is interconnected with a slide 56 which reciprocates horizontally in response to the arcuate movement of bar 18 caused when the lower end of arm 40 is displaced. Slide 56 carries at its outer end a spiked roll 58. The spikes penetrate the cloth produced by the weaving operation. Roll 58 turns only in response to the tension applied to the cloth by the take-up roll 20. Consequently, when the rocking bar 18 is displaced to permit the pile warp to be beaten into the fell, roll 58 supports the fell.
Changes in amount of movement of rocking bar 18 alter the amount of pile warp which is beaten into the fell. Stated otherwise, by increasing the displacement of bar 18 towards the reed 16, a higher pile is developed, while reducing the travel of bar 18 towards the reed lowers the pile height.
Since the electronics employed in the present invention recognize deviations from a desired pile-to-ground warp ratio, it is apparent that the error signals developed also can be used to energize suitable indicators to show when the cloth being produced is not within an acceptable range.
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The pile-to-ground warp yarn ratio of terry cloth is controlled during the weaving operation by sensing both the tension imposed on the pile warp and the amount of pile warp yarn dispensed from its supply beam. The sensed information is used to control the speed of a pile warp let-off motor which dispenses the pile warp yarn from its beam. Additionally, the sensed information is employed to selectively alter the displacement of a rocking bar to vary the height of the terry loop formed in the cloth.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. Provisional Patent Application No. 60/241,086 titled “Wireless Communications Invisible Proxy and Hooking Systems and Methods”, filed Oct. 17, 2000, co-pending herewith and which is hereby incorporated herein by this reference.
The present application is related to U.S. Pat. No. 6,166,729, entitled “Remote Digital Image Viewing System and Method”, issued Dec. 26, 2000 (CPA filed Oct. 26, 1999); U.S. Provisional Patent Application No. 60/177,329, entitled “Wireless Network System and Method”, filed Jan. 21, 2000; U.S. Provisional Patent Application No. 60/180,649, entitled “Digital Image Transfer System and Method”, filed Feb. 7, 2000; and U.S. Provisional Patent Application No. 60/220,730, entitled “Wireless Network System and Method,” filed Jul. 26, 2000, each of the same inventor hereof, and those respective applications are incorporated herein. The present application is also related to U. S. Provisional Patent Application No. 60/241,096, entitled “Wireless ASP Systems and Methods,” filed Oct. 17, 2000, U.S. Provisional Patent Application No. 60/241,095, entitled “E-Mail and Messaging Systems and Methods,” filed Oct. 17, 2000, U. S. Provisional Patent Application No. 60/241,087, entitled “Wireless Communications Protocols and Architectures Systems and Methods,” filed Oct. 17, 2000, and U.S. Provisional Patent No. 60/240,985, entitled “Browser and Network Optimization Systems and Methods,” filed Oct. 17, 2000.
BACKGROUND OF THE INVENTION
The present invention generally relates to wireless communications systems and methods and, more particularly, relates to systems and methods for wireless packetized data communications using specialized protocols and integration interfaces for operations of standard applications.
Conventional packetized data communications protocols and network architectures were developed primarily for use in wired networks and conditions. The protocols and networks are not optimized for the peculiarities of wireless communications environments. Networks, particularly client-server networks such as the Internet, are commonly designed to conform to standardized protocols, for example, the Transport Control Protocol/Internet Protocol (TCP/IP). Software and hardware applications of client devices that are connected to and communicate over these networks, therefore, generally are capable of communicating according to the TCP/IP or other standard protocol.
Where specialized or non-standard protocols are employed in communications on networks, these applications typically are not readily susceptible to communicating according to the specialized protocols. In the past, the applications have generally been re-written or modified to adapt to specialized protocol platforms and other communications nuances. For example, conventional practice has been to replace system DLL files or to use a proxy changing application (e.g., a browser) settings. Of course, such modifications are often costly, time-consuming, or inconvenient. Moreover, the general trend and concern of the communications industry is often expressed to be standardization and integration among multiple platforms and scenarios.
It would be a significant improvement in the art and technology to provide systems and methods for enabling standard software and hardware applications capable of communicating with certain protocols to be capable of communicating with other specialized protocols of networks, such as the Internet and particularly wireless environments, without requiring significant modification of the applications themselves.
SUMMARY OF THE INVENTION
An embodiment of the invention is a wireless communications network. The network includes a wireless communications channel, a wireless application service provider (ASP) server computer communicatively connected to the wireless communications channel, and a client device communicatively connected via the wireless channel to the wireless ASP server computer. The wireless ASP server computer communicates with the client device over the wireless communications channel by a specialized protocol. In certain embodiments, a hooking layer of the client device translates the specialized protocol to a standard protocol for use by standard applications programs of the client device.
Another embodiment of the invention is a method of wireless communications. A client device communicates wirelessly with a wireless application service provider (ASP) server computer. The client device runs standard programs. The method includes serving a first information by the wireless ASP server computer to the client device according to a specialized protocol, determining that the first information accords with the specialized protocol, and proxying the first information to the standard programs in a standard protocol readable by the standard programs.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example and not limitation in the accompanying figures, in which like references indicate similar elements, and in which:
FIG. 1 illustrates a network, for example, the Internet, including a wireless communications portion and a wireless application service provider (ASP) system including a wireless ASP server computer in wireless communications with a wireless device;
FIG. 2 illustrates a hooking layer for intercepting standardized format communications and serving as an invisible proxy to specialized format communications, according to embodiments of the present invention; and
FIG. 3 illustrates a method of operation of the hooking layer of FIG. 2 , according to embodiments of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Network with Wireless ASP System
Referring to FIG. 1 , a communications system 100 includes a wireless communications portion and a wired communications portion. The system 100 includes a network, such as the Internet 102 . The network is operable according to a particular packetized data protocol, such as transport control protocol/Internet protocol (TCP/IP) or some other network protocol. The network, such as the Internet 102 , interconnects various computing and communications devices, for example, among other devices, a server computer 104 and a wireless ASP server computer 106 . The server computer 104 and the wireless ASP server computer 16 are each one or more server computers including a microprocessor, memory storage, and communications capabilities via wire or wireless connection with the Internet 102 . The server computer 104 and the wireless ASP server computer 106 communicate over the Internet 102 or other network via the particular protocol of the network, such as the standard Internet network protocol TCP/IP.
The network, such as the Internet 102 , is also connected with a wireless communications service provider 108 . The wireless communications service provider 108 is, for example, a cellular or other packetized data wireless communications network, such as a cellular digital packet data (“CDPD”) or other network. The wireless service provider 108 connects by wire connection with the network, such as the Internet 102 . Alternatively, the wireless communications service provider 108 could connect with the network 102 by other communications connection, such as fiber optic, coax cable, wireless channel, or other communications connection. Furthermore, although the wireless communications service provider 108 is illustrated as a single particular communications channel, multiple links and multiple channels of those links, for example, communications links of wired and wireless channels, can alternatively provide the same functions and are included for purposes of the description.
The wireless service provider 108 is capable of communicating through wireless channels with various devices, such as a wireless device 200 . The wireless device 200 is a processing device, such as a data-enabled cellular telephone, a personal digital assistant, a laptop computer, or any of a wide variety of other processing devices that can wirelessly communicate with the wireless service provider 108 . Of course, the wireless device 200 includes communications equipment for accomplishing the wireless communication with the wireless service provider 108 , such as wireless modem.
The wireless device 200 communicates through the wireless service provider 108 and over the network, such as the Internet 102 , with the wireless ASP server computer 106 . The wireless ASP server computer 106 serves as a dedicated server for the wireless device 200 in its communications. The wireless ASP server computer 106 sends and receives communications to and from the wireless device 200 over the network, such as the Internet 102 , and on through the wireless service provider 108 . The wireless ASP server computer 106 also communicates over the network, such as the Internet 102 , with other network connected devices, such as the server computer 104 , via particular protocols in communications channels enabled for such communications on the network. In certain embodiments, for example, the wireless ASP server computer 106 and the wireless device 200 communicate with specialized protocols, such as optimized packetized data protocols, for example, optimized TCP/IP protocols or other protocols such as described in the related patent applications.
Communications between the wireless ASP server computer 106 and the wireless device 200 over the network, including through the wireless service provider 108 and the wireless portion, are performed according to special optimized, non-standard protocols and formats. Communications between the wireless ASP server computer 106 and other portions and elements of the Internet, for example, with the server computer 104 , are performed according to different protocols and formats, such as standard networking formats like TCP/IP. For purposes of example here, the network protocol is that of the Internet 102 (i.e., TCP/IP) and certain embodiments of non-standard protocols and formats, for the wireless communications between the wireless ASP server computer 106 and the wireless device 200 , are described in the related patent applications. The optimized protocols and formats are not limited to those of the related applications, however, and the same principles and concepts described herein apply to other situations and designs, as well.
Referring to FIG. 2 , the wireless device 200 of FIG. 1 includes various standard or typical application programs 202 . These programs 202 include, for example, a browser (e.g., Internet Explorer™), an FTP application (e.g., Bullet Proof™ FTP), and an e-mail client application (e.g., Eudora™). The programs 202 can, of course, be software applications, or firmware or hardware implementations. In any event, the programs 202 receive or use communications over the network's typical protocols, such as TCP/IP, which differ from the specialized protocols of communications between the wireless device 200 and the wireless ASP server computer 106 . The wireless device 200 also includes communications elements 204 , such as a wireless modem and applications for communicating with the wireless ASP server computer 106 over the wireless portions of the network 200 . The communications elements 204 include features for communicating with the wireless ASP server computer 106 according to the specialized protocols for such communications, as previously mentioned and as described in the related patent applications.
Additionally, the wireless device 200 also includes a hooking layer 206 , operably connected between the programs 202 and the communications elements 204 . The hooking layer 206 is implemented either in hardware or software and is resident on or communicatively connected to the wireless device 200 . The hooking layer 206 functions to allow communications of signals received by the communications elements 204 to be communicated, via either an application-standard socket (e.g., Winsock) or a specialized socket (i.e., Sockhook), between the communications elements 204 and the programs 202 in forms acceptable to the programs 202 . In effect, the application-standard protocol data received by the wireless device 200 is passed to the programs 202 via the standard sockets and any non-standard specialized protocol data received by the wireless device 202 is translated to be acceptable to the programs 202 .
Particularly, the hooking layer 206 includes sets of the standard dynamic link libraries (DLLs) (e.g., Winsock.dll) associated with the programs 202 . The hooking layer 206 also, however, includes a specialized set of non-standard DLLs (i.e., Sockhook.dll) that are specific for the specialized protocols and allow for appropriate action of the programs 202 in connection with communications according to the specialized protocols of the network 100 . As those skilled in the art will know and appreciate, the non-standard DLLs of the hooking layer 206 will depend upon the particular specialized protocols. In any event, the hooking layer 206 serves, in effect, as an invisible proxy to the programs 202 to make communications received by the wireless device 200 useable by the programs, whether such communications conform to standard network protocols or specialized optimized protocols.
Referring to FIG. 3 , a method 300 of operation of the wireless device 200 and the hooking layer 206 is a form of switch that determines the applicable DLLs for the protocols of the communications and then provides an applicable socket for the programs 202 . The method 300 , when a communication is received by the wireless device 200 , for example, a wireless communication, commences with a step 302 of receiving the communication 302 . The communication is received in the step 302 by the modem and other communication elements of the wireless device 200 .
In a step 304 , the hooking layer 206 determines whether standard or non-standard sockets are appropriate, based on whether the received communication conforms to standard protocols or non-standard protocols, respectively. If the communication conforms to standard protocols of the network 100 , for example, TCP/IP protocols of the Internet, then the hooking layer 206 invokes the standard sockets and standard DLLs, such as Winsock sockets and Winsock.dll. The communication is then conveyed via the socket to the programs 202 , and the application performed by the programs 202 is run in a step 308 .
If, on the other hand, the communication is determined by the hooking layer 206 to be non-standard protocols, such as optimized wireless protocols of the related patent applications or others, then the hooking layer 206 invokes appropriate non-standard DLLs and acts as an invisible proxy in a step 312 . As an invisible proxy in the step 312 , the hooking layer 206 serves to interact with the received communication and the programs 202 by providing the information of the communication to the programs in form acceptable to the programs 202 . In acting as an invisible proxy, the hooking layer 206 sets up a non-standard socket (i.e., Sockhook) and uses the non-standard DLLs (i.e., Sockhook.dll). In effect, the hooking layer 206 in the step 312 receives the communication information in the form of the non-standard protocols, such as of the wireless portion of the network 100 , and manipulates the information to the form of the standard protocols of the network 100 , such as TCP/IP. The hooking layer 206 , acting as invisible proxy in the step 312 , provides the communicated information to the programs 202 for a step 308 of running the programs 202 using the information in acceptable form to the programs 202 .
In transmission communications of the wireless device 200 , the substantial reverse of the method 300 occurs. The application is run in a step 308 , and the result is delivered to the hooking layer 206 . At the hooking layer 206 , the hooking layer 206 again serves as an invisible proxy in a step 312 , although this time the hooking layer 206 manipulates the information from a standard protocol form to the non-standard protocols. The hooking layer 206 invokes the specialized socket and specialized DLLs for the manipulation, in the steps 304 , 310 , 312 . The wireless device 200 then transmits in a step 302 the information, formatted according to the specialized protocols, for example, the optimized wireless protocols. These specialized protocols are, thus, employed over the wireless portion of the network 100 in communications both ways between the wireless device 200 and the wireless ASP server computer 106 .
In operation of the systems 100 , 200 and the method 300 , numerous alternative business and technical arrangements are possible. Of course, the wireless ASP server computer 16 must be capable of communicating via typical network protocols with other network connected devices in order to receive and deliver messages from and to those network connected devices, and then transfer those messages on or receive those messages from the wireless device 20 , as appropriate. Moreover, although only particular devices of a communications network and its nodes are herein described and discussed, particularly, primarily the wireless device 200 and the wireless ASP server computer 106 , the wired device 240 and the network 100 , such as the Internet, have been described with regard to the embodiments, it is to be expressly understood that combinations of those elements, such as a plurality of any, certain ones, all of those elements, and even additional or alternative elements, is possible in keeping with the scope of the embodiments herein.
The network could be an intranet, or even an intranet combination or intranet-extranet combination. Numerous banks of the wireless ASP server computer 16 can be possible for receiving communications from pluralities of wireless devices, and the wireless ASP server computers can be centrally located or distributed through a wide geographic area. In the case of a global network such as the Internet, the network is capable of communicating by its protocols, which may include other specialized protocols for specific situations.
The wireless ASP server computer in such instance can communicate with various devices on the network according to those other specialized protocols, if properly equipped as would be known to those skilled in the art. In general, the communications between the wireless device or devices and the wireless ASP server computer or computers occurs according to optimized protocols for wireless communications. These optimized protocols can be implemented entirely in software or alternatively can be hardware, combinations of hardware and software, or other mechanisms. The protocols of the hardware or software, as the case may be, for the wireless communications will, in any event, provide increased communications efficiency, speed, and adaptation for the wireless environment.
In the foregoing specification, the invention has been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature or element of any or all the claims. As used herein, the terms “comprises, “comprising,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
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An communications service provider provides wireless access to a packetized data network, such as the Internet. The service provider includes a server computer. The server computer is connected to the network, which is at least in part a wired network. The wired network is connected to a cellular wireless communications system. A method of the network includes a client device that communicates wirelessly with the server computer. The client device runs standard applications programs, such as browser, ftp, and e-mail. The method includes serving a first information by the server computer to the client device according to a specialized protocol, determining that the first information accords with the specialized protocol, and proxying the first information to the standard programs in a standard protocol readable by the standard programs.
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This invention related to a well fluid sampling tool and to a well fluid sampling method.
BACKGROUND OF THE INVENTION
Reservoir fluids (liquids (such as water or oil) and gas) are found in geological reservoirs wherein they are contained at a high pressure (relative to ambient atmospheric pressure), and usually also at an elevated temperature (relative to ambient atmospheric temperature). At such pressures, the gas is dissolved in the liquid such that the reservoir fluid initially exists as a single-phase fluid, but the reservoir fluid will release dissolved gas to form a two-phase fluid with separate gas and liquid components if the reservoir fluid has its initial pressure sufficiently reduced towards ambient atmospheric pressure. Also, the initial relatively high temperature of the reservoir fluid results in volumetric contraction of a given mass of fluid as it cools towards ambient atmospheric temperature if withdrawn from the well.
When hydrocarbon exploration wells, for example, are drilled and hydrocarbon fluids are found, a well fluid test is usually performed. This test usually involves flowing the well fluid to surface, mutually separating the oil and gas in a separator, separately measuring the oil and gas flow rates, and then flaring the products (or transporting the products elsewhere for use or safe disposal).
It is also desirable to take samples of the reservoir fluid for chemical and physical analysis. Such samples of reservoir fluid are collected as early as possible in the life of a reservoir, and are analysed in specialist laboratories. The information which this provides is particularly-vital in the planning and development of hydrocarbon fields and for assessing their viability and monitoring their performance.
There are two ways of collecting these samples:
1. Bottom Hole Sampling of the fluid directly from the reservoir, and
2. Surface Recombination Sampling of the fluid at the surface.
In Bottom Hole Sampling (BHS) a special sampling tool is run into the well to trap a sample of the reservoir fluid present in the well bore. Provided the well pressure at the sampling depth is above the "Bubble Point Pressure" of the reservoir fluid, all the gas will be dissolved in the liquid, and the sample will be a single-phase fluid representative of the reservoir fluid, i.e. an aliquot.
Surface Recombination Sampling (SRS) involves collecting separate oil and gas samples from the surface production facility (e.g. from the gas/liquid separator). These samples are recombined in the correct proportions at the analytical laboratory to create a composite fluid which is intended to be representative of the reservoir fluid, die a re-formed aliquot.
Several BHS tools are currently available commercially, which function by a common principle of operation. A typical BHS tool is run into the well to trap a sample of reservoir fluid at the required depth by controlled opening of an internal chamber to admit reservoir fluid, followed by sealing of the sample-holding chamber after admission of a predetermined volume of fluid. The tool is then retrieved from the well and the sample is transferred from the tool to a sample bottle for shipment to the analytical laboratory. As the tool in retrieved from the well, its temperature drops and the fluid sample shrinks causing the sample pressure to drop. This pressure drop occurs because the sample-holding chamber within the typical BES tool has a fixed volume after the sample is trapped and because the sample temperature is uncontrolled. Usually the sample pressure falls below the Bubble Point Pressure, allowing gas to break out of solution. This means the sample is now in two phases, a liquid phase and a gas phase, instead of in single-phase form as it was before the pressure dropped. In order successfully to transfer the sample from the tool to the sample bottle, it is necessary to pre-pressurise the sample sufficiently to force the free gas back into solution, recreating a single-phase sample. This recombination is a lengthy procedure and thus expensive.
The temperature change which the sample experiences and the resultant pressure change may also cause the precipitation of compounds previously dissolved in the well fluid, some of which cannot be re-dissolved by re-pressurisation. The absence of these compounds in the re-formed aliquot renders certain analyses meaningless.
A means by which a well fluid sample could be collected, retrieved and transferred in single-phase form, without a pressure-induced phase change, would a mitigate these problems. Not only would time spent recombining a two-phase sample back to single phase be saved, but pressure-sensitive compounds would remain dissolved, allowing more accurate analyses to be performed on the sample. One such means is described in our co-pending European Patent Application EP-A-0515495, which utilises pressurisation of the sample to maintain the sample in single-phase form.
In more general terms, it is also desirable to retrieve a sample whose temperature is close to its original temperature.
BRIEF SUMMARY OF THE INVENTION
According to a first aspect of the present invention there is provided a well fluid sampling tool comprising a sample chamber; operative means for the tool operative to admit a well fluid sample to said sample chamber; and temperature maintenance means for maintaining the temperature of a well-fluid sample held within said sample chamber, the temperature maintenance means acting to counteract changes in temperature of the sample.
Preferably, the temperature maintainteance means acts to maintain said well fluid sample in single-phase form.
Preferably, the temperature maintenance means is formed as a storage heater.
Said temperature maintenance means may comprise heat retention means which preferably comprises thermal insulation means disposed to minimise heat loss from a well-fluid sample at an elevated temperature relative to ambient temperature and held within the sample chamber. Said thermal insulation means preferably comprises a heat insulating jacket at least partially surrounding the sample chamber, the jacket being formed of a material or materials having a low thermal conductivity and preferably also exhibiting low thermal radiation characteristics. The jacket preferably also has a high specific heat capacity. Said thermal insulation means may additionally or alternatively comprise an evacuated jacket at least partially surrounding the sample chamber. The evacuated jacket may comprise at least part of the heat insulating jacket.
Said temperature maintenance means may additionally or alternatively comprise heat generation means for generating heat in or adjacent the sample chamber. The heat generation means preferably comprises electrically energised electric heater means conveniently in the form of a dissipative resistor disposed on and/or in the sample chamber. The resistor may be in the form of an elongate tape wound around the sample chamber. Alternatively, the resistor may be in the form of a resistive coating. Electrical energy for energisation of the electric heater means may come from batteries or any other suitable source of electrical energy comprised within the sampling tool; additionally or alternatively, the electrical energy may come from an out-of-tool source, e.g. a wellhead generator, and be conveyed to the sampling tool by means of an electric cable.
According to the second aspect of the present invention there is provided a well fluid sampling method comprising the steps of providing a well fluid sampling tool comprising a sample chamber, lowering said tool down a well to a location where well fluid is to be sampled, admitting a sample of well fluid into said sample chamber and then sealing said sample chamber, and maintaining the temperature of the well fluid sample held within the sample chamber while raising the tool and the sample up the well, in a manner tending to counteract changes in temperature of the well fluid sample.
Preferably, the sampled well fluid is maintained in single-phase form.
In said method of well fluid sampling, said well fluid sampling tool is preferably a well fluid sampling tool according to the first aspect of the present invention.
The method may comprise the step of holding the tool adjacent the sampling location, or in another region of elevated temperature, for a period at least sufficient to elevate the temperature of the sample chamber towards the anticipated temperature of the sample to be taken. The method may comprise the alternative or additional step of pre-heating the sample chamber prior to lowering the sampling tool down the well.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings wherein:
FIG. 1 diagrammatically illustrated the order of assembly of FIGS. 2A-4G to form composite figures;
FIGS. 2A-2G (assembled as indicated in FIG. 1 to form a composite FIG. 2) illustrate a longitudinal section of a well fluid sampling tool in accordance with the invention, the tool being in a pre-sampling configuration;
FIGS. 3A-3G (assembled as indicated in FIG. 1 to form a composite FIG. 3) illustrate the tool of FIG. 2 in its sampling configuration, i.e. in the process of sampling a surrounding well fluid; and
FIGS. 4A-4G (assembled as indicated in FIG. 1 to form a composite FIG. 4) illustrate the tool of FIG. 2 in its post-sampling configuration.
DETAILED DESCRIPTION OF THE INVENTION
Before describing the embodiments in detail, it will be mentioned that the illustrated embodiment has much in common with the well-fluid sampling tool described in our co-pending European Patent Application EP-A-0515495, though the present invention is fundamentally different in at least one important respect. The following description will concentrate on the novel aspects of the embodiments, and for complete details of other aspects, reference should be made to the published specification of the aforementioned EP-A-0515495.
Referring first to composite FIG. 2, a well-fluid sampling tool 10 comprises an elongate linear assembly (within a multi-component casing) of a clock 12, a clock-actuated trigger assembly 14, an air chamber 16, a trigger-actuated valve 18, a sample inlet valve 20, a sampling piston 22, a sample chamber 24, and a wireline connector 26 at the top of the tool 10. Details of the afore-mentioned components and sub-assemblies of the tool 10 are given in the published specification of EP-A-0515495, except for details of the novel sample chamber 24, which are given below.
The sample chamber 24 comprises an inner tube 30 of a material having properties suitable for use as a sample chamber, i.e. mechanical strength and durability, and resistance to chemical attack by well fluids. The material of the inner tube 30 is also selected to have a high specific heat capacity.
The sample chamber 24 further-comprises an outer tube 32 of a thermally insulating material also having a high specific heat capacity, as well as adequate mechanical properties and corrosion resistance. The material of the outer tube 32 may be a suitable ceramic or be formed of steel having a thermally insulating coating.
The annulus 34 between the inner and outer tubes 30, 32 may be evacuated such that the vacuum around the sample chamber 24 further improves thermal insulation of the sample chamber 24. The annulus 34 may be filled with an aerogel as an additional insulating material.
The exterior of the inner tube 30 is wound with an electrical resistance heater 36 in the form of a tape or foil or may be coated with a resistive coating. The heater 36 is connected (by means not shown) to a control circuit and battery pack (not shown) mounted inside a battery chamber 38 forming part of the sampling tool 10 between the upper end of the sampling chamber 24 (the right-hand end of the sample chamber 24 as viewed in FIGS. 2, 3 & 4) and the wireline connector 26.
Electric power for the heater 36 may additionally or alternatively be supplied from an external generator or electric mains (not shown), conveniently though an electric cable (not shown) paralleling (or serving in place of) the wireline (not shown) coupled to the wireline connector 26 (which is suitably adapted to the transfer of electric power as well as mechanical lifting forces).
Operation of the well-fluid sampling tool 10 will now be described.
On the surface above the well whose fluid is to be sampled, the tool 10 is prepared for sampling operation by setting the internal components to the positions shown in FIG. 2 (in particular, setting the sampling piston 22 to the lower (left) end of the sample chamber 24), evacuating the annulus 34 through a re-closable valve 40, setting (but not yet initiating operation of) the clock 12 to respond after a predetermined time delay, and pressurising the upper (right) end of the sample chamber 24 above the piston 22 with hydraulic oil. The hydraulic oil is injected through a priming valve 42 until the upper end of the sample chamber 24 is filled with oil at a pressure greater than the fluid pressure at the location where the sample is eventually to be taken.
The pre-pressurisation holds the piston 22 against the bottom of the sample chamber 24 against upward force on the piston 22 produced by the pressure of well fluids entering the initially open sample inlet valve 20, until the piston 22 is released for sample taking by opening the valve 18 within the trigger assembly 14 to depressurise the hydraulic pre-filling by draining it into the air chamber 16.
If necessary or desirable, the sample chamber 24 is pre-heated by energising the heater element 36, using either the batteries (previously charged and installed in the battery chamber 38) or an external power supply, such as a wellhead generator or mains power. The inner tube 30, together with the heater element 36 and suitable further thermal insulation, may be combined as a form of storage heater which may be detachable from the rest of the tool 10 for convenience in pre-heating and other purposes (e.g. sample handling and sample chamber cleaning).
The prepared tool 10 is connected to a wireline (not shown) by means of the connector 26 and lowered down the well to the location at which a well fluid sample is to be taken. If the tool 10, and the sample chamber 24 in particular, are not yet at or near the ambient temperature at the sampling location, the tool 10 is suspended at the sampling location until temperature equilibrium is approached or reached. (While beneficial in ways which are detailed below, the thermal insulation of the sample chamber 24, and the high specific heat capacity of the sample chamber materials make the sample chamber slow to warm up to downhole ambient temperature; pre-heating reduces this delay).
At the preselected time, the clock 12 reaches the end of the pre-set delay period and actuates the trigger assembly 14 to open the valve 18 as shown in composite FIG. 4, allowing hydraulic oil to drain from the upper (right) end of the sample chamber 24 into the air chamber 16. This allows the sampling piston 22 to move up (rightwards along) the sample chamber 24 under the pressure of well fluid entering the lower (left) end of the sample chamber 24 through the sample inlet valve 20. The rate at which hydraulic oil flows into the air chamber 16 is metered to control the rate at which well fluid enters the sample chamber 24 to level low enough to avoid a pressure drop across the valve 20 that would otherwise cause dissolved materials to come out of solution in the liquid component of the well fluid.
As the sample chamber 24 becomes filled, the piston 22 abuts a closing sleeve 44 defining the upper (rightward) end of the sample chamber, and through a hollow pull-rod 46 (part of the path by which hydraulic oil was drained from the chamber 24 to the chamber 16), further upwards (rightward) movement of the piston 22 pulls the sample inlet valve 20 to its closed position as illustrated in composite FIG. 4. Apart from the pre-heating step, the above described part of the sampling procedure is more fully detailed in our co-pending European Patent Application EP-A-0515495.
Once the sample inlet valve 20 is closed, the downhole part of the sampling procedure is complete, and the sampling tool is pulled back up the well to the surface, with the hot, high-pressure well fluid sample sealed inside the sample chamber 24. The initial temperature of the well-fluid sample, i.e. the temperature of the well fluid at the time of sampling, is substantially maintained by the storage heater arrangement and by the structure of the sample chamber 24, i.e. by the thermal isolation provided by the use of thermally insulating material for the outer tube 32, together with the evacuation of the annulus 34 between the outer and inner tubes 32 & 30, and also by the high specific heat capacities of the materials selected to form the tubes 30 and 32.
If the sample temperature should commence to fall significantly, such a temperature fall would be detected by the control circuit (in the chamber 38) through a sample temperature sensing means (not illustrated), for example a thermistor or thermocouple in thermal contact with the sample. In response to the detected temperature drop, the control circuit would connect the batteries (also in the chamber 38) to the heater 36 so as to heat up the underlying inner tube 30 and thereby maintain the sample against untoward cooling.
The highly desirable effect of maintaining the temperature of the sampled well fluid at or near initial as-sampled temperature is the preservation of the initial volume of the sampled well fluid without the volumetric shrinkage otherwise induced by is temperature reduction, and consequently the maintenance of the well-fluid sample at or sufficiently near its initial pressure as to obviate loss of the initial single-phase condition of the sample otherwise induced by shrinkage.
In our co-pending European Patent Application EP-A-0515495, the initial single-phase condition of the well fluid sample was maintained by externally pressurising the sample chamber from an in-tool pressure source as soon as the sample was taken; in the present invention the initial single-phase condition of the well-fluid sample is maintained by maintaining the temperature of the sample sufficiently to prevent cooling of the sample to the point at which there would be significant loss of single-phase condition, and without resort to internal pressurisation of the sample chamber.
Modifications and variations of the above-described preferred embodiment can be adopted without departing from the scope of the invention as defined in the appended Claims.
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A well fluid sampling tool and method for retrieving reservoir fluid samples from deep wells. The sampling tool is lowered to the required depth, an internal sample chamber is opened to admit well fluid at a controlled rate, and the sample chamber is then automatically sealed. The temperature of the sampled well fluid is maintained at or near initial as-sampled temperature to avoid the volumetric shrinkage otherwise induced by temperature reduction, mitigate precipitation of compounds from the sample, and/or maintain the initial single-phase condition of the sample. The sample chamber is thermally insulated, provided with a storage heater, electrically heated, given a high hear capacity, and/or pre-heated to sample temperature.
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This application is a continuation of application Ser. No. 08/149,003, filed Nov. 8, 1993, abandoned which is a continuation of Ser. No. 07/761,633, filed Sep. 18, 1991, abandoned.
This invention relates to a process for the partial oxidation of bituminous oil emulsion whereby the emulsion is separated, the bituminous oil is preheated to a temperature which adequately reduces its viscosity, and the emulsion water--after concentration--is added to the bituminous oil as an additional moderator for partial oxidation.
BACKGROUND OF THE INVENTION
In the Orinoco Basin, in Trinidad, in North America, and in other areas, deposits of heavy oil and asphalt occur which are noted for their high bitumen content. These natural substances--which resemble oil and are commonly known as bituminous oil--can only be extracted by processes reducing viscosity and not by standard refinery methods. The extraction method currently used in the Orinoco Basin comprises emulsification of the bituminous oil at bed level, extraction of the emulsion, upgrading and transport. During the further processing stage, the saline emulsion water of the primary emulsion is replaced by river water with low salt content. This secondary emulsion can be temporarily stored and transported by pipelines or oil tankers.
Emulsifying the bituminous oils with water brings about a considerable reduction in the viscosity of these oils. The original viscosity in excess of 10000 cP at ambient temperature is reduced to the range of 400 to 1200 cP as a consequence of emulsification. It is only this viscosity-reducing process that permits the extraction, transport and further processing of bituminous oil. The water content of the emulsion is approximately 30% by weight, i.e. 70% by weight bituminous oil.
Owing to this high bitumen content, the bituminous oil cannot be processed by traditional refinery methods.
At present, the bituminous oil emulsion is used to fire power stations. The high sulphur content in bituminous oils (from 3 to 4%) causes a correspondingly high level of environmental pollution--a level which is becoming more and more unacceptable in the industrialized countries. The alternative is to produce desulphurized fuel gas by partial oxidation of bituminous oil emulsion, thus obtaining raw gas mainly consisting of CO and H 2 . The raw gas is subsequently treated to obtain desulphurized fuel gas suitable for firing combined cycle power plants. Jochen Keller describes the combined cycle power plant--in other words, a gas and steam turbine process with upstream partial oxidation (gasification)--in his article entitled Diversification of Feedstocks and Products: Recent Trends in the Development of Solid Fuel Gasification Using the Texaco and HTW Process published in FUEL PROCESSING TECHNOLOGY No. 24 (1990: pp247-268) by Elsevier Science Publishing B. V. Amsterdam. Said report is, however, confined to the gasification of solid fuels.
The partial oxidation of viscous fuels such as mineral oil residues from vacuum distillation units, said oxidation taking place during gasification, is already known and, consequently, gasification is feasible in a combined-cycle power station using viscous fuel. Please consult: L. Nelson & J. Brady New Opportunities for Fuel Oil in Power Generation: Heavy Residue Gasification Schemes--a paper presented at the Institute of Petroleum in London on Feb. 19, 1990.
A special kind of viscous fuel is the above-mentioned bituminous oil emulsion, the extractions nd properties of which are discussed by I. Layrisse, H. Rivas et al in Production, Treatment and Transportation of a New Fuel: Orimulsion (TM)--in a paper presented at the 12th International Conference on Slurry Technology held in New Orleans, La./USA, from Mar. 31 to Apr. 3, 1987. In addition to CO, H 2 , CO 2 and CH 4 , the raw gas from the partial oxidation of the bituminous oil emulsion contains one to two percent carbon black--with reference to the oil deployed--and sulphurous ingredients such as H 2 S and COS. The carbon black and the sulphurous ingredients are removed by repeated gas scrubbing whereas the purified gas is pressurized and fed as fuel to a gas turbine.
The partial oxidation of bituminous oil emulsion is also suitable for the generation of synthesis gas or hydrogen--in other words, as an intermediate process step for a wide range of chemicals such as methanol, ammonia, oxy-products, formic acid and acetic acid.
The concepts for partial oxidation of bituminous oil are based on the low viscosity of the bituminous oil emulsion which permits pumping and atomizing of the emulsion in a burner currently used for the gasification of oil.
The oil gasification burner guides the reactants--bituminous oil emulsion and oxygen--into the gasification reactor and atomizes the bituminous oil emulsion at the burner mouth due to the high gas flow velocity of the reactants. Atomization is only possible as long as the liquid feedstock possesses a viscosity which does not exceed an average of 2000-3000 cP. The high water content of the bituminous oil emulsion adversely affects the process because the water evaporates in the gasification zone and the vapor is heated to the gasification temperature of 1300°-1500° C. This extra heat requirement causes an additional consumption of oxygen and oil.
OBJECTS OF THE INVENTION
The aim of the invention is to design a process for partial oxidation of bituminous oils that prevents the penetration of a relatively large quantity of emulsion water into the reaction chamber and reducing the specific consumption figures of bituminous oil and oxygen.
It is an object of the present invention to provide a process for the oxidation of a bituminous oil emulsion having a viscosity no higher than about 3000 cP (centipoise measured by Burell-Severs Rheometer at 100° F., 40 psi k=0.2325) with oxygen or air to provide a product gas comprising CO and H 2 , the processing comprising the steps of:
A. separating a bituminous oil emulsion into bituminous oil and emulsion water,
B. concentrating the emulsion water by removing water,
C. reacting the bituminous oil, the concentrated emulsion water and oxygen to partially oxidize the bituminous oil and provide product gas.
It is an object of the present invention to provide a process that saves power and uses less bituminous oil and oxygen, the process for the partial oxidation of bituminous emulsions to provide a raw gas comprising CO and H 2 , the process comprising the steps of:
A. feeding a preheated bituminous oil emulsion to an emulsion separator and separating the oil emulsion components to obtain a separated bituminous oil product and a separated emulsion oil water product.
B. evaporating the emulsion oil water product to remove water and provide a concentrated emulsion oil water,
C. feeding the bituminous oil product to a gasification unit means,
D. feeding the concentrated emulsion oil water with the bituminous oil to the gasification means, and
E. reacting the bituminous oil and the concentrated emulsion water, and oxygen to provide raw gases comprising CO and H 2 .
These and other objects will be apparent from the specification that follows, the appended claims, and the drawings, in which:
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flowsheet of a process for the partial oxidation of bituminous oil emulsions according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The problem of reducing the consumption of bituminous oil and oxygen has been solved because the invention provides for a heating process in which the bituminous oil emulsion is separated into bituminous oil and emulsion water, in which the bituminous oil is further heated to the atomization temperature of the bituminous oil and in which only a portion of the original emulsion water is added as a gasification moderator to the bituminous oil, once the organically impure emulsion water has been concentrated by evaporation. Steam can be utilized as additional moderator. The high thermal requirements for the evaporation of emulsion water are, in this case, not satisfied by additional gasification feedstock but by low-pressure steam which is obtained in every plant for partial oxidation and not suitable for recovery. Low-pressure steam is used to evaporate the emulsion water.
According to the embodiment of the invention, air or oxygen are deployed as oxidizing agent for the partial oxidation of bituminous oil emulsion, the purity grade of oxygen required to optimize the process being within the range of 50% to <99.8% by volume. It is surprising to find that the process according to this invention opens up the possibility of exploiting either air (containing about 20% by volume of oxygen) or oxygen of low purity (50-65%) as oxidizing agent since the fuel bituminous oil has been liberated from its non-combustible ingredient, i.e., the emulsion water.
According to the conception laid down in the invention, the emulsion water bearing heavy hydrocarbons is concentrated and subsequently eliminated by gasification. The high gasification temperature ensures complete oxidation and conversion into CO, H 2 , CO 2 and other simple gas components.
The evaporation of the emulsion water can be taken so far that the quantity of moderator needed for the partial oxidation is greater than that of evaporated emulsion water. In this case, the differential amount can be made up by recycled carbon black bearing water from the plant for partial oxidation or waste water from another plant.
Carbon black is contained in the craw gas as a result of partial oxidation and is removed by scrubbing with water. The water obtained has a low carbon black concentration of about 0.5 to 1.5% by weight. In downstream process stages, the carbon black content can be increased to about 20% in a carbon black/water mixture.
Adding to the optimization of this new process is the fact that the vapors resulting from the evaporation of the emulsion water can be deployed either to preheat the bituminous oil emulsion and/or, once said vapors have been compressed to form low-pressure steam, to evaporate the emulsion water.
The condensates resulting from cooling of the vapors are used as quench water for the hot raw gas emanating from the gasification. Thus, the freshwater requirement for the quenching stage is also reduced.
In fuel gas production plants, an alternative is to utilize the vapor condensates for the saturation of the desulphurized fuel gas, i.e., the input mass flow to a gas turbine is increased in order to use the extra heat at a low temperature level for the generation of electricity or for the reduction of the NOx emissions with the aid of moderated combustion.
In the event of the emulsion water having a high salt content, the water is subjected to desalination which can be carried out upstream or downstream of the evaporation phase. The desalination can be effected by ion exchange, reverse osmosis or electrodialysis.
The bituminous oil separated from the emulsion is preheated to operational temperature, pumped to the partial oxidation unit operating above atmospheric pressure and thus undergoes an increase in pressure. This preheating can take place either before or after pressurization.
FIG. 1 illustrates an embodiment of the invention, and the process is described below:
FIG. 1 shows that the bituminous oil emulsion from pipe 1 is preheated in heat exchanger 3 to 100° C.-130° C. depending on the vapor quantities which are fed from the emulsion water evaporation unit via pipe 2. The preheated emulsion is fed to heat exchanger 7 via pipe 4 and heated generally to about 130° C.-170° C. and preferably to about 140° C.-160° C. with the aid of low-pressure steam via pipe 6. The emulsion now destabilized by the rise in temperature is fed via pipe 9 to emulsion separator 10, which can comprise either a gravity-type emulsion separator or a combination of gravity separator and downstream emulsion separator in the electrostatic field. The bituminous oil with a residual water content of about 1/2 to 1% up to 3 to 4% is transferred via pipe 11 to the bituminous oil heater 28 heated by medium-pressure steam fed via pipe 27. The bituminous oil, whose outlet temperature is at least about 200° C., and preferably at least about 225° C. to 250° C., is conveyed via pipe 29 to intermediate storage facility 31. The viscosity of the bituminous oil at said temperature is generally lower than about 3000 cP. The hot bituminous oil in pipe 32 is brought to a pressure exceeding the gasification pressure by means of high-pressure pump 33.
The steam condensates are withdrawn from heat exchanger 7 via pipe 8 and from bituminous oil heater 28 via pipe 30.
The emulsion water in pipe 12 flows to the evaporation unit 14 which uses low-pressure steam from pipe 13 at a pressure of about 2 to 5 bar abs. In order to save low-pressure steam, the vapors, or a certain portion of said vapors from the pipes 17 and 18, can be brought to the required feed steam pressure with the help of the vapor compressor 19 and then fed to the evaporation unit via pipe 20.
The vapors, or a certain portion of them from pipe 17, are fed via pipe 2 to preheat the bituminous oil emulsion in heat exchanger 3.
The condensed vapors from pipes 5 and 16 are utilized to quench the hot raw gas obtained during partial oxidation.
The evaporated emulsion water withdrawn via line 15 is pressurized by high-pressure pump 21 so that its pressure is above that of gasification. The concentrated emulsion water is conveyed via pipe 22 to emulsion water heater 25 and heated to a temperature of more than about 200° C., using medium-pressure steam via pipe 24. The steam condensate is withdrawn via pipe 26. The concentrated emulsion water is piped via pipe 35 to line 34 conveying bituminous oil and added, the mixture being fed gasifier 39. Said emulsion water is utilized both as moderator in the gasification step to limit the gasification temperature and as an oil atomizing agent encouraging rapid evaporation at burner mouth where the temperature exceeds generally about 1300° C., and preferably 1350° C. up to about 1400° C. or 1500° C. Thanks to the heating of the concentrated emulsion water, the consumption of oxidizing agents is reduced and the cooling of bituminous oil avoided.
The partial oxidation of bituminous oil is performed in the gasification unit 39. The bituminous oil (via pipe 34), the emulsion water as moderator (via pipe 35) and oxygen or air (via pipe 38) are fed into the gasification chamber via the gasification burner. At the burner outlet, the reactants are atomized and mixed, the exothermic partial oxidation taking place between 1300° C. and 1500° C. The pressure of gasification is generally about 10 to 90 bar, and preferably about 40 to 70 bar. The raw gas in pipe 40 mainly consists of CO and H 2 ; other ingredients are CO 2 , CH 4 , H 2 O, H 2 S, COS, N 2 and Ar.
Another embodiment provides for high-pressure steam added via pipe 36 to the hot bituminous oil in pipe 34 in addition to the evaporated emulsion water from pipe 35; this is feasible if a change in the properties of the carbon black obtained in gasification unit 39 is required.
A further embodiment provides for the following: either the recycled carbon black-bearing water suspension from the quench section of the gasification unit or the waste water, which is difficult to dispose of, is added as gasification moderator to the residual emulsion water via pipe 23. In this case, the evaporation of the emulsion water is taken so far that the required overall quantity of moderator water from pipe 35 exceeds the amount of evaporated emulsion water from pipe 15. The required differential amount of water is compensated via pipe 23. Should the carbon black-bearing water suspension be piped via line 23, it can be fed to the gasification unit either as diluted suspension or as carbon black slurry.
The enclosed Table A reflects different embodiments of this invention: processes Ia and Ib, as well as state-of-the-art process designated "Process II", the previous level of technology.
Embodiments of this invention related to partial oxidation of bituminous oil emulsion by means of evaporation of the emulsion water:
Ia: The quantity of evaporated emulsion water, pipe 15, corresponds to the required amount of moderator, pipe 35.
Ib: The quantity of evaporated emulsion water, pipe 15, is less than the required amount of moderator, pipe 35. The required difference is recycled carbon-black-bearing water suspension or waste water, pipe 23.
Table A reveals that the gasification of bituminous oil emulsion causes a considerable extra consumption if compared to the gasification of bituminous oil and evaporated emulsion water for the generation of the same quantity of useful gas, CO and H 2 .
5% more bituminous oil, 16.3% more oxygen and correspondingly more electrical energy for the generation of high-pressure oxygen.
Given an energy assessment of the consumption figures based on the electric current which could be specifically generated:
--for saturated steam: 0.12 MW el./t steam
--for bituminous oil: 4.4 MW el./t oil
The saved power amounts to 10.4 MWh/h when implementing the process of partial oxidation of bituminous oil on the basis of the invention as opposed to the partial oxidation of bituminous oil emulsion.
TABLE A__________________________________________________________________________THE PARTIAL OXIDATION OF BITUMINOUS OIL (I)COMPARED TO THE PARTIAL OXIDATIONOF BITUMINOUS OIL EMULSION (II) PARTIAL PARTIAL OXIDATION OXIDATION OF BITUMINOUS OF BITUMINOUS OIL OIL EMULSION Unit Pipe Var. Ia Var. Ib II__________________________________________________________________________Gasification feedstockBituminous oil emulsion t/h 1 61.4 61.4 64.5bituminous oil t/h 1 43.0 43.0 45.15emulsion water t/h 1 18.4 18.4 19.35Evap. emulsion water t/h 15 9.7 2.5 --Carbon-black-bearing water t/h 23 -- 7.2 --or waste waterOxygen 100% kmol/h 38 1431.7 1431.7 1665.7Oxygen purity Mol. % 99.5 99.5 99.5GenerationCO + H.sub.2 Nm.sup.3 /h 114800 114800 114800Requirements foremulsion separationLP steam 5 bar (abs.) t/h 13 7.9 8.4 --LP steam 8 bar (abs.) t/h 6 3.6 1.7 --MP steam 20 bar (abs.) t/h 24.2 73.8 3.8 --Elec. energy kWh/h -- -- 210 --Vapour compressionExtra consumption of kWh/h -- -- -- 2800electric power forgeneration of O.sub.2__________________________________________________________________________ (calculated for a gasification pressure of 65 bar abs.)
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A process for the partial oxidation of bituminous oil emulsions to produce a raw gas containing CO and H 2 , the process including heating the bituminous oil emulsion to destabilize the emulsion and separating the bituminous oil from the emulsion water, concentrating the emulsion water by evaporation, and reacting in a gasification unit the bituminous oil, the concentrated emulsion water and oxygen or air to produce the raw gas containing mainly CO and H 2 .
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TECHNICAL FIELD
The present invention relates to a method for producing and coating melt portions, in particular melt adhesive portions, in which the melt is deposited in portions onto an endlessly circulating, horizontal conveyor belt. A first coating material layer is fed onto the surface of the upper end of the belt of the conveyor belt and a second coating material layer partly is applied onto the melt portions deposited on the first coating material layer and partly covering the surface of the melt portions. The present invention is also directed to a system and a device for the application of a melt in defined melt portions for the system.
BACKGROUND OF THE INVENTION
A system for the coating of melt adhesive portions is known from the German patent specification DE 93 18 554 U1. The system disclosed in this specification exhibits an endless circulating horizontal conveyor belt that is coated with a powdery coating material at the feed side. Then, a melt adhesive is applied in defined melt adhesive portions onto the moving conveyor belt. In an additional work station, a powdery coating material layer is applied onto the surface of the melt adhesive portions from above. Then, the melt adhesive portions that are coated on both sides with the coating material pass through a heating station that liquefies the powder of the coating material and that causes an even coating of the melt adhesive portion. A cooling area is attached to the heating station, in which the coated melt adhesive portions are cooled down. After having passed the cooling area, the melt adhesive portions are removed from the conveyor belt and packed in larger units.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a method as well as a system of the above-mentioned kind that guarantees a faster and enhanced production and coating of melt adhesive portions.
This object is accomplished in that two sheet strips are continuously fed as coating material layers, the material properties of which are adjusted to the melt regarding chemical tolerance, and that the thickness of the melt portions imbedded between the sheet strips is calibrated in thickness, the melt portions are cooled, the sheet strips are connected to each other by closely encompassing each melt portion, and the sheet strips are cut lengthwise and crosswise to the conveying direction of the melt portions such that the melt portions become isolated. A smooth coating of the melt portion that can be easily handled is already achieved by providing the sheet strips without providing the heating station, as is provided in the related prior art, with the result that the expenditure of energy and thus also costs for the method of the present invention are reduced. The calibration of the thickness of the melt portions results in a more even and more defined cooling so that--compared with the related prior art--an improved cooling behavior is achieved. The sheet strips can be connected in the transition regions between the adjacent melt portions either before or after separating the sheet strips and the resulting isolation of the melt portions. The method according to the invention can be used for all molten masses, but it is particularly well suited for melt adhesives, the strongly adhesive surface of which has to be coated for easier further handling. Due to the chemical tolerance of the sheet strips with the melt, the melt is not impaired by the sheet material.
In one embodiment of the invention, the melt is prepared to have a specified viscosity at a specified temperature and is then applied step by step on the conveyor belt in equal portions, thus achieving even and consistent portioning. In addition, by preparing the melt, it is well adapted to the following cooling of the melt portions on the conveyor belt.
In a further embodiment of the invention, the melt portions are inserted into appropriate matrix spaces of a grid mask that is assigned to the conveyor belt and which travels with the latter and is disposed underneath the lower sheet strip. In this instance, the volume of the melt portion is adjusted to the free volume of each matrix space such that the molten mass overflows over the rims of each matrix space. The thickness of the calibrated melt portions is also greater than the height of the grid mask. By overflowing over the rims of each matrix space, the molten mass itself forms the connection between the two sheet strips forming the top and the bottom covering layers, because it adheres to the two sheet strips. This embodiment is particularly advantageous for melt adhesives having a strong adhesive surface. Contrary to other embodiments of the present invention, welding or gluing the sheet strips may be avoided in this embodiment. The molten mass overflowing over the rims has only a minor thickness so that the two sheet strips are only connected along the rims in an extremely small distance. Due to the grid mask, it is possible to achieve an individual shaping of the melt portions according to the form of the matrix spaces.
In another embodiment of the invention, before feeding of the sheet strips to the conveyor belt, a separating layer is inserted or provided between the underside of the first sheet strip resting on the conveyor belt or the grid mask and the surface of the conveyor belt or the grid mask. This prevents the sheet strip from adhering to the surface of the conveyor belt or the grid mask and causing damages when the melt portions are loosened.
In another embodiment of the invention, an additional separating layer is inserted or provided between the surface of the second sheet strip that touches an upper conveyor belt during calibration and cooling, and the belt surface of the conveyor belt. This separating layer also serves to facilitate an easy detachment of the sheet strip from the surface of the top belt after passing the cooling region.
In another embodiment of the invention, a water spray forms each of the separating layers. In addition to serving as a separator, water also has an additional cooling function in that the sheet strips touching the melt portions are cooled by the water layer between the respective belt surface and the assigned sheet strip.
For the system, the object according to the invention is accomplished in that the conveyor belt is part of a twin belt cooler used for cooling and that a storage roll equipped with a removable sheet strip is assigned to the conveyor belt and to the upper endless circulating belt of the twin belt cooler such that the sheet strips travel with the two belts at the end of the belts that face each other. A significant advantage using a twin belt cooler is that a calibration of the melt portions is achieved in its thickness, which makes a particularly even and defined cooling of the melt portions possible.
In another embodiment of the invention, the melt temperature of the sheet strip is lower than the processing temperature of the melt. As soon as the melt portions including the coating by means of the sheets are fed into a melt bath, the sheets melt without any residues that could impair the melt bath. Thus, there is no packaging refuse.
In another embodiment of the invention, a longitudinal cutting assembly and a transverse cutting assembly are assigned to the conveying path of the melt portions in the conveying direction behind the twin belt cooler. Thus, it is possible to separate the different rows of melt portions by isolating the respective melt portions.
In another embodiment of the invention, a matrix-shaped grid mask that can travel with the conveyor belt is assigned to the conveyor belt, which grid mask covers at least a major part of the belt surface and at least the length of the conveying end of the belt. The individual matrix spaces of the grid mask border the melt portions on all sides, wherein the melt portions are given an individual shape. The grid mask can either be carried along as a separate net strip with the conveyor belt or it can be firmly connected with the surface of the conveyor belt, thus also resulting in the conveyor belt being carried along.
In another embodiment of the invention, the height of the grid mask is less than the height of the cooling gap defined by the twin belt cooler. This embodiment guarantees that part of the molten mass of each melt portion flows over the edges of each grid space within the twin belt cooler, thus causing a connection between the upper and the lower sheet strips by means of the overflowed molten mass, in particular in case of a melt adhesive, without the necessity of additional welding or connecting processes.
In another embodiment of the invention, a spray damper for applying a separating layer is assigned to both sheet strips such that the separating layer can be sprayed onto each belt surface facing each sheet strip and/or onto each corresponding belt surface. Thus, the sheet strips can be easily detached at the exit of the twin belt cooler and at the carrying side of the conveyor belt, respectively.
BRIEF DESCRIPTION OF THE FIGURES
Additional advantages and features of the invention ensue from the claims and from the following disclosure of preferred exemplary embodiments of the invention, which are depicted in the drawings as follows:
FIG. 1 schematically illustrates a first specific embodiment of a system according to the invention for the production and coating of melt portions having a twin belt cooler;
FIG. 2 is a top view of a conveyor belt at the level of an inlet region of the twin belt cooler according to FIG. 1;
FIG. 3 schematically illustrates an application device for melt portions onto the conveyor belt for the system according to FIG. 1 in the direction of the arrows III--III in FIG. 1;
FIG. 4 is an enlarged partial section IV from FIG. 3;
FIG. 5 is a section of the system according to FIG. 1 at the level of section line V--V in FIG. 1;
FIG. 6 is an enlarged partial section VI from FIG. 5;
FIG. 7 illustrates another specific embodiment of a system according to the invention for the production and coating of melt portions;
FIG. 8 is a top view of the conveyor belt of the system according to FIG. 7 at the level of an inlet region of a twin belt cooler of the system according to FIG. 7;
FIG. 9 is a view of an application device of the system according to FIG. 7 in the direction of arrows IX--IX of FIG. 7;
FIG. 10 is an enlarged partial section X of the drawing from FIG. 9;
FIG. 11 is a section through the system according to FIG. 7 at the level of an inlet region of a twin belt cooler along the section line XI--XI in FIG. 7, and;
FIG. 12 is an enlarged partial section XII of the inlet region from FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A system for fabricating a molten mass in defined melt portions of equal size and for coating these melt portions involves a twin belt cooler 1 as the central part of the system. An application region 2 that is disclosed in detail hereinafter is situated before the actual cooling region 3 of twin belt cooler 1. A delivery region 4 is situated in conveying direction F 1 , F 2 behind twin belt cooler 1 at cooling region 3. Twin belt cooler 1 is formed by a lower conveyor belt 11 and an upper conveyor belt 15. Lower conveyor belt 11 circulates endlessly around a heated feed roller 12 and a delivery roller 13 that is driven by a drive motor 14, wherein feed roller 12 is disposed at a distance before upper conveyor belt 15 and delivery roller 13 at a distance behind conveyor belt 15. The upper end or surface of belt 11 is disposed horizontally and forms a lower end or surface of the belt in cooling region 3 of twin belt cooler 1. Upper belt 15 circulates endlessly around a feeding roller 16 in conveying direction F 2 as well as around a delivery roller 17 that is driven by drive motor 18, wherein a lower end or surface of belt 15 forms the upper end or surface of the belt cooling region 3 of twin belt cooler 1, limiting it at the top. In cooling region 3, the ends or surfaces of the belts of conveyor belt 11 and of conveyor belt 15 facing each other run parallel to each other. Three cooling regions 20, 21, 22 are assigned to conveyor belt 11, the first of the cooling regions is disposed in application region 2 in front of cooling region 3. The two other cooling regions 21 and 22 adjoin in cooling region 3, e.g., in the cooling gap between conveyor belt 11 and belt 15 in the conveying direction.
In application region 2, a molten mass in form of a melt adhesive S is deposited on conveyor belt 11 in specified viscosity in defined melt adhesive portions SP each in rows of eight in equal distances by means of a feeder head 5 used as a portioning device (FIGS. 1 through 4). To be able to apply molten mass S with a specified viscosity by means of feeder head 5 onto conveyor belt 11, a fabrication device in the form of a heat transfer medium 6 is disposed in front of feeder head 5, wherein preheated molten mass S passes through said heat transfer medium 6. Molten mass S is fed into heat transfer medium 6 from a reservoir 9 equipped with a rabble 10 by means of a pump 7 that is driven by drive motor 8. In the exemplary embodiment shown, the portioning device in the form of feeder head 5 disposes a horizontal inlet for the molten mass S, wherein eight blades 32 are assigned to said inlet, which press appropriately defined melt portions through eight casting nozzles 33 onto conveyor belt 11 below. Melt adhesive portions SP are applied onto conveyor belt 11 in a hemispherical shape (see FIGS. 3 and 4) and in pasteurized condition. The rows of eight melt adhesive portions SP are arranged next to each other and cover most of the strip of conveyor belt 11, which is designed as a steel belt.
To prevent the melt adhesive portions SP from adhering to conveyor belt 11, which is preferably a steel belt, a polyethylene sheet strip 28 is fed into conveyor belt 11 in the region of feed roller 12 before applying melt adhesive portions SP, which sheet strip serves as a base for melt adhesive portion SP and which lies flat on the surface of conveyor belt 11. The width of sheet strip 28 approximately coincides with conveyor belt 11 and has at least the total width of the cross row of the eight melt portions SP. Sheet strip 28 is continuously pulled off from a storage roll 26, on which sheet strip 28 is wound up, which storage roll 26 is seated to be pivotable by means of bearings.
In an exemplary embodiment according to the invention, molten mass S has a melt point of approximately 180° C. The melt point of the polyethylene sheet of sheet strip 28 is approximately 110° C.
Since sheet strip 28 is the base for all melt adhesive portions SP that are deposited on conveyor belt 11 in application region 2, sheet strip 28 also represents the underside of a coating of melt adhesive portions SP. Water spray damper 29 is assigned to sheet strip 28 and feed roll 12 between the belt surface of conveyor belt 11 and sheet strip 28 as a separator, which water spray damper 29 moistens both the belt surface of belt 11 and the underside of sheet strip 28 with a mist. Besides its effect as a separator, the water spray also has the advantage of a cooling effect, wherein the water film between sheet strip 28 and the belt surface prevents the molten mass applied by feeder head 5 (the temperature of which during application is higher than the melt point of sheet strip 28) from causing the sheet strip 28 to melt. It is advantageous that the plastic material of sheet strip 28 be adjusted with regard to its melting points and the processing temperature of molten mass S so that the melting of sheet strip 28 due to the applied molten mass is prevented in any case. In addition, the plastic material of sheet strip 28 is chosen such that it cannot chemically react with molten mass S, which means that it does not impair the properties of molten mass S. Since sheet strip 28 does adhere to melt adhesive portions SP, but not to the belt surface of conveyor belt 11, sheet strip 28 including melt adhesive portions SP can be easily detached from the belt surface on the delivery side, as disclosed in detail hereafter.
A plastic sheet strip 30, preferably also made of polyethylene, is analogously fed into the belt surface of upper belt 15 of twin belt cooler 1. Plastic sheet strip 30 is wound up on storage roll 27, which is seated above feed roll 16 of belt 15 in a frame that is not shown to be seated such that it is pivotable. A separating layer in the form of a water spray is also applied by means of a water spray damper 31 between sheet strip 30 and the belt surface of belt 15. Water spray damper 31 exhibits a spray stream directed to the belt surface of belt 15 and another spray stream directed to the assigned surface of sheet strip 30. Other means of separating layers of course can be used instead of water spray dampers.
The cooling gap of cooling region 3 of twin belt cooler 1 between the ends or surfaces of belt 15 and facing conveyor belt 11 is defined by a calibration roll 19 situated at the level of feed roll 16, which calibration roll can be adjusted in any known manner. Due to the height of the cooling gap of cooling region 3 defined by the distance of calibration roll 19 to feed roll 16, melt adhesive portions SP are flattened while entering the cooling gap, according to FIG. 2, giving them a disc-shape with a larger diameter. The equal thickness of melt adhesive portions SP due to the calibration in the cooling crap, guarantees that the melt adhesive portions cool off equally by passing through cooling regions 21 and 22 within twin belt cooler 1. The shaping of melt adhesive portions SP by entering into the cooling gap of cooling region 3 at the level of calibration roll 19 is well recognizable by means of FIGS. 5 and 6. Since sheet strip 30 fits closely and evenly to the belt surface of belt 15 analogously to sheet strip 28, sheet strip 30 simultaneously forms the covering coat layer for melt adhesive portions SP conveyed through the cooling gap in cooling region 3. Thus, melt adhesive portions SP are lead through between two layers of sheet strips 28, 30 through cooling region 3. Two sheet strips 28 and 30 each adhere in the region of the surface and the underside of each melt adhesive portion SP onto the respective melt adhesive portion SP.
In order to achieve a detachment of the individual melt adhesive portions SP after passing through cooling region 3 and in order to achieve a complete coating by means of the sheet strip sections assigned to each melt adhesive portion SP, a longitudinal cutting assembly 23 and a transverse cutting assembly 24 are assigned to conveyor belt 11 in delivery region 4. Longitudinal cutting assembly 23 and transverse cutting assembly 24 serve as to separate longitudinal and transverse rows of melt adhesive portions SP, in that the two sheet strips are cut between the respective longitudinal and transverse rows. After passing through longitudinal and transverse cutting assemblies 23, 24, a double-sided sheet cut for each melt adhesive portion SP results, wherein the upper cut part is formed by an appropriate cut part of sheet strip 30 and the lower cut part is formed by an appropriate cut part of sheet strip 28. If the plastic material of the sheet strip already exhibits sufficient adhesive properties, it suffices to press the edges of the sheet cuts of each melt adhesive portion SP together, wherein the cut parts of each sheet cut facing each other connect to each other and embrace each melt adhesive portion SP on all sides. In addition, a welding device 25 is provided for this exemplary embodiment to achieve a secure connection of the upper and lower cut parts of the sheet cuts of the melt adhesive portions SP, which welding device welds tile edges of the sheet cuts on all sides around tile respective melt adhesive portion SP. In the disclosed exemplary embodiment, this welding device 25 is disposed behind the cutting assemblies in the conveying direction. The welding device can also be disposed in front of the cutting assemblies or it can be combined with the cutting assemblies by providing a resistance wire configuration, in that the resistance wire configuration undertakes both the welding and the connecting.
At the level of delivery roll 13, the isolated and packed, e.g., coated melt adhesive portions SP, can be detached from the belt surface of conveyor belt 11. Then they are assorted into appropriate units of quantity and packed. According to their future use, the melt adhesive portions can be directly transferred into an appropriate melt bath, wherein the sheet cuts melt on without hazardous residues, because the melt point of the melt adhesive portion is higher than the melt point of the sheet cuts.
The system according to FIGS. 7 through 12 corresponds in its essential functional units to the system according to FIGS. 1 through 6 disclosed in detail above, so that regarding identical functional units, reference is made to the disclosure of the exemplary embodiment according to FIGS. 1 through 6. Identical components and modular units of the system according to FIG. 7, are labeled with the same reference marks as for the system according to FIG. 1. The essential differences of the specific embodiment according to the invention according to FIGS. 7 through 12 are defined by a different shaping of melt adhesive portions SP, wherein the outwardly facing belt surface of the conveyor belt 11a exhibits a matrix-shaped grid mask 34. In the disclosed exemplary embodiment, grid mask 34 according to FIGS. 7 through 12 is connected with the belt surface of conveyor belt 11a on all sides and exhibits a grid pattern on all sides that consists of stays that are disposed longitudinally and transversely to conveying direction F 1 , F 2 . The longitudinal and transverse stays each form transverse rows of eight grid spaces--which are also called matrix spaces--arranged next to each other, into which one melt adhesive portion SP each can be applied by means of portioning device 5.
Sheet strip 28 is fed to conveyor belt 11a such that it rests on grid mask 34. By applying melt adhesive portions SP into the grid spaces, sheet strip 28 is pressed down onto the belt surface of conveyor belt 11a in these regions. At the same time, it covers, however, all stays of grid mask 34 (FIG. 10). The height of grid mask 34 is slightly lower than the height of the cooling gap within cooling region 3a of twin belt cooler 1a, which cooling cap is defined by the calibration roll 19. In application region 2a, melt adhesive portions SP are applied into the grid spaces of grid mask 34 in such volumes that melt adhesive portions SP protrude the stays of grid mask 34 (see FIGS. 9 and 10). The molten mass and the volume of each melt adhesive portion SP is adjusted to the respective grid space of grid mask 34 in a way that melt adhesive portions SP in the cooling gap (see FIGS. 11 and 12) completely fill out the respective grid space in grid mask 34 and that a certain portion of the molten mass of each melt adhesive portion SP extends over the edges of each grid space, defined by the stays, on all sides. Since upper sheet strip 30 travels into cooling region 3a together with belt 15 when entering the cooling gap, as in the exemplary embodiment according to FIGS. 1 through 6, upper sheet strip 30 forms the upper coating layer for melt adhesive portions SP. Due to the overflow of the molten mass of melt adhesive portions SP over the stays of grid mask 34 (FIG. 12), at the level of the longitudinal and transverse stays of grid mask 34, a patent, relatively thin melt film forms which--in the transition regions between individual melt adhesive portions SP--creates a connection between opposite sheet strips 28 and 30, because, in the region of this grid-shaped melt film, sheet strips 28 and 30 only adhere to the melt film along a small distance.
After cooling off melt adhesive portions SP in cooling region 3a, the continuous strip of melt adhesive portions SP and sheet strip 28, 30 covering melt adhesive portions SP can be detached from conveyor belt 11a and from grid mask 34 and can be transferred to a separate conveyor belt 35 in a delivery region 4a. Conveyor belt 35 also provides a circulating endless belt moving around a feed roll and a delivery roll, wherein the delivery roll is driven by a drive motor 36. Melt adhesive portion strip including adhering sheet strips 28 and 30 is now separated into the individual melt adhesive portions by means of longitudinal cutting assembly 23 and transverse cutting assembly 24, wherein the separation of longitudinal cutting assembly 23 and transverse cutting assembly 24 is each executed at the level of the grid-shaped melt film between melt adhesive portions SP. Because the sheet cuts formed in this manner are already connected to each other by the melt film along the edges of the separated melt adhesive portions on all sides and because the narrow open edges of the melt film do not have to be sealed additionally by appropriate sheet cuts, directly after separation of longitudinal cutting assembly 23 and transverse cutting assembly 24, the coated melt adhesive portion is prepared, without the necessity of additional melt processes of the sheet cuts.
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A method for producing and coating melt portions includes two sheet strips, which form coating material layers, being continually fed. The melt portions embedded between the sheet strips are cooled and calibrated according to their thickness. The sheet strips are longitudinally and transversely separated in the region of their connection points such that the melt portions become isolated and the sheet strips are connected to each other such that each melt portion is embraced tightly.
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BACKGROUND OF THE INVENTION
The present invention relates to therapeutic devices and, more particularly, to therapeutic devices for exercising immobilized limbs in order to reverse the effects of osteoporosis.
When human limbs are immobilized for prolonged periods of time, whether due to paralysis or to encasement in a cast, a condition known as osteoporosis can occur. Osteoporosis is a deossification with absolute decrease in bone tissue resulting in, among other things, structural weakness of the bone. Many therapies have been developed to slow down or reverse osteoporosis. For example, since it is well-known that human bones are sensitive to electric current, attempts have been made to utilize electric current to promote osteogenesis, or formation of bone.
Although osteogenesis can be stimulated by delivering electric current to bones by means of internal electrodes, there are disadvantages to this type of treatment. One disadvantage is that stimulation of bones by electric current has only a slight effect on increasing bone formation.
More recently, it has been found that the vibration of bones can reverse osteoporosis. This relationship has been found in bones which have been made osteoporatic by previous plaster cast immobilization, such as that used to treat a fracture of the leg bone. It is believed that the application of mechanical vibration to the limbs deforms the bones within the limbs and generates an endogenous electric current due to the piezo-electric effect of the bone matrix. Osteoporatic bones in the legs have been treated by the application of mechanical vibrations to the soles of the feet. A disadvantage with this type of treatment is that the transmission of vibrations through the bones of the legs tends to vibrate and hence build up the bones in a single plane or along one axis, to the exclusion of other bones or along other axes.
In a specific example, vibration applied to the lower leg vibrated the knee at a single angle and missed stressing many critical bone surfaces along the leg. Of course, the application of vibrations to the leg or other limb at a plurality of locations may counteract this disdvantage to some extent, but this would greatly lengthen the time and expense of the treatment.
Another problem encountered with this type of therapeutic treatment is that it is difficult to determine the magnitude of the vibrations actually felt by the bones of the legs receiving the vibrations. For example, if the mechanical vibration is applied to the bottom of the foot, the soft tissue in that area and in the knee absorb some of the vibration, so that it is not possible to determine the amplitude of vibration actually felt by the bone simply by measuring the amplitude of the vibration applied to the limb. This relationship between the applied vibration and the vibration actually felt by the bones renders conventional vibrators unacceptable for use in giving reproducible results in terms of knee and leg treatment.
Accordingly, there is a need for a therapeutic device which applies external mechanical vibrations to the limbs of a subject and thereby vibrates the bones of those limbs sufficiently to reverse the effects of osteoporosis. Furthermore, such a device should be designed to vibrate the bones of the subject's limbs in a number of planes so that all of the bone surfaces are vibrated sufficiently to reverse the effects of osteoporosis. In addition, the device should include means for detecting the resultant vibration of the bones of the subject's limbs so that the magnitude of the vibrations actually felt by the bones can be controlled.
SUMMARY OF THE INVENTION
The present invention was developed to provide a device for the vibration stimulation of the bones of immobilized limbs to reverse osteoporosis, in which the limbs are vibrated while in motion, so that the bones are built up in a plurality of planes and along a plurality of axes. Use of the invention not only reduces the treatment time required, but effects a more thorough reversal of osteoporosis than prior methods and devices. The present invention is a therapeutic device which comprises a crank assembly adapted to be attached to the distal ends of a pair of human limbs, such as the legs, a drive motor which is attached to the crank assembly to rotate the crank assembly so that the legs move in a circular pattern similar to pedaling a bicycle, a vibrator for vibrating the crank assembly while the legs are moving, and a control for generating power to regulate the magnitude of the driving vibrations generated by the vibrator. The pedal assembly, drive motor and vibrator are all mounted on a single frame which increases the stability and portability of the device.
In a preferred embodiment, the device includes an accelerometer which is adapted to be attached to one of the supported limbs of the human subject, preferably on a bone surface, so that it measures the active amplitude of the vibrations felt by the bones of the limbs attached to the device. The accelerometer generates a signal, proportional to the amplitude of these measured vibrations, and the signal is used to vary the magnitude of the electric current generated by the control to drive the vibrator, thereby forming a closed-loop system which regulates the amplitude of the driving vibrations. The control is adjusted such that the maximum amplitude of the vibrations felt by the bones of the subject stays within a predetermined range throughout the use of the device by the subject. The vibrations felt by the bones are sufficiently strong to reverse osteoporosis, but are below the level at which pathological damage is caused.
It should be understood that this device can be adapted relatively easily to perform the same therapeutic treatment upon the arms of a human subject, but this specification will discuss the invention in relation to treatment of the legs. To operate the device, the feet of the subject, are strapped to the crank assembly, and the motor is actuated to rotate the crank, thereby moving the feet in a circular pattern similar to a bicycle pedaling motion. While the legs are moving in this circular pattern, the vibrator generates vibrations which are transmitted to the crank assembly and through the assembly to the feet and legs of the subject. By rotating the legs in this circular pattern during the application of the vibrations, the bones of the legs, especially those in the vicinity of the knees, are vibrated in a variety of positions to ensure that all surfaces of the bones are adequately vibrated.
Accordingly, it is an object of the present invention to provide a therapeutic device for reversing osteoporosis in human limbs; a device in which the bones of the subject's limbs are vibrated by the application of external mechanical force while in motion to ensure that the bones are evenly vibrated; a device in which the amplitude of the vibrations felt by the subject's bones is measured and is used to control the driving vibrations applied to the limbs to maintain the effective amplitude below a predetermined maximum; and a device which vibrates the bones of the subject's limbs that is compact, portable and relatively inexpensive to manufacture, thereby making the device available to patients on a wide scale.
Other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat schematic, perspective view of a therapeutic device comprising a preferred embodiment of the invention;
FIG. 2 is a side elevation of the embodiment of FIG. 1, showing its use with a human subject;
FIG. 3 is a schematic diagram showing an accelerometer circuit for the accelerometer shown in FIG. 2;
FIG. 4 is a schematic diagram showing the vibrator feedback control of the embodiment shown in FIG. 2; and
FIG. 5 is a schematic diagram showing the vibrator controller circuit of the embodiment shown in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIGS. 1 and 2, the therapeutic device of the present invention includes a base 10, a frame 12 mounted on the base, a crank assembly 14 supported by the frame, a drive motor assembly 16 and a vibrator 18. The base 10 includes a base plate 20 which is supported at an angle to the horizontal by struts 22 (one of which is shown). Struts 22 elevate an upper end of the base plate 20 from a foundation plate 24. Although not shown, it is within the scope of the invention to provide a base plate 20 which can be adjusted relative to the foundation plate 24 to provide a variety of angles of inclination to the horizontal to suit a particular human subject.
The vibrator 18 preferably is a standard electromagnetic-coupled vibrator that requires an input on the order of about 12 volts to operate. An example of such a vibrator is the Model C31-1 vibrator manufactured by MB Manufacturing Co., Inc. of New Haven, Conn. The vibrator 18 is mounted on the base plate 20 by brackets 26, 28, which are attached to the base plate by machine screws 30.
The frame 12 includes a pair of tubes 32, 34 which are attached to the brackets 26, 28, preferably by welding, and extend upwardly from the plane of the base plate 20. A pair of rods 36, 38 are shaped to telescope within the tubes 32, 34, respectively, and are attached to the underside of a support plate 40.
The crank assembly 14 is similar in construction to the crank assembly of a conventional bicycle, and includes a bearing housing 42 which is welded to an upper surface of the support plate 40, and a crank 41, rotatably attached to the housing and including crank arms 44, 46 extending outwardly from the bearing housing, and pedals 48, 50 rotatably attached to the ends of the crank arms 44, 46, respectively. The pedals 48, 50 have straps 52, 54, which preferably are adjustable and include closures of the hook-and-loop type, to secure the feet 56, 58 of the legs 60, 62 of a human subject 64 to the pedals.
It is within the scope of the invention to provide straps (not shown) which are adapted to receive the hands of a human subject. The function of the straps in either case is to secure the distal ends of the limbs it is desired to treat, so that the limbs remain engaged with the pedals even though the human subject 64 has lost control of the limbs due to a trauma, disease, or congenital defect. The crank assembly 14 includes a driven sprocket 66 which engages an endless sprocket chain 68 that is attached to the motor assembly 16.
Bracket 28 includes an upper arm 70 that supports a variable speed electric motor 72 comprising the motor assembly 16. The output shaft 74 of the motor 72 is attached to a drive sprocket 76 which engages the sprocket chain 68. Rotational movement of the drive sprocket 76 is transmitted by the sprocket chain 68 to the driven sprocket 66 to rotate the crank arms 44, 46 and pedals 48, 50 in a circular path.
The output shaft 78 of the vibrator 18 is connected by a rigid rod 80 to the support plate 40. The rod 80 is screwed to the plate 40 by nuts 81 which are threaded on an upper end of the rod above and below the plate. Vibration of the output shaft 78 is thereby transmitted through the rod 80 to the support plate 40 and to the crank assembly 14.
An accelerometer 82 is mounted on a strap 84 that is adapted to be fastened on the leg 60 of the subject 64. The strap 84 preferably includes a hook-and-loop type fastener so that it may be easily attached and removed from the leg 60. It is also preferable to attach the accelerometer 82 to the leg 60 near or over a bony protrusion such as the ankle bone so there is a minimum amount of skin between the accelerometer and the bone. The accelerometer 82 is connected to a control 86 by a wire 88, and the control is connected to the vibrator 18 by wire 90.
Due to energy losses and the inherent attenuation qualities of human skin, the amplitude felt by the bones may be less than the magnitude of the vibrations measured at, for example, the crank 41. Furthermore, the amplitude felt will vary with the change in angular relation between the legs 60, 62 and the crank 41 as the crank is pedaled. By mounting the accelerometer 82 on the leg 60, the amplitude of the vibrations actually felt by the bones at all times is measured.
The accelerometer 82 is of a type well-known in the art and is shown schematically in FIG. 3. An appropriate accelerometer is the Model 7264-2000 manufactured by Endevco Corp. of San Juan Capistrano, Calif. The accelerometer circuit includes a bridge circuit, generally designated 92, which is connected to an operational amplifier 94 to produce a voltage that varies with the amount of acceleration applied to the accelerometer. The output of the accelerometer 82 is conducted to the control 86 through wire 88 to a vibrator feedback control circuit shown in FIG. 4.
The accelerometer output is amplified by operational amplifiers 96, 98 and halfwave rectified by diode 100 in combination with resistor 102 and capacitor 104. The signal passes through an inverting buffer 106 which consists of an operational amplifier 108 and an offset voltage input 110. The offset voltage input 110 is adjusted so that at zero acceleration, in which there is no signal from accelerometer 82, a predetermined maximum voltage is generated by the buffer 106, and at a maximum acceleration, zero voltage passes through the inverting buffer. The signal is then passed through a second buffer 112 which includes a transistor 114 and a variable resistor 116, the combination acting as an impedance shifter.
The output of the vibrator feedback control circuit is connected to the collector of a transistor 118 in a vibrator power circuit shown in FIG. 5. The vibrator power circuit includes a timer 120 which generates a square wave at a predetermined frequency. Experimentation has shown that a preferred frequency is between 10 and 40 hz. Frequencies much lower than 10 hz can create a resonant vibration in the knee, which has a natural frequency of about 6 hz, that would seriously damage the bones of the knee. Vibrations having a frequency higher than 40 hz have been found to cause pathological damage to the knee.
The square wave generated by timer 120 enters the base of the transistor 118. An alternate power source for the collector of transistor 118 is a 12 volt source 122 which can be varied to provide a constant voltage input. The square wave is then shaped to form a sine wave by a wave shaping component which includes an operational amplifier 124 connected as an integrator. The output of amplifier 124 is connected directly to the vibrator 18 by wire 90 (FIG. 2).
To operate the therapeutic device shown in FIGS. 1 and 2, the subject 64 is seated in a chair 126 of suitable height and the feet 56, 58 of the subject are strapped to the pedals 48, 50 of the crank assembly 14. The accelerometer 82 is strapped to the ankle of the leg 60 of the subject 64 at an appropriate location near a bone. The control 86 is actuated to power the vibrator 18 which transmits driving vibrations through the frame 12 and crank assembly 14 to the legs 60, 62 of the subject 64. The amplitude of the vibrations actually felt by the bones of the subject 64 is measured by the accelerometer 82, and a signal is generated which is used as an input in the feedback control circuit of FIG. 4. The output voltage at the buffer 112 is adjusted by adjusting the potentiometer 116 and/or voltage offset 110 to provide a predetermined voltage value for zero acceleration and a zero voltage output for a maximum desired acceleration. It has been found that a maximum vibration amplitude of between 10 g and 50 g, felt by the bones, is preferable.
The motor 16 is actuated to rotate the crank assembly 14, thereby causing the legs 60, 62 of the subject 64 to travel in a circular path simulating the riding of a bicycle. Since the angles at which the vibrations are transmitted to the legs vary as the legs move in the circular path, the amplitude of the driving vibration must constantly change to maintain the amplitude of the vibrations felt by the bones within the aforementioned range.
Accordingly, as the amplitude of the felt vibrations reaches the maximum value, the voltage generated by the feedback circuit drops to zero thereby decreasing the amplitude of the signal from the controller circuit of FIG. 4 to the vibrator 18, although the frequency of the square wave generated by the timer 120 remains constant. This acts to reduce the amplitude of the driving vibration transmitted by the vibrator to the frame 12 and crank assembly 14 and to the legs 60, 62.
Conversely, should the amplitude of the vibrations felt by the accelerometer 82 drop below a predetermined value, the voltage generated by the feedback control circuit shown in FIG. 4 increases to a maximum value, effecting an increase in the amplitude of the current driving the vibrator 18. As a result, the amplitude of the driving vibrations transmitted to the legs 60, 62 of the subject 64 remain substantially constant as the legs are moved in circular paths by the crank assembly 14, even though the angles at which the vibrations are transmitted from the crank assembly to the legs change constantly. Vibrations of the appropriate amplitude and frequency are, therefore, transmitted to the legs 60, 62 of the subject 64 throughout a range of motion so that all of the bone surfaces of the legs are properly vibrated, and the reversal of osteoporosis is effected in all of the bones of the legs.
Although FIGS. 3, 4 and 5 depict a single circuit for providing a feedback from the legs of the subject to control the amplitude of the driving vibrations generated by the vibrator, it should be understood that other equivalent circuits may be employed by those having skill in the art without departing from the scope of the invention. Similarly, the components of the circuits depicted in FIGS. 3, 4 and 5 may be changed without changing the function and operation of the circuits. Examples of typical components used in these circuits are set forth in the following table:
TABLE I______________________________________Reference No. Component Part No.______________________________________ 92 Accelerometer 7264-2000 94 Op. amp. 1458 96 Op. amp. 1458 98 Op. amp. 1458108 Op. amp. 1458114 Transistor 2N3904118 Transistor 2N3904120 Timer NE555124 Op. amp. 1458______________________________________
While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention.
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A therapeutic device for reversing osteoporosis in human limbs which comprises a crank assembly adapted to attach to the distal ends of a pair of human limbs such as the legs, a motor for rotating the crank assembly so that the limbs move along a predetermined path, a vibrator for vibrating the crank assembly, thereby transmitting vibrations to the limbs, and a control for regulating the amplitude of the vibrations transmitted to the limbs. In a preferred embodiment, the control includes an accelerometer adapted to be mounted on a supported limb to generate a signal proportional to the amplitude of the vibrations actually felt by the limbs. The signal is used to modify the amplitude of electric current generated by the control to power the vibrator such that the amplitude of driving vibrations generated by the vibrator is proportional to the amplitude of vibrations felt by the limbs so that the amount of vibration of the limbs is maintained within a predetermined range.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of woodworking. More specifically, the present invention is a system of lightweight real wood beams used as ornamentation on or in a structure.
BACKGROUND OF THE INVENTION
[0002] Currently, if an individual wishes to install real wood beams on a ceiling or other surface of a building, the individual must ensure that the building structure is capable of supporting the weight of the real wood beams. If the building is being newly built, there must be proper support structures included in the frame of the building. Additionally, if the building is pre-existing and the real wood beams are being added into the building, the individual must make sure that the proper support structures exist or that they are added to the building. This can be an expensive and time consuming process.
[0003] Various techniques have been disclosed in U.S. Pat. No. 3,890,415 (Hull), U.S. Pat. No. 3,277,624 (Cornell), U.S. Pat. No. 4,427,171 (Frederiksen), U.S. Pat. No. 4,470,234 (Rosner), U.S. Pat. No. 4,926,606 (Hanson), U.S. Pat. No. 4,718,213 (Butterfield), U.S. Pat. No. 4,875,311 (Meyers), U.S. Pat. No. 5,031,377 (Beckmann), U.S. Pat. No. 5,560,159 (Pennypacker), and U.S. Pat. No. 5,802,800 (Meyers) to overcome the problems with installing real wood beams in buildings. However, these disclosures suffer from one or more of the following disadvantages. First, the above patents use composite material such as Styrofoam, particle board, plastic, etc. instead of real wood to reduce the weight of the beams. This distracts from the aesthetic appeal of the beams and their overall quality. Second, because these beams are made of composite material, they are easily damaged. Third, the materials used to make these composite beams do not provide enough strength to support any other fixtures that an individual may want to hang from the beams.
[0004] As such, it is desirable to provide a light weight wood beam that can be hung from any surface without attaching it to the frame of the building. The present invention provides a hollow beam that is made of real wood, yet is light enough to be coupled to any building surface.
SUMMARY OF THE INVENTION
[0005] The present invention is a wood beam system that is light weight and easily attaches to any type of building surface. The wood beam system is created by coupling two or more wood beam pieces together and fastening the pieces to anchor plates that are attached to a surface of a building. One feature of the invention is that the wood beam pieces are constructed of real wood with a hollow center. Because the wood beam pieces are hollow, they are lightweight and easy to install, yet maintain the aesthetic appeal of real wood beams.
[0006] The wood beam system is comprised of a first beam piece, a second beam piece, and an anchor plate. The anchor plate is coupled to the surface of a building, and the first beam piece and the second beam piece are positioned over the anchor plate. The first beam piece and the second beam piece are coupled together and to the anchor plate such that the first beam piece and the second beam piece engage the building surface to which they are coupled.
[0007] The primary object of this invention is to provide a real wood beam system that will easily attach to any building surface.
[0008] A further object of this invention is to provide a real wood beam system that is light weight.
[0009] A still further object of the invention is to provide a real wood beam system that can support other fixtures.
[0010] A further object of the present invention is to provide a real wood beam system that has a hollow center where electrical wiring can be run.
[0011] The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its operation together with the additional object and advantages thereof will best be understood from the following description of the preferred embodiment of the wood beam system when read in conjunction with the accompanying drawings. Unless specifically noted, it is intended that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the applicable art or arts. If any other meaning is intended, the specification will specifically state that a special meaning is being applied to a word or phrase. Likewise, the use of the words “function” or “means” in the Description of Preferred Embodiments is not intended to indicate a desire to invoke the special provision of 35 U.S.C. §112, paragraph 6 to define the invention. To the contrary, if the provisions of 35 U.S.C. §112, paragraph 6 are sought to be invoked to define the invention(s), the claims will specifically state the phrases “means for” or “step for” and a function, without also reciting in such phrases any structure, material, or act in support of the function.
[0012] Moreover, even if the provisions of 35 U.S.C. §112, paragraph 6 are invoked to define the inventions, it is intended that the inventions not be limited only to the specific structure, material or acts that are described in the preferred embodiments, but in addition, include any and all structures, materials or acts that perform the claimed function, along with any and all known or later developed equivalent structures, materials, or acts for performing the claimed function.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows an end view of the preferred embodiment of the invention.
[0014] FIG. 2 shows a side view of the preferred embodiment of the invention.
[0015] FIG. 3 shows a top view of the joint between the first beam piece and the second beam piece in the preferred embodiment of the invention.
[0016] FIG. 4A shows a cross section end view of the beam system with an anchor plate coupled to a surface of a building structure.
[0017] FIG. 4B shows a cross section end view of the beam system coupled to the anchor plate and engaged to the surface of a building structure.
[0018] FIG. 5 shows a top view of two beam pieces coupled together in the preferred embodiment of the beam system.
[0019] FIG. 6 shows a side view of the preferred embodiment of the invention with straps covering the joints.
[0020] FIG. 7 shows a perspective view of a first beam piece of the preferred embodiment of the invention.
[0021] FIG. 8 shows a perspective view of a second beam piece of the preferred embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0022] FIG. 5 shows a top view of the preferred embodiment of the beam system 100 . As seen in FIGS. 4A , 4 B, and 5 , the beam system 100 comprises a first beam piece 200 , a second beam piece 300 , and an anchor plate 400 . These pieces combined together create the beam system 100 disclosed. Preferably, the first beam piece 200 and the second beam piece 300 are made of real wood and are coupled together, as shown in FIG. 3 , using a shiplap joint 210 at the connection point.
[0023] In the preferred embodiment of the invention, the first beam piece 200 further comprises a bottom plate 220 and two vertical plates 230 , as shown in FIGS. 5 and 7 . The bottom plate 220 has a first edge 223 and a second edge 225 that are mitered. The two vertical plates 230 both include a top edge 233 and a bottom edge 235 . Only the top edges 233 of the vertical plates 230 are mitered in the preferred embodiment. The first edge 223 of the bottom plate 220 is coupled to the top edge 233 of the first vertical plate 230 , and the second edge 225 of the bottom plate 220 is coupled to the top edge 233 of the second vertical plate 230 . The mitered edges 223 and 225 of the bottom plate 220 and the mitered edges 233 of the two vertical plates 230 allow the coupled edges to form a 90° angle such that a hollow box with three sides is formed as depicted in the cross-section views of FIGS. 1 , 4 A, and 4 B.
[0024] As seen in FIGS. 5 and 8 , the second beam piece 300 is constructed the same way as the first beam piece 300 . The bottom plate 320 has a first edge 323 and a second edge 325 that are mitered. The two vertical plates 330 both include a top edge 333 (not shown) and a bottom edge 335 . Only the top edges 333 (not shown) of the vertical plates 330 are mitered. The first edge 323 of the bottom plate 320 is coupled to the top edge 333 (not shown) of the first vertical plate 330 , and the second edge 325 of the bottom plate 320 is coupled to the top edge 333 (not shown) of the second vertical plate 330 . The mitered edges 323 and 325 of the bottom plate 320 and the mitered edges 333 (not shown) of the two vertical plates 330 allow the coupled edges to form a 90° angle such that a hollow box with three sides is formed as depicted in the cross section views of FIGS. 1 , 4 A, and 4 B. Further, in the preferred embodiment of the invention, the width of the bottom plate 220 and 320 is 8 inches and the width of the vertical plates 230 and 330 is 7½ inches. In an alternate embodiment, the width of the bottom plate 220 and 320 is 5½ inches and the width of the vertical plates 230 and 330 is 5½ inches.
[0025] Further, the first beam piece 200 has a first end 240 and a second end 245 . As seen in FIG. 7 , the first end 240 of the first beam piece 200 has a male dado 250 cut into the bottom plate 220 and the two vertical plates 230 . Additionally, the second end 245 of the first beam piece 200 has a female dado 255 cut into the bottom plate 220 and the two vertical plates 230 . Similarly, the second beam piece 300 has a first end 340 and a second end 345 , as seen in FIG. 8 . The first end 340 of the second beam piece 300 has a male dado 350 cut into the bottom plate 320 and the two vertical plates 330 . Moreover, the second end 345 of the second beam piece 300 has a female dado 355 cut into the bottom plate 320 and the two vertical plates 330 .
[0026] The male dado 250 of the first beam piece 200 is coupled to the female dado 355 of the second beam piece 300 as shown in FIGS. 3 and 5 . This arrangement forms the shiplap joint 210 . The shiplap joint 210 is preferred because it allows the beam pieces 200 and 300 to be coupled together on the same plane. Additionally, the beam pieces 200 and 300 overlap and can be further fastened together with glue, nails, etc. or a combination of these types of fasteners.
[0027] When installing the beam system 100 to the surface of a building 500 (usually a ceiling), first the length of the surface 500 must be determined so that the proper number of beam pieces 200 and 300 can be prepared. In the preferred embodiment, the first beam piece 200 and the second beam piece 300 are 48 inches (4 feet) long when coupled together. In order for the first beam piece 200 and second beam piece 300 to be the desired length when coupled together, the male dado 250 on the first beam piece 200 and the female dado 355 on the second beam piece 300 must be cut to the same length dimensions such that they perfectly overlap. In other words, the male dado 250 on the first beam piece 200 protrudes the same length that the female dado 255 on the second beam piece 300 is inset. Because each beam piece 200 and 300 has both a male dado 250 and 350 and female dado 255 and 355 , any amount of beam pieces can be coupled together to fit the dimensions of a specific building surface 500 . The beam pieces at the end of the length of the surface each have one end that is cut flat such that the flat end abuts the end of the surface. In other words, there is only one end with a female or male dado.
[0028] The anchor plate 400 , as shown in FIGS. 4A and 4B , fits inside the hollow box formed by the beam pieces 200 and 300 . The anchor plate 400 is preferably made of solid wood and is fastened into the surface of a building structure 500 as seen in FIGS. 4A and 4B . Because the beam system 100 is made of hollowed wood beam pieces 200 and 300 , and is therefore light weight, the anchor plate 400 can be fastened into any type of building surface 500 and still secure the beam system 100 . Specifically, it is not required that the anchor plate 400 be fastened into the frame of a building. As shown in FIGS. 4A and 4B , the anchor plate 400 can be fastened into drywall with drywall screws 410 .
[0029] The anchor plates 400 are placed along the building surface 500 where there will be an intersection point of a first beam piece 200 and second beam piece 300 . Preferably, the anchor plates 400 are fastened into the ceiling with fasteners such as screws or drywall anchors. Once the anchor plates 400 are in place, the first end 240 of the first beam piece 200 is positioned over the anchor plate 400 such that the male dado 250 is over the anchor plate 400 and the bottom edges 235 of the vertical plates 230 engage the ceiling surface 500 . The second end 345 of the second beam piece 300 is also positioned over the anchor plate 400 such that the female dado 355 is fitted to the male dado 250 of the first beam piece 200 and the bottom edges 335 of the vertical plates 330 engage the ceiling surface 500 . Thus, the shiplap joint 210 is created. The first and second beam pieces 200 and 300 are then fastened together with nails. This process is continued across the length of the ceiling.
[0030] During the installation process, wiring can be run through the beam pieces 200 and 300 for fixtures, speakers, alarm systems, etc. Because the beam pieces 200 and 300 are hollow, it is easy to hide wiring for additional fixtures along the ceiling surface 500 . Moreover, fixtures, such as ceiling fans, lighting, etc., can be safely hung from the installed beam pieces 200 and 300 because the anchor plates 400 provide adequate support for additional fixtures.
[0031] Once all of the beam pieces are in place, pre-cut straps 600 , as seen in FIG. 6 , are wrapped around the joints for added aesthetic value. It is preferred that the straps 600 are made of leather and further fitted with decorative clavos 610 as seen in FIG. 6 .
[0032] The preferred embodiment of the invention is described in the Description of Preferred Embodiments. While these descriptions directly describe the one embodiment, it is understood that those skilled in the art may conceive modifications and/or variations to the specific embodiments shown and described herein. Any such modifications or variations that fall within the purview of this description are intended to be included therein as well. Unless specifically noted, it is the intention of the inventor that the words and phrases in the specification and claims be given the ordinary and accustomed meanings to those of ordinary skill in the applicable art(s). The foregoing description of a preferred embodiment and best mode of the invention known to the applicant at the time of filing the application has been presented and is intended for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in the light of the above teachings. The embodiment was chosen and described in order to best explain the principles of the invention and its practical application and to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
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The present invention is a light weight decorative wood beam system. The wood beam system is comprised of at least two wood beam pieces. The wood beam pieces each have a bottom plate and two vertical plates that form a three-sided, hollow box. Each wood beam piece comprises an end with a male dado and an end with a female dado. The male and female dado ends fit over each other to create a shiplap joint. Anchor plates are fastened into a building surface and support the wood beam system. Because the wood beam system is light weight, it does not require a special anchoring system to support the real wood beams.
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CROSS REFERENCE TO RELATED APPLICATIONS
Not applicable
REFERENCE REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
SEQUENTIAL LISTING
Not applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for testing a heat detector. More specifically, the present invention relates to a device for testing heat detectors that are located at various locations including those within a user's reach and those high above the floor, such that they cannot be easily reached.
2. Description of the Background of the Invention
Various types of heat detectors exist on the market including those that measure a fixed temperature and those that measure the rate of temperature rise. Fixed temperature heat detectors are designed to activate a visual and/or audible alarm after a fixed temperature is reached during a slow heat rise. Rate of rise heat detectors, on the other hand, sense rapid changes in the temperature in the surrounding air and when a certain change threshold is met will activate an alarm. Although fixed temperature and rate of temperature rise heat detectors can be installed as separate devices, they are also available in a single device. In addition, heat detectors come in myriad sizes and shapes. Some heat detectors exhibit a more traditional semi-circular shape and, when mounted, hang close to the ceiling or wall, while other heat detectors are more rectangular in shape and hang down from the ceiling when mounted.
Each type and style of heat detector has a range of effectiveness associated with it; therefore, large buildings such as warehouses and factories require multiple heat detectors. To ensure the safety of workers, goods, and equipment, heat detectors need to be tested regularly, efficiently, and accurately. A device for testing a heat detector should therefore be lightweight, durable, adaptable, reliable, easy to use, and provide necessary information to its operator or user.
The present invention seeks to improve upon the prior art through the use of an improved design for a device for testing heat detectors that enables efficient testing by providing a portable, lightweight device that can be used to test heat detectors of varying shapes, sizes, and locations and by providing a read out that can be recorded to check that the heat detector that is being tested has functioned properly.
SUMMARY OF THE INVENTION
In one aspect of the invention, a device for testing a heat detector is disclosed. The device comprises a housing shaped to receive a heat detector. A heating element is carried by the housing, and a fan is located proximate to the heater and adapted to activate the heat detector by increasing a temperature around the heat detector. The device also comprises a temperature device that is carried by the housing that measures the temperature near the heat detector. Furthermore, a display is attached to the housing that shows a value that relates to the temperature.
In another aspect of the invention, a device for testing a heat detector is disclosed. The device comprises a housing shaped to receive a heat detector. A heating element is carried by the housing and adapted to activate the heat detector by increasing a temperature around the heat detector. A temperature device is also carried by the housing that measures the temperature near the heat detector. Additionally, a memory is carried by the housing for storing a value related to the temperature. The device further comprises a test switch carried by the housing, wherein a change of state of the test switch causes the value to be stored in the memory.
In a further aspect of the invention, a method of testing a heat detector using a device is disclosed. The device comprises a housing shaped to receive a heat detector, a heating element carried by the housing and adapted to activate the heat detector by increasing a temperature around the heat detector, a temperature device carried by the housing that measures the temperature near the heat detector, a display attached to the housing that shows a value that relates to the temperature, a start switch carried by the housing, and a test switch carried by the housing, wherein a change of state of the test switch freezes the value shown on the display. The method comprises the step of moving the device toward the heat detector to be tested until a testing position is reached, wherein the housing of the device substantially surrounds the heat detector in the testing position and wherein the heating element is activated by the start switch upon contact of the start switch with an object. The method also comprises the step of maintaining the device in the testing position until the heat detector is activated. The method further comprises the step of moving the housing away from the heat detector once the heat detector is activated to change the state of the test switch, whereby changing the state of the test switch freezes the value shown on the display.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a device for testing a heat detector;
FIG. 2 is a top view of the device of FIG. 1 ;
FIG. 3 is a front view of the device of FIG. 1 , with the device in an extended position;
FIG. 4 is a bottom and back slanted view of the device of FIG. 1 ;
FIG. 5 is a left side elevational view of the device of FIG. 1 ; the right side being essentially a mirror image thereof; and
FIG. 6 is a cross-sectional view of the device along the lines 6 - 6 of FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, a device 10 for testing a heat detector is shown in FIG. 1 . The device 10 includes a housing 12 , which is comprised of a testing chamber 14 , a body 16 , battery compartments 18 a and 18 b , and a base 20 . Also shown in FIG. 1 is a handle 22 , which is connected to the body 16 .
As shown in FIG. 1 and FIG. 3 , the testing chamber 14 comprises a cup 24 , which is frusto-conical in shape, and a cylindrical neck 26 . The testing chamber 14 is attached to the body 16 via the neck 26 . The cup 24 and the neck 26 guide the device 10 over the heat detector being tested to an optimal testing position, in which the testing chamber 14 surrounds the heat detector creating a close-fit between the heat detector being tested and the testing chamber 14 . In a preferred embodiment, the cup 24 and the neck 26 can be made of a durable, transparent material to enable a user to observe the heat detector during testing and see any visual alarms associated with the heat detector. Optionally, the cup 24 and the neck 26 can be made from a durable, non-transparent material. The testing chamber 14 also includes a removable lid 28 , which is attached to the upper edge of the cup 24 , distal to the neck 26 . The lid 28 is placed on the device 10 when heat detectors of a smaller diameter are to be tested. When heat detectors having a larger diameter are to be tested, the lid 28 can be removed. It is preferred that the lid 28 is made of a flexible, heat resistant, non-conductive material such as silicone rubber or Santoprene® so that a firm seal can be created around the heat detector without the user having to exert a lot of pressure to the device 10 . A firm seal is important to prevent the loss of heat generated by the device 10 during testing.
The body 16 of the device 10 comprises an upper section 30 and a lower section 32 . The upper section 30 is generally cylindrical in shape and the lower section 32 is generally rectangular in shape although any shape can be used so long as the body 16 and the neck 26 have similar shapes. The body 16 is hollow and suitably sized to carry the neck 26 of the testing chamber 14 , as well as a heating element 34 and a fan 36 (shown in FIG. 6 ), both of which will be discussed in more detail below. The body 16 is preferably constructed from a durable, light-weight, heat resistant, and non-conductive material such as nylon, polypropylene, or acrylonitrile butadiene styrene.
The upper section 30 has an inner surface (not shown). Protrusions 38 provided on the neck 26 create a friction fit with the inner surface of the upper section 30 . The friction fit of the protrusions 38 and the inner surface of the upper section 30 is such that the testing chamber 14 is able to slide from a compact position as shown in FIG. 1 to an extended position as shown in FIG. 3 and vice versa. In addition, between each of the protrusions 38 are channels 40 . The channels 40 enable room-temperature air and excess heat to escape the device 10 during use. Furthermore, a stopping mechanism (not shown) may be provided such as a ledge on the inner side of the upper section 30 and an annular protrusion (not shown) on the bottom of the neck 26 to prevent the neck 26 from being removed from the body 16 . An adjustable height of the testing chamber 14 is desirable in order to allow for the testing of both traditional and pencil style heat detectors. The upper section 30 also includes a front side 42 , which contains an elongated aperture 44 . An adjuster slide 46 , which is carried by the neck 26 , fits within the elongated aperture 44 . The adjustor slide 46 enables a user to select between the compact or extended positions, by moving the adjustor slide 46 along the elongated aperture 44 . It is preferable that the adjustor slide 46 contain a mechanical clicking mechanism that enables the neck 26 to be held in place at various points along the elongated aperture 44 to accommodated heat detectors of varying heights. Although a manual adjustor slide is discussed an electronic switch is also contemplated.
In one embodiment as best shown in FIG. 3 , the elongated aperture 44 has an upside-down L-shape. In this embodiment, the adjuster slide 46 is moved vertically up the elongated aperture 44 and then pushed to the side to lock the neck 26 in the extended position. Optionally, a second elongated aperture 44 a and a second adjuster slide 46 a also may be included on a back side 48 of the neck 26 as shown in FIG. 4 , to provide added stability and support to the testing chamber 14 when in the extended position.
The upper section 30 further includes ears 50 a and 50 b . The ears 50 a , 50 b are located on corresponding left and right sides 52 a and 52 b , respectively, of the upper section 30 . The handle 22 is attached to the ears 50 a , 50 b with pins 54 a and 54 b (shown in FIG. 6 ) and extends behind the back side 48 of the upper section 30 . The pins 54 a , 54 b can be held in place by any suitable mechanical connection mechanism known to those skilled in the art. The housing 12 is movable about a horizontal axis that extends through the midpoints of the ears 50 a and 50 b , thus enabling the housing 12 to be positioned in numerous locations relative to the handle 22 .
As best seen in FIG. 2 and FIG. 5 , the handle 22 comprises a U-shaped portion 56 and a connection tail 58 . The connection tail 58 is attached to the U-shaped portion 56 at a midpoint 60 . In one embodiment, the lower part of the U-shaped portion 56 and the connection tail 58 may be positioned at a downward angle of approximately 135 degrees from the upper part of the U-shaped portion 56 . The angle and shape of the handle, however, may vary or contain a hinge. In addition, it is preferred that the U-shaped portion 56 be large enough to allow the housing 12 to pass through it as the housing 12 is rotated relative to the handle 22 to enable the testing of heat detectors positioned horizontally, vertically, or at an angle. Furthermore, it is also preferable that the housing 12 be able to lock at a specific position relative to the handle 22 . This can be accomplished by including a locking mechanism, ratchet mechanism, or rotary damper. An extension device 62 may be attached to the handle 22 through the connection tail 58 to enable a user to test heat detectors that are in a remote location, e.g., out of reach of the user. The extension device 62 is ideally made out of a lightweight, non-conductive material such as fiberglass and adjustable to enable a user to test heat detectors at varying heights from the floor.
Turning to FIG. 3 and FIG. 4 , the lower section 32 comprises left and right portions 64 a and 64 b , respectively. Attached to the left and right portions 64 a , 64 b are the battery compartments 18 a and 18 b , which house standard sized batteries. The battery compartment 18 a is attached to the left portion 64 a and the battery compartment 18 b is attached to the right portion 64 b . The battery compartments 18 a , 18 b also comprise battery base portions 66 a and 66 b , respectfully. By including the power source (i.e., batteries) for the device 10 within the housing 12 provides for more efficient testing of heat detectors. First, it eliminates the need for a power outlet and the use of electrical wires or cables that are heavy and burdensome. Second, it enables the device 10 to be quickly mounted on different extension devices for the testing of heat detectors at varying heights and locations. Furthermore, although two battery compartments are provided, the device 10 only requires one battery to operate. The use of a single battery reduces the weight of the device 10 , thereby further improving the efficiency of testing high mounted detectors.
Attached to the battery base portions 66 a , 66 b , and an underside portion 68 of the body 16 is the base 20 . In one embodiment, the base 20 has a generally recta-cylindrical shape and is constructed from material similar to or the same as that used for the body 16 . On a bottom 70 of the base 20 are a display 72 , power switch 74 , mode switches 76 a , 76 b , 76 c , and a test start button 78 . The display 72 includes one or more light emitting diodes or LEDs, which are connected by any suitable electronics known by those skilled in the art. LEDs that correspond with the mode switches 76 a , 76 b , 76 c may also be included to provide the user with a visual indication as to which mode they have selected. The display 72 provides the user with the measurement of the temperature taken by a temperature device 80 (shown in FIG. 2 ), which is preferably housed within the body 16 . The temperature device 80 can be an infrared thermometer, thermocouple, or other suitable temperature measuring device. The ability to display the temperature measurement while testing is critical in determining whether the heat detector is operating properly. In addition, the location of the display 72 on the bottom 70 of the base 20 enables the user to observe the temperature measurements displayed during testing. The display 72 may also provide the user with additional information including battery life, type of test being performed, e.g., rate to rise/fixed temperature or high/low temperature test, the date, and time.
The power switch 74 turns the device 10 on and off. When the power switch 74 is activated, power is provided to the display 72 , the mode switches 76 a , 76 b , 76 c , the test start button 78 , the temperature device 80 , and the various LEDs and electronics contained within the device. The test start button 78 is pressed by a user before a test is conducted to clear the information from a previous test shown on the display and/or stored in a memory 82 , which is discussed in more detail below. In addition, the test start button 78 is connected to the heating element 34 and the fan 36 via a control board 83 (shown in FIG. 6 ) and, upon actuation of the test start button 78 , power is provided to the heating element 34 , the fan 36 , and a start switch 86 (shown in FIGS. 1 and 6 ).
The mode switches 76 a , 76 b , 76 c enables the user to select a testing mode of the device 10 . Mode switch 76 a allows a user to choose between a fixed temperature test mode and a rate of temperature rise test mode. Mode switch 76 b enables a user to select whether the test is to be performed at a high or low temperature, and mode switch 76 c enables a user to choose the desired temperature unit, i.e., Fahrenheit (F) or Celsius (C), at which the test is to be performed and displayed. The ability to selectively choose between a fixed temperature and rate of temperature rise test is advantageous because it eliminates the need for multiple heat detector testing devices. Rather than having to switch between two different devices, a user can use one device, device 10 , to test two different types of heat detectors or to test two different functions within one heat detector, thereby saving time and money. In addition, the ability to select a high or low temperature test is desirable because it enables two different categories of heat detector to be tested—one category grouped around 135 degrees F. and one category grouped around 200 degrees F. Although multiple mode switches are discussed, a single multi-mode switch can be used. Furthermore, in lieu of separate mode and power switches, the device 10 may contain a single, combined power/mode switch.
When a fixed temperature test is selected by the user, the control board 83 is programmed to monitor the temperature of the air around the heat detector and adjust power to the heating element 34 and the fan 36 to maintain a desired or maximum temperature for a period of time. For example, if a low temperature test is selected, the control board 83 will regulate the heating element 34 and the fan 36 such that when a maximum temperature of 150 degrees F. is reached, that temperature is maintained for approximately 20 seconds. Similarly, if a high temperature test is selected, the control board 83 will adjust the power to the heating element 34 and the fan 36 so that once a maximum temperature of 200 degrees F. is reached, it is maintained for several seconds. The ability to reach and maintain a maximum temperature is beneficial and an important improvement because some heat detectors do not actuate immediately, i.e., as soon as the air around the detector is heated to a specific temperature. Rather, some heat detectors require the heating of the entire heat detector itself before actuation will occur, which requires more time and exposure to the heated air. If the temperature is not monitored and the heating element 34 and the fan 36 are not regulated, the temperature of the heated air produced by the heating element and directed by the fan will continue to rise, which may cause internal and/or external portions of the heat detector to melt or become damaged in some way. Therefore, by programming the control board 83 to regulate the heating element 34 and the fan 36 such that a specific temperature is reached and maintained, damage to the internal and external portions of the heat detector can be prevented.
FIG. 6 is a cross-sectional view of the device 10 taken along the line 6 - 6 . Housed within the upper and lower sections 30 , 32 of the body 16 are the heating element 34 , the fan 36 , and a nozzle 85 . The heating element 34 may be a positive thermal coefficient (PCT) ceramic heating element, an open coil heater, or similar heating device. In one embodiment, a PCT heating element is used such as a Cirrus 40/2 Fan Heater manufactured by DBK David+Baader GmbH.
The fan 36 is disposed on one side of the heating element 34 and the nozzle 85 is located on a different side. For example, as shown in FIG. 6 , the fan 36 may be located below the heating element 34 and the nozzle 85 may be located above the heating element 34 . When activated, the fan 36 blows air through the heating element 34 , which heats the air, and the nozzle 85 further directs the heated air at the heat detector being tested. The use of the fan 36 is important because it provides for efficient testing of the heat detector by blowing the heated air directly at the heat detector.
The start switch 86 may be disposed on an inner rim 87 of cup 24 as shown in FIGS. 1 and 6 , or attached to the exterior of the housing 12 . The start switch 86 may be a mechanical switch that is activated manually by the user by placing the device against a heat detector or surface such that the heat detector or surface changes the state of the start switch 86 by contact. The start switch 86 may also be a photoelectric eye or force sensing resistor. A photoelectric eye is activated upon a change in ambient light. A force sensing resistor is a device that exhibits a decrease in resistance with an increase in the force applied to an active surface, and acts as a switch when a threshold or “break force” is applied to the active surface.
In the preferred embodiment, the start switch 86 is a mechanical switch that requires physical contact to be activated. It is preferable that more than one start switch 86 be provided to ensure that activation occurs without the need for great accuracy when placing the device 10 up to the heat detector. In addition, springs 88 and an annular plate 90 (as best shown in FIG. 1 ) are also provided to assist in the activation of the start switch 86 . The springs 88 bias the annular plate such that the annular plate 90 remains in contact with the start switches 86 but does not trigger them. When pressure is applied to the annular plate 90 , the springs 88 depress and at least one start switch 86 is activated. Therefore, when the device 10 is held up to the heat detector, the start switch 86 is activated when it comes into physical contact via the annular plate 90 with the heat detector or a surface such as a ceiling or wall. Activation of start switch 86 , turns on the heating element 34 and fan 36 thereby commencing a test cycle. The heating element 34 generates heated air, which is directed by the fan 36 and nozzle 85 to the heat detector.
In order to protect against an inadvertent continuation of the test cycle, a test switch 84 is provided to determine if the test cycle should be continued. The test switch 84 may be located within the body 16 as shown in FIG. 6 and is connected to the heating element 34 , the fan 36 , and the power switch 74 via the control board 83 . In a preferred embodiment, the test switch 84 is an optical proximity switch, which senses the presence of the heat detector using a light transmitter and a receiver. Alternatively, the test switch 84 may be a sonar proximity switch, which sends and receives sound waves to detect the presence of the heat detector. In a further embodiment, the test switch 84 may be a solid state charge-coupled device (CCD) light sensing device with appropriate electronics to detect or identify an object at the opening of the test chamber 14 .
The test switch 84 determines if a heat detector is located within the testing chamber 14 of the device 10 approximately five seconds after the start switch 86 is actuated. If the test switch 84 confirms the presence of a heat detector, then the test switch 84 remains in a first state and the test cycle is continued. If a heat detector is not present, then the test switch 84 enters a second state. In the second state, the test switch 84 does not detect the physical presence of the heat detector and turns off the heating element 34 and the fan 36 thereby ending the test cycle. In one embodiment, a sound or light indicator (not shown) is included in the device 10 to inform the user that the test cycle has ended.
If the test switch 84 confirms the presence of a heat detector, the heating element 34 and fan 36 remain activated. The user maintains the device 10 in a testing position until the heat detector is activated. Once the heat detector is activated (i.e., an alarm is observed), the user moves the device 10 away from the heat detector. Moving the device 10 away from the heat detector causes the test switch 84 to enter the second state. When this occurs, the testing cycle is concluded, i.e., the heating element 34 and fan 36 are deactivated, and the temperature shown on the display 72 is frozen. Freezing the display 72 then enables the user to observe and record the temperature at which the heat detector was activated.
Alternatively, when the second state occurs, the temperature at which the heat detector is activated is recorded and stored in the memory 82 contained within the device 10 as shown in FIG. 6 . This may occur with or without a simultaneous freezing of the display 72 . The memory 82 may be a computer chip or other similar device for recording and storing the temperature reading at which the heat detector was activated and other pertinent information. As shown in FIG. 5 , the recorded and stored data can then be transmitted to a remote display 92 for further analysis through the use of a data transmitter 94 . The data transmitter 94 can be a wireless device such as Bluetooth, a removable drive, a wireless network, an optical data transmission device, or a standard computer connection such as a USB. The remote display 92 may be a LED display board, computer monitor, television monitor, or similar device. The remote display 92 may be attached to a computer, to the end of the extension device 62 , or to a handheld device carried by the user.
To test a heat detector that is located in a remote location with the device 10 , a user attaches the device 10 to the extension device 62 via the handle 22 . The user turns on the device 10 with the power switch 74 and uses the mode switches 76 a , 76 b , 76 c to select the appropriate testing modes. With the mode switches, the user selects the type of heat detector to be tested, i.e., rate of rise or fixed temperature, the temperature unit to be used and displayed, and whether a high temperature or low temperature test is to be conducted. The user may also adjust the height of the testing chamber 14 using the adjuster slide 46 depending on the size of the heat detector to be tested. After the appropriate height of the testing chamber and testing modes are selected, the user presses the start test button 78 , raises the device 10 to the heat detector being tested. The start switch 86 is activated when it comes into physical contact via the annular plate 90 with the heat detector or a surface upon which the heat detector is mounted. The heat detector is then moved closer to the heat detector until a testing position is reached. In the testing position, the testing chamber 14 surrounds and lies in close proximity to the heat detector and the lid 28 is pressed against the surface on which the heat detector is located.
When the start switch 86 is activated, it turns on the heating element 34 and the fan 36 . After five seconds the test switch 84 determines if a heat detector is present. If a heat detector is present, then the test switch 84 continues the test. The user maintains the device 10 in the testing position until the heat detector is activated. Once the heat detector is activated, the user moves the device 10 away from the heat detector; moving the device 10 away from the heat detector causes the test switch 84 to turn off the heating element 34 and the fan 36 and at the same time freeze the temperature shown on the display 72 and/or stores the temperature in the memory 82 . The user then lowers the device 10 and may record the temperature measurement shown on the display 72 .
INDUSTRIAL APPLICABILITY
Numerous modifications to the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications which come within the scope of the appended claims are reserved.
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This invention relates to a device for testing a heat detector. The device has a housing that is shaped to surround a heat detector and includes a heating element. A fan is located near the heating element and is adapted to activate the heat detector by increasing the temperature around the heat detector. The housing also includes a temperature device that measures the temperature near the heat detector. Furthermore, a display is attached to the housing to show the temperature around the heat detector during testing.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of and claims the benefit of priority of Japanese Patent Applications Nos. 2008-222723, 2008-222728, and No. 2009-165984, filed on Aug. 29, 2008, Aug. 29, 2008, and Jul. 14, 2009, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a film deposition apparatus and a film deposition method for depositing a film on a substrate by carrying out cycles of supplying in turn at least two source gases to the substrate in order to form a layer of a reaction product, and a computer readable storage medium storing a computer program for causing the film deposition apparatus to carry out the film deposition method.
[0004] 2. Description of the Related Art
[0005] As a film deposition technique in a semiconductor fabrication process, there is a technique in which a first reaction gas is adsorbed on a surface of a semiconductor wafer (referred to as a wafer hereinafter) under vacuum and then a second reaction gas is adsorbed on the surface of the wafer in order to form one or more atomic or molecular layers through reaction of the first and the second reaction gases on the surface of the wafer; and such an alternating adsorption of the gases is repeated plural times, thereby depositing a film on the wafer. This technique is referred to, for example, Atomic Layer Deposition (ALD) or Molecular Layer Deposition (MLD). This technique is advantageous in that the film thickness can be controlled at higher accuracy by the number of times alternately supplying the gases, and in that the deposited film can have excellent uniformity over the wafer. Therefore, this deposition method is thought to be promising as a film deposition technique that can address further miniaturization of semiconductor devices.
[0006] Such a film deposition method may be preferably used, for example, for depositing a dielectric material to be used as a gate insulator. When silicon dioxide (SiO 2 ) is deposited as the gate insulator, a bis(tertiary-butylamino)silane (BTBAS) gas or the like is used as a first reaction gas (source gas) and ozone gas or the like is used as a second gas (oxidation gas).
[0007] In order to carry out such a deposition method, use of a single-wafer deposition apparatus is being considered. The single-wafer deposition apparatus includes a vacuum chamber having a pedestal provided therein and a shower head placed at a top portion of the vacuum chamber facing the pedestal. With such a deposition method using the deposition apparatus, reaction gases are supplied from the shower head to a wafer placed on the pedestal, and unreacted gases and by-products are evacuated from a bottom portion of the chamber. In this case, when plural reaction gases are mixed inside the vacuum chamber, reaction products are generated. This results in the formation of particles. With this deposition apparatus, it is necessary to supply, for example, inert gas as purge gas to replace one reaction gas with another. Replacing of reaction gases takes a long time and the number of cycles may reach several hundred. This results in a problem of an extremely long process time. Therefore, a deposition method and apparatus that enable high throughput is desired.
[0008] Under these circumstances, use of an apparatus disclosed in Patent Documents 1-4 is being considered. In schematically describing this apparatus, the apparatus has a vacuum chamber including a pedestal for placing plural wafers arranged in a circumferential direction (rotation direction) and a gas supplying part being placed above the vacuum chamber facing the pedestal for supplying process gas to the wafers. The gas supplying part is arranged, for example, in plural areas in a circumferential direction so that they correspond to the arrangement of wafers on the pedestal.
[0009] In order to decompress the inside of the vacuum chamber having wafers placed on the pedestal at a predetermined process pressure, the pedestal and the plural gas supplying parts are relatively rotated around a vertical axis along with heating the wafers and supplying plural kinds of gases (the above-described first and second reaction gases) on the surface of the wafers from each of the gas supplying parts. Further, in order to prevent reaction gases from mixing inside the vacuum chamber, a process area formed by the first process gas and another process area formed by the second process gas are partitioned inside the vacuum chamber by providing physical partition walls between the gas supplying parts or forming a gas curtain with inert gas.
[0010] Accordingly, although plural kinds of gases are simultaneously supplied into the same vacuum chamber, because the process areas are partitioned for preventing reaction gases from mixing, the first and second reaction gases, from the standpoint of the rotating wafer, can be alternately supplied via the partition walls or the gas curtain. Therefore, a film deposition process is performed using the above-described method. Accordingly, benefits such as being able to perform film deposition in a short time owing to no need for gas replacement and being able to reduce the consumption amount of inert gas (e.g., purge gas) can be attained.
[0011] In introducing plural kinds of reaction gases into the same vacuum chamber, this apparatus not only needs to prevent the reaction gases from mixing with each other in the vacuum chamber but also needs to maintain a constant gas flow with respect to the wafers by strictly controlling the gas flow of the reaction gases in the vacuum chamber. In other words, because this apparatus has plural process areas formed in the vacuum chamber, turbulence of the gas flow to the wafers causes the size of the process areas, that is, the reaction time between the wafer and the reaction gases, to change. This may affect the quality of the thin film formed by the film deposition.
[0012] In a case where turbulence of gas flow of reaction gases inside the vacuum containers is caused in an in-plane part or a space between the surfaces of the wafers (e.g., a case where a necessary amount of reaction gas is not supplied to the wafers), there is a risk of the film thickness becoming reduced due to insufficient attraction of the reaction gases or degrading of film quality due to, for example, insufficient progress of an oxidation reaction. Further, in a case where reaction gases are mixed via the partition walls or the gas curtain due to turbulence of gas flow, reaction products are generated. The generation of the reaction products causes the formation of particles. Thus, although it is necessary to strictly control the gas flow of the reaction gases, the above-described partition walls or gas curtain is insufficient. Further, even in a case where there is a turbulence of gas flow during processing, such turbulence cannot be recognized.
[0013] Furthermore, because this apparatus processes the wafers while maintaining the inside of the vacuum chamber at a predetermined degree of vacuum (pressure), it is necessary to control both the degree of vacuum inside the vacuum chamber and the gas flow of the reaction gases in the vacuum chamber. Therefore, control of the gas flow is extremely difficult. Furthers because the degree of vacuum inside the vacuum chamber or the flow rate of the reaction gases changes according to the recipe of the process performed on the wafers, it is necessary to control the degree of vacuum or the gas flow of the reaction gases with respect to each recipe. This further makes the control difficult. Nevertheless, no consideration is made regarding the control of the gas flow in the above-described Patent Documents.
[0014] Patent Document 5 discloses a method of separating a vacuum chamber into a left-side area and a right-side area, forming a gas supply opening and an evacuation opening in each of the areas, supplying different gases in each of the areas, and evacuating gases from each of the areas. However, there is no mention regarding the gas flow inside the vacuum chamber, that is, regarding the flow rate of, for example, the gas evacuated from each evacuation opening. Therefore, even in a case where evacuation flow rate changes with time (e.g., due to accumulation of particles in the evacuation passage) and results in a loss of balance of the evacuation flow rate between the left and right areas (one side evacuation), such loss of balance cannot be recognized. Further, in a case where an evacuation pump is provided to each of plural evacuation channels, a difference of evacuation performance among the evacuation pumps may occur depending on the status of each evacuation pump. However, there is no mention in Patent Document 5 regarding such difference.
[0015] Furthermore, Patent Documents 6 through 8 disclose a film deposition apparatus preferably used for an Atomic Layer CVD method that causes plural gases to be alternately adsorbed on a target (a wafer). In this apparatus, a susceptor that holds the wafer is rotated, while source gases and purge gases are supplied to the susceptor from above. In this apparatus, a gas curtain is formed by inert gas, and the source gases and purge gases are separately evacuated from evacuation channels 30 a and 30 b. However, as with the Patent Document 5, there is no mention regarding the flow rate of the gas evacuated from each of the evacuation channels 30 a, 30 b.
[0016] Furthermore, there is known a method of providing an evacuation channel with a valve that can have its opening adjusted and estimating the flow rate of evacuation gas flowing in an evacuation channel from the opening of the valve. This method, however, does not measure the actual flow rate of evacuation gas. Therefore, the actual flow rate of evacuation cannot be recognized in a case where, for example, there is a change in the evacuation performance of the evacuation pump as described above.
[0017] Patent Document 1: U.S. Pat. No. 6,634,314
[0018] Patent Document 2: Japanese Patent Application Laid-Open Publication No. 2001-254181 (FIGS. 1, 2)
[0019] Patent Document 3: Japanese Patent Publication No. 3,144,664 (FIGS. 1, 2, claim 1)
[0020] Patent Document 4: Japanese Patent Application Laid-Open Publication No. H4-287912
[0021] Patent Document 5: U.S. Pat. No. 7,153,542 (FIGS. 6A, 6B)
[0022] Patent Document 6: Japanese Patent Application Laid-Open Publication No. 2007-247066 (paragraphs 0023 through 0025, 0058, FIGS. 12 and 18)
[0023] Patent Document 7: United States Patent Publication No. 2007-218701
[0024] Patent Document 8: United States Patent Publication No. 2007-218702
SUMMARY OF THE INVENTION
[0025] The present invention has been made in view of the above circumstances, and is directed to a film deposition apparatus, a film deposition method, and a computer-readable storage medium storing a computer program that causes the film deposition apparatus to carry out the film deposition method, which enable film deposition by alternately supplying plural reaction gases to a substrate in a vacuum chamber to produce plural layers of the reaction products of the reaction gases on the substrate and reduce the amount of separation gas supplied to separation areas provided along a circumferential direction of a rotation table on which the substrate is placed to separate a first process area to which a first reaction gas is supplied and a second process area to which a second reaction gas is supplied.
[0026] In order to achieve the above objective, a first aspect of the present invention provides a film deposition apparatus for depositing a film on a substrate by carrying out a cycle of alternately supplying at least two kinds of reaction gases that react with each other to the substrate to produce a layer of a reaction product in a chamber, the film deposition apparatus including: a rotation table provided in the chamber, the rotation table having a substrate receiving area for mounting the substrate thereon; a first reaction gas supplying part configured to supply a first reaction gas to one surface of the rotation table on which the substrate receiving area is provided; a second reaction gas supplying part configured to supply a second reaction gas to the one surface, the second reaction gas supplying part being separated from the first reaction gas supplying part along a circumferential direction of the rotation table; a separation area located along the circumferential direction between a first process area to which the first reaction gas is supplied and a second process area to which the second reaction gas is supplied, the separation area including a separation gas supplying part from which a separation gas is supplied; a first evacuation channel having an evacuation port between the first process area and the separation area; a second evacuation channel having an evacuation port between the second process area and the separation area; a first evacuation part connected to the first evacuation channel via a first valve; a second evacuation part connected to the second evacuation channel via a second valve; a first pressure detecting part interposed between the first valve and the first evacuation part; a second pressure detecting part interposed between the second valve and the second evacuation part; a process pressure detecting part provided in at least one of the first and second valves; and a control part configured to output a control signal for controlling opening of the first and second valves based on a pressure detection value detected from each of the first and second pressure detecting parts so that each of the pressure inside the chamber and the flow ratio between the gases flowing in the first and second evacuation channels becomes a predetermined value, respectively.
[0027] A second aspect of the present invention provides a film deposition apparatus for depositing a film on a substrate by carrying out a cycle of alternately supplying at least two kinds of reaction gases that react with each other to the substrate to produce a layer of a reaction product in a chamber, the film deposition apparatus including: a rotation table provided in the chamber, the rotation table having a substrate receiving area for mounting the substrate thereon; a first reaction gas supplying part configured to supply a first reaction gas to one surface of the rotation table on which the substrate receiving area is provided; a second reaction gas supplying part configured to supply a second reaction gas to the one surfacer the second reaction gas supplying part being separated from the first reaction gas supplying part along a circumferential direction of the rotation table; a separation area located along the circumferential direction between a first process area to which the first reaction gas is supplied and a second process area to which the second reaction gas is supplied, the separation area including a separation gas supplying part from which a separation gas is supplied; a first evacuation channel having an evacuation port between the first process area and the separation area; a second evacuation channel having an evacuation port between the second process area and the separation area; a first evacuation part connected to the first evacuation channel via a first valve; a second evacuation part connected to the second evacuation channel via a second valve; a first process pressure detecting part interposed between the first valve and the first evacuation part; a second process pressure detecting part interposed between the second valve and the second evacuation part; and a control part configured to output a control signal for controlling opening of the first and second valves based on a pressure detection value detected from each of the first and second pressure detecting parts so that each of the pressure inside the chamber and the pressure difference between the first and second process areas becomes a predetermined value, respectively.
[0028] A third aspect of the present invention provides a film deposition method for depositing a film on a substrate by carrying out a cycle of alternately supplying at least two kinds of reaction gases that react with each other to the substrate to produce a layer of a reaction product in a chamber, the film deposition method including the steps of: mounting the substrate substantially horizontally onto a rotation table provided inside the chamber; rotating the rotation table; supplying a first reaction gas to one surface of the rotation table on which a substrate receiving area is provided, from a first reaction gas supplying part; supplying a second reaction gas to the one surface from a second reaction gas supplying part, the second reaction gas supplying part being separated from the first reaction gas supplying part along a circumferential direction of the rotation table; supplying a separation gas from a separation gas supplying part provided in a separation area located between the first reaction gas supplying part and the second reaction gas supplying part; evacuating the first reaction gas of the first process area from a first evacuation part via a first evacuation channel having an evacuation port between the first process area and the separation area; evacuating the second reaction gas of the second process area from a second evacuation part via a second evacuation channel having an evacuation port between the second process area and the separation area; detecting the pressure inside the chamber, a first pressure between a first valve of the first evacuation channel and the first evacuation part, and a second pressure between a second valve of the second evacuation channel and the second evacuation port; and adjusting opening of the first and second valves based on pressure detection values detected in the detecting step so that each of the pressure inside the chamber and the flow ratio between the gases flowing in the first and second evacuation channels becomes a predetermined value, respectively.
[0029] A fourth aspect of the present invention provides a film deposition method for depositing a film on a substrate by carrying out a cycle of alternately supplying at least two kinds of reaction gases that react with each other to the substrate to produce a layer of a reaction product in a chamber, the film deposition method including the steps of: mounting the substrate substantially horizontally onto a rotation table provided inside the chamber; rotating the rotation table; supplying a first reaction gas to one surface of the rotation table on which a substrate receiving area is provided, from a first reaction gas supplying part; supplying a second reaction gas to the one surface from a second reaction gas supplying part, the second reaction gas supplying part being separated from the first reaction gas supplying part along a circumferential direction of the rotation table; supplying a separation gas from a separation gas supplying part provided in a separation area located between the first reaction gas supplying part and the second reaction gas supplying part; evacuating the first process area from a first evacuation part via a first evacuation channel having an evacuation port between the first process area and the separation area; evacuating the second process area from a second evacuation part via a second evacuation channel having an evacuation port between the second process area and the separation area; detecting a first pressure between a first valve of the first evacuation channel and the first evacuation part and a second pressure between a second valve of the second evacuation channel and the second evacuation port; and adjusting opening of the first and second valves based on pressure detection values detected in the detecting step so that each of the pressure inside the chamber and the pressure difference between the first process area and the second process area becomes a predetermined value, respectively.
[0030] A fifth aspect of the present invention provides a film deposition apparatus for depositing a film on a substrate by carrying out a cycle of alternately supplying at least two kinds of reaction gases that react with each other to the substrate to produce a layer of a reaction product in a chamber, the film deposition apparatus including: a rotation table provided in the chamber, the rotation table having a substrate receiving area for mounting the substrate thereon; a first reaction gas supplying part configured to supply a first reaction gas to one surface of the rotation table on which the substrate receiving area is provided; a second reaction gas supplying part configured to supply a second reaction gas to the one surface, the second reaction gas supplying part being separated from the first reaction gas supplying part along a circumferential direction of the rotation table; a separation area located along the circumferential direction between a first process area to which the first reaction gas is supplied and a second process area to which the second reaction gas is supplied, the separation area including a separation gas supplying part from which a separation gas is supplied; a ceiling surface located on both sides of the separation gas supplying part relative to a rotation direction for forming a narrow space between the rotation table and the ceiling surface for allowing the separation gas to flow from the separation area to the first and second process areas; a center portion area located at a center part of the chamber, the center portion area having an ejecting port for ejecting the separation gas to the one surface of the rotation table; a first evacuation channel having an evacuation port between the first process area and the separation area; a second evacuation channel having an evacuation port between the second process area and the separation area; a first evacuation part connected to the first evacuation channel; and a second evacuation part connected to the second evacuation channel.
[0031] A sixth aspect of the present invention provides a film deposition method for depositing a film on a substrate by carrying out a cycle of alternately supplying at least two kinds of reaction gases that react with each other to the substrate to produce a layer of a reaction product in a chamber, the film deposition method including the steps of: mounting the substrate substantially horizontally onto a rotation table provided inside the chamber; rotating the rotation table; supplying a first reaction gas to one surface of the rotation table on which a substrate receiving area is provided, from a first reaction gas supplying part; supplying a second reaction gas to the one surface from a second reaction gas supplying part, the second reaction gas supplying part being separated from the first reaction gas supplying part along a circumferential direction of the rotation table; supplying a separation gas from a separation gas supplying part provided in a separation area located between the first reaction gas supplying part and the second reaction gas supplying part; diffusing the separation gas in a narrow space between the rotation table and a ceiling surface provided on both sides of the separation gas supplying part in a manner facing the rotation table by supplying the separation gas from the separation gas supplying part provided in the separation area between the first and second reaction gas supplying parts; ejecting the separation gas to the one surface of the rotation table from an ejection port formed in a center portion area located at a center part of the chamber; evacuating the separation gas and the first reaction gas from the first process area and evacuating the separation gas and the second reaction gas from the second process area by evacuating the separation gas and the first reaction gas via a first evacuation channel having an evacuation port between the first process area and the separation area and evacuating the separation gas and the second reaction gas via a second evacuation channel having an evacuation port between the second process area and the separation area; evacuating the separation gas and the first reaction gas from a first evacuation part connected to the first evacuation channel; and evacuating the separation gas and the second reaction gas from a second evacuation part connected to the second evacuation channel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
[0033] FIG. 1 is a vertical cross-sectional diagram of a film deposition apparatus according to a first embodiment of the present invention;
[0034] FIG. 2 is a perspective view illustrating a configuration of the inside of a film deposition apparatus according to the first embodiment of the present invention;
[0035] FIG. 3 is a horizontal plan view of the film deposition apparatus according to the first embodiment of the present invention;
[0036] FIGS. 4A and 4B are vertical cross-sectional diagrams illustrating process areas and a separation area of the film deposition apparatus according to the first embodiment of the present invention;
[0037] FIG. 5 is a partial cross-sectional view of the film deposition apparatus according to the first embodiment of the present invention;
[0038] FIG. 6 is a fragmentary perspective view of the film deposition apparatus according to the first embodiment of the present invention;
[0039] FIG. 7 is a schematic diagram for describing the manner in which separation gas and purge gas flow in the film deposition apparatus according to the first embodiment of the present invention;
[0040] FIG. 8 is a fragmentary perspective view of the film deposition apparatus according to the first embodiment of the present invention;
[0041] FIG. 9 is a schematic diagram illustrating an example of a control part of the film deposition apparatus according to the first embodiment of the present invention;
[0042] FIG. 10 is a flowchart illustrating an example of an overall operation performed by the film deposition apparatus according to the first embodiment of the present invention;
[0043] FIG. 11 is a flowchart illustrating an example in a case of adjusting an evacuation flow rate with the film deposition apparatus according to the first embodiment of the present invention;
[0044] FIGS. 12A-12C are schematic diagrams illustrating, for example, the flow rate of gas flowing in the evacuation channels of the film deposition apparatus according to the first embodiment of the present invention;
[0045] FIG. 13 is a schematic diagram illustrating a state of adjusting the flow rate of gas flowing in the evacuation channels of the film deposition apparatus according to the first embodiment of the present invention;
[0046] FIGS. 14A and 14B is a schematic diagram illustrating, for example, the pressure in a chamber in a middle of an operation according to the first embodiment of the present invention;
[0047] FIG. 15 is a schematic diagram for describing a state where first and second reaction gases are separated by separation gases and evacuated according to the first embodiment of the present invention;
[0048] FIG. 16 is a schematic diagram illustrating an example of a film deposition apparatus according to a second embodiment of the present invention;
[0049] FIG. 17 is a flowchart illustrating an example in a case of adjusting an evacuation flow rate with the film deposition apparatus according to the second embodiment of the present invention;
[0050] FIG. 18 is a schematic diagram illustrating another example of the film deposition apparatus according to the second embodiment of the present invention;
[0051] FIGS. 19A and 19B are schematic diagrams for describing measurements of a convex portion used as a separation area according to the second embodiment of the present invention;
[0052] FIG. 20 is a vertical cross-sectional view illustrating another example of a separation area according to the second embodiment of the present invention;
[0053] FIGS. 21A-21C are vertical cross-sectional views illustrating another example of a convex portion used as a separation area according to the second embodiment of the present invention;
[0054] FIG. 22 is a horizontal cross-sectional view illustrating a film deposition apparatus according to an embodiment of the present invention;
[0055] FIG. 23 is a horizontal cross-sectional view illustrating a film deposition apparatus according to an embodiment of the present invention;
[0056] FIG. 24 is a perspective view illustrating a configuration of the inside of a film deposition apparatus according to an embodiment of the present invention;
[0057] FIG. 25 is a horizontal cross-sectional view illustrating a film deposition apparatus according to an embodiment of the present invention;
[0058] FIG. 26 is a vertical cross-sectional view illustrating a film deposition apparatus according to an embodiment of the present invention;
[0059] FIG. 27 is a plan view illustrating an example of a substrate processing system using a film deposition apparatus of the present invention;
[0060] FIG. 28 is a vertical cross-sectional view illustrating a film deposition apparatus according to another embodiment of the present invention;
[0061] FIG. 29 is a schematic diagram illustrating an example of a control part of the film deposition apparatus according to another embodiment of the present invention;
[0062] FIG. 30 is a flowchart illustrating an example of an overall operation performed on a substrate according to another embodiment of the present invention;
[0063] FIG. 31 is a flowchart illustrating an example of an overall operation performed on a substrate according to another embodiment of the present invention;
[0064] FIG. 32 is a vertical cross-sectional diagram taken along line I-I′ of FIG. 34 illustrating a film deposition apparatus according to a third embodiment of the present invention;
[0065] FIG. 33 is a perspective view illustrating a configuration of the inside of the film deposition apparatus according to the third embodiment of the present invention;
[0066] FIG. 34 is a horizontal cross-sectional plan view of the film deposition apparatus according to the third embodiment of the present invention;
[0067] FIGS. 35A and 35B are vertical cross-sectional views illustrating process areas and a separation area of the film deposition apparatus according to the third embodiment of the present invention;
[0068] FIG. 36 is a vertical cross-sectional view of a separation area of the film deposition apparatus according to the third embodiment of the present invention;
[0069] FIG. 37 is a perspective view of a reaction gas nozzle of the film deposition apparatus according to the third embodiment of the present invention;
[0070] FIG. 38 is a schematic diagram for describing a state where separation gas or purge gas flows in the film deposition apparatus according to the third embodiment of the present invention;
[0071] FIG. 39 is a fragmentary perspective view of the film deposition apparatus according to the third embodiment of the present invention;
[0072] FIG. 40 is a horizontal plan view illustrating a state where evacuation systems are provided to the film deposition apparatus according to the third embodiment of the present invention;
[0073] FIG. 41 is a schematic diagram for describing a state where first and second reaction gases are separated by separation gases and evacuated according to the third embodiment of the present invention;
[0074] FIG. 42 is a horizontal cross-sectional plan view illustrating a modified example of the film deposition apparatus according to the third embodiment of the present invention;
[0075] FIGS. 43A and 43B are schematic diagrams for describing measurements of a convex portion used as a separation area according to the third embodiment of the present invention;
[0076] FIG. 44 is a horizontal schematic diagram illustrating a film deposition apparatus according to another embodiment of the present invention;
[0077] FIG. 45 is a horizontal cross-sectional plan view illustrating a film deposition apparatus according to another embodiment of the present invention;
[0078] FIG. 46 is a vertical cross-sectional view illustrating a film deposition apparatus according to another embodiment of the present invention; and
[0079] FIG. 47 is a schematic plan view illustrating another example of a substrate processing system using a film deposition apparatus of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0080] Non-limiting, exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. In the drawings, the same or corresponding reference marks are given to the same or corresponding members or components. It is noted that the drawings are illustrative of the invention, and there is no intention to indicate scale or relative proportions among the members or components, alone or therebetween. Therefore, the specific thickness or size should be determined by a person having ordinary skill in the art in view of the following non-limiting embodiments.
[0081] According to the below-described embodiments of the present invention, process areas for processing plural reaction gases, which react with each other, are formed in the same vacuum chamber along a rotation direction of a rotation table. In performing thin film deposition by forming plural layers of a reaction product in the plural process areas by alternately passing a substrate through the plural process areas by using the rotation table, separation areas for supplying separation gas are provided between the process areas along with providing first and second evacuation channels with evacuation openings for separately evacuating the different reaction gases. Further, valves provided to each of the evacuation channels are adjusted so that the pressure in the vacuum chamber becomes a predetermined value, and the flow rate of the gas evacuated from each evacuation channel or the pressure difference between the process areas becomes a predetermined value. Accordingly, a suitable gas flow can be stably provided in both sides of the separation areas. Thus, because the gas flow of reaction gases on the surface of the substrate can be uniform, a thin film can be provided with a uniform film thickness and an even film quality with respect to an in-plane direction or in-between surfaces of the substrate. Further, bias of evacuation between the separation areas on both sides can be prevented. Therefore, the reaction gases can be prevented from passing through the separation areas and mixing with each other. Accordingly, reaction products can be prevented from being formed on areas other than the surface of the substrate. Thus, formation of particles can be prevented.
First Embodiment
[0082] Referring to FIG. 1 , which is a cut-away diagram taken along I-I′ line in FIG. 3 , a film deposition apparatus according to an embodiment of the present invention has a vacuum chamber 1 having a flattened cylinder shape, and a rotation table 2 that is located inside the chamber 1 and has a rotation center at a center of the vacuum chamber 1 . The vacuum chamber 1 is made so that a ceiling plate 11 can be separated from a chamber body 12 . The ceiling plate 11 is pressed onto the chamber body 12 via a ceiling member such as an O ring 13 , so that the vacuum chamber 1 is hermetically sealed. On the other hand, the ceiling plate 11 can be raised by a driving mechanism (not shown) when the ceiling plate 11 has to be removed from the chamber body 12 .
[0083] The rotation table 2 is fixed onto a cylindrically shaped core portion 21 . The core portion 21 is fixed on a top end of a rotational shaft 22 that extends in a vertical direction. The rotational shaft 22 penetrates a bottom portion 14 of the vacuum chamber 1 and is fixed at the lower end to a driving mechanism 23 that can rotate the rotational shaft 22 clockwise, in this embodiment. The rotation shaft 22 and the driving mechanism 23 are housed in a cylindrical case body 20 having an open upper surface. The case body 20 is hermetically fixed to a bottom surface of the bottom portion 14 via a flanged portion, which isolates an inner environment of the case body 20 from an outer environment.
[0084] As shown in FIGS. 2 and 3 , plural (five in the illustrated example) circular concave portions 24 , each of which receives a semiconductor wafer (hereinafter referred to as “wafer”) W, are formed along a rotation direction (circumferential direction) in a top surface of the rotation table 2 , although only one wafer W is illustrated in FIG. 3 . FIGS. 4A and 4B are expanded views of the rotation table 2 being cut across and horizontally expanded along its concentric circle. As shown in FIG. 4A , the concave portion 24 has a diameter slightly larger, for example, by 4 mm than the diameter of the wafer W and a depth equal to a thickness of the wafer W. Therefore, when the wafer W is placed in the concave portion 24 , a surface of the wafer W is at the same elevation of a surface of the rotation table 2 (an area of the rotation table where the wafer W is not placed). If there is a relatively large difference in height between the surface of the wafer W and the surface of the rotation table 2 , a change of pressure occurs at the portion of the difference. Therefore, from the aspect of attaining uniformity of film thickness in the in-plane direction, it is preferable to match the elevation of the surface of the wafer W and the elevation of the surface of the rotation table 2 . While matching the elevation of the surface of the wafer W and the height of the surface of the rotation table 2 may signify that the height difference of the surfaces of the wafer W and the rotation table is less than or equal to approximately 5 mm, the difference has to be as close to zero as possible to the extent allowed by machining accuracy. In the bottom of the concave portion 24 there are formed three through holes (not shown) through which three corresponding elevation pins (see FIG. 8 ) are raised/lowered. The elevation pins support a back surface of the wafer W and raises/lowers the wafer W.
[0085] The concave portions 24 are substrate receiving areas (wafer W receiving areas) provided to position the wafers W and prevent the wafers W from being thrown out by centrifugal force caused by rotation of the rotation table 2 . However, the wafer W receiving areas are not limited to the concave portions 24 , but may be performed by guide members that are provided along a circumferential direction on the surface of the rotation table 2 to hold the edges of the wafers W. In a case where the rotation table 2 is provided with a chuck mechanism (e.g., electrostatic chucks) for attracting the wafer W, the areas on which the wafers W are received by the attraction serve as the substrate receiving areas.
[0086] Referring again to FIGS. 2 and 3 , the chamber 1 includes a first reaction gas nozzle 31 , a second reaction gas nozzle 32 , and separation gas nozzles 41 , 42 above the rotation table 2 , all of which extend in radial directions and are arranged at predetermined angular intervals in a circumferential direction of the chamber 1 . With this configuration, the concave portions 24 can move through and below the nozzles 31 , 32 , 41 , and 42 . In the illustrated example, the second reaction gas nozzle 32 , the separation gas nozzle 41 , the first reaction gas nozzle 31 , and the separation gas nozzle 42 are arranged clockwise in this order. These gas nozzles 31 , 32 , 41 , and 42 penetrate the circumferential wall portion of the chamber body 12 and are supported by attaching their base ends, which are gas inlet ports 31 a, 32 a, 41 a, 42 a, respectively, on the outer circumference of the wall portion.
[0087] Although the gas nozzles 31 , 32 , 41 , 42 are introduced into the chamber 1 from the circumferential wall portion of the chamber 1 in the illustrated example, these nozzles 31 , 32 , 41 , 42 may be introduced from a ring-shaped protrusion portion 5 (described later). In this case, an L-shaped conduit may be provided in order to be open on the outer circumferential surface of the protrusion portion 5 and on the outer top surface of the ceiling plate 11 . With such an L-shaped conduit, the nozzle 31 ( 32 , 41 , 42 ) can be connected to one opening of the L-shaped conduit inside the chamber 1 and the gas inlet port 31 a ( 32 a, 41 a, 42 a ) can be connected to the other opening of the L-shaped conduit outside the chamber 1 .
[0088] As illustrated in FIG. 3 , the reaction gas nozzle 31 is connected to a first gas supplying source 38 a of bis(tertiary-butylamino)silane (BTBAS) (which is a first source gas) via a gas supply pipe 31 b including a valve 36 a and a flow rate adjusting part 37 a. The reaction gas nozzle 32 is connected to a second gas supplying source 38 b of O3 (ozone) gas (which is a second source gas) via a gas supply pipe 31 b including a valve 36 b and a flow rate adjusting part 37 b. Further, the separation gas nozzle 41 is connected to a N2 gas supplying source 38 c of N2 (nitrogen) (which is a separation gas as well as an inert gas) via a gas supply pipe 41 b including a valve 36 c and a flow rate adjusting part 37 c. The separation gas nozzle 42 is also connected to the N2 gas supplying source 38 c via a gas supplying pipe 42 b including a valve 36 d and a flow rate adjusting part 37 d.
[0089] The gas supply pipe 31 b provided between the reaction gas nozzle 31 and the valve 36 a is connected to the N2 gas supplying source 38 c via a valve 36 e and a flow rate adjusting part 38 c. As described below, N2 gas is supplied into the chamber 1 from the reaction gas nozzle 31 in a case of adjusting the flow ratio of evacuation gas. Likewise, the gas supply pipe 32 b provided between the reaction gas nozzle 32 and the valve 36 b is connected to the N2 gas supplying source 38 c via the valve 36 f and the flow rate adjusting part 37 f. The valves 36 a - 36 f and the flow rate adjusting parts 37 a - 37 f constitute a gas supply system 39 .
[0090] The reaction gas nozzles 31 , 32 have ejection holes 33 facing directly downward for ejecting reaction gases below. The ejection holes 33 are arranged at predetermined intervals (e.g., about 10 mm) in longitudinal directions of the reaction gas nozzles 31 , 32 . The ejection holes 33 have an inner diameter of about 0.5 mm, for example. The reaction gas nozzles 31 , 32 are a first reaction gas supplying portion and a second reaction gas supplying portion, respectively, in this embodiment. In addition, an area below the reaction gas nozzle 31 is a first process area 91 in which the BTBAS gas is adsorbed on the wafer W, and an area below the reaction gas nozzle 32 is a second process area 92 in which the O3 gas is adsorbed on the wafer W.
[0091] The separation gas nozzles 41 , 42 are provided in separation areas D that are configured to separate the first process area 91 and the second process area 92 . As shown in FIGS. 2 through 4 , in each of the separation areas D, a convex portion 4 is provided in a ceiling plate 11 of the chamber 1 in a manner protruding downwards. The convex portion has a top view shape of a sector. The convex portion 4 is formed by dividing a circle depicted along an inner circumferential wall of the chamber 1 . The circle has the rotation center of the rotation table 2 as its center. The convex portion 4 has a groove portion 43 provided at the circumferential center of the circle that extends in the radial direction of the circle. The separation gas nozzle 41 ( 42 ) is located in the groove portion 43 . The distance between the center axis of the separation gas nozzle 41 ( 42 ) and one side of the sector-shaped convex portion 4 (edge of the convex portion 4 towards an upstream side relative to relative to a rotation direction of the rotation table 2 ) is substantially equal to the distance between the center axis of the separation gas nozzle 41 ( 42 ) and the other side (edge of the convex portion 4 towards a downstream side relative to the rotation direction of the rotation table 2 ) of the sector-shaped convex portion 4 .
[0092] It is to be noted that, although the groove portion 43 is formed in a manner bisecting the convex portion 4 in this embodiment, the groove portion 42 may be formed so that an upstream side of the convex portion 4 relative to the rotation direction of the rotation table 2 is wider, in other embodiments.
[0093] Accordingly, in this embodiment, a flat low ceiling surface (first ceiling surface) 44 is provided as a lower surface of the convex portion 4 on both sides of the separation gas nozzle 41 ( 42 ) relative to the rotation direction of the rotation table 2 . Further, a high ceiling surface (second ceiling surface) 45 , which is positioned higher than the first ceiling surface 44 , is provided on both sides of the separation gas nozzle 41 ( 42 ) relative to the rotation direction of the rotation table 2 . The role of the convex portion 4 is to provide a separation space which is a narrow space between the convex portion 4 and the rotation table 2 for impeding the first and second reaction gases from entering the narrow space and preventing the first and second reaction gases from being mixed.
[0094] Taking the separation gas nozzle 41 as an example, the O3 gas from an upstream side of the rotation direction of the rotation table 2 is impeded from entering the space between the convex portion 4 and the rotation table 2 . Further, the BTBAS gas from a downstream side of the rotation direction of the rotation table 2 is impeded from entering the space between the convex portion 4 and the rotation table 2 . “Impeding the first and second reaction gases from entering” signifies that the N2 gas ejected as the separation gas from the separation gas nozzle 41 diffuses between the first ceiling surfaces 44 and the upper surfaces of the rotation table 2 and flows out to a space below the second ceiling surfaces 45 , which are adjacent to the corresponding first ceiling surfaces 44 in the illustrated example, so that the gases cannot enter the separation space from the space below the second ceiling surfaces 45 . “The gases cannot enter the separation space” not only signifies that the gases from the adjacent space below the second ceiling surfaces 45 are completely prevented from entering the space below the convex portion 4 , but that the gases from both sides cannot proceed farther toward the space below the convex portion 4 and thus be mixed with each other. Namely, as long as such effect can be attained, the separation area D can achieve the role of separating the first process area 91 and the second process area 92 . The narrowness of the narrow space is set so that the pressure difference between the narrow space (space below the convex portion 4 ) and the space adjacent to the narrow space (e.g., space below the second ceiling surface 45 ) is large enough to attain the effect of “the gases cannot enter the separation space”. The specific measurements of the narrow space differs depending on, for example, the area of the convex portion 4 . Further, the gases adsorbed on the wafer W can pass through below the convex portion 4 . Therefore, “impeding the first and second reaction gases from entering” signifies that the first and second reaction gases are in a gaseous phase.
[0095] In this embodiment, a wafer W having a diameter of about 300 mm is used as the target substrate. In this embodiment, at an area spaced about 140 mm from the rotation center of the rotation table 2 in the outer circumferential direction (border part between the convex portion 4 and the below-described convex portion 5 ), the convex portion 4 includes a part where the length is about 146 mm in the circumferential direction (length of arc concentric with the rotation table 2 ). Further, at an area corresponding to an outermost part of the wafer W receiving area (concave part 24 ), the convex portion includes a part where the length is about 502 mm in the circumferential direction. In the outermost part as illustrated in FIG. 4A , the length L of convex portion 4 on each side of the separation nozzle 41 ( 42 ) with respect to the circumferential direction is about 246 mm.
[0096] As illustrated in FIG. 4A , the height from a top surface of the rotation table 2 to the lower surface of the convex portion 4 (i.e. first ceiling surface 44 ) is indicated as “h”. The height h ranges from, for example, about 0.5 mm to 10 mm, and more preferably, about 4 mm. In this case, the number of rotations of the rotation table 2 is set to, for example, about 1 rpm-500 rpm. Accordingly, in order to attain a separating function at the separation area D, the size of the convex portion 4 and the height h from the surface of the rotation table 2 to the lower surface of the convex portion 4 (first ceiling surface 44 ) are to be set based on, for example, experimentation of the applicable range of the number of rotations of the rotation table 2 .
[0097] Not only nitrogen gas (N2) may be used as the separation gas but also inert gas such as argon (Ar) may be used. Further, other gases such as hydrogen (H 2 ) may be used. As long as the film deposition process is not affected, the kind of gas is not to be limited in particular. Further, not only inert gas such as the above-described N2 gas may be used as the gas for flow rate adjustment but also other gases may be used as long as the gas does not affect the film deposition process. In this embodiment, N2 gas is used as the separation gas as well as the inert gas; therefore, inert gas is not switched when initiating the film deposition process. Alternatively, different kinds of gases may be used for the separation gas and the inert gas.
[0098] A protrusion portion 5 is provided on a lower surface of the ceiling plate 11 so that the inner circumference of the protrusion portion 5 faces the outer circumference of the core portion 21 . The protrusion portion 5 opposes the rotation table 2 at an outer area of the core portion 21 . In addition, a lower surface of the protrusion portion 5 and a lower surface of the convex portion 4 form one plane surface. In other words, a height of the lower surface of the protrusion portion 5 from the rotation table 2 is the same as a height of the lower surface (ceiling surface 44 ) of the convex portion 4 . FIGS. 4A and 4B show the ceiling plate 11 being horizontally cut across an area including a portion substantially lower than the ceiling surface 45 but higher than the separation nozzles 41 , 42 . The convex portion 4 may not only be formed integrally with the protrusion portion 5 but may also be formed separately from the protrusion portion 5 .
[0099] The configuration of the combination of the convex portion 4 and the separation nozzle 41 ( 42 ) is fabricated by forming the groove portion 43 in a sector-shaped plate to be the convex portion 4 , and locating the separation gas nozzle 41 ( 42 ) in the groove portion 43 in the above embodiment. However, two sector-shaped plates may be attached on the lower surface of the ceiling plate 11 by screws so that the two sector-shaped plates are located on both sides of the separation gas nozzle 41 ( 42 ).
[0100] As described above, the lower surface of the ceiling plate 11 of the chamber 1 (i.e. ceiling when viewed from the wafer receiving area (concave portion 24 ) of the rotation table 2 includes the first ceiling surface 44 and the second ceiling surface 45 provided in a circumferential direction in a manner where the second ceiling surface 45 is positioned higher than the first ceiling surface 45 . FIG. 1 is a vertical cross-sectional view of an area having a high ceiling surface 45 . FIG. 5 is a vertical cross-sectional view of an area having a low ceiling surface 44 . The convex portion 4 has a bent portion 46 that bends in an L-shape at the outer circumferential edge of the convex portion 4 (area at the outer rim of the chamber 1 ). The sector-shaped convex portion 4 is provided towards the ceiling plate 11 and is configured to be detachable from the chamber body 12 . Therefore, a slight gap(s) is provided between the outer peripheral surface of the bent portion and the chamber body 12 . The same as the convex portion 4 , the bent portion 46 is also provided for impeding reaction gases from entering and preventing the reaction gases from mixing. The gaps between the bent portion 46 and the rotation table 2 and between the bent portion 46 and the chamber body 12 are set to have substantially the same measurements as the height h of the ceiling surface 44 with respect to the surface of the rotation table 2 . In this embodiment, from the standpoint of the surface of the rotation table 2 , the inner surface of the bent portion 46 serves as an inner circumferential wall of the chamber 1 .
[0101] As illustrated in FIG. 5 , the chamber body 12 has an inner circumferential wall formed as a vertical surface in the vicinity of the outer circumferential surface of the bent portion 46 in the separation area D. As illustrated in FIG. 1 , in an area other than the separation area D, the chamber body 12 has a dented portion (dented towards the outer side) with a notch having a rectangular cross section. The dented portion faces, for example, an area extending from the outer circumferential surface of the rotation table 2 to a bottom surface part 14 . In the dented portion, the areas with pressure communication between the first and second process areas 91 , 92 are referred to as first and second evacuation areas E 1 and E 2 , respectively. Accordingly, as illustrated in FIGS. 1 and 3 , first and second evacuation ports 61 and 62 are formed at corresponding bottom parts of the first and second evacuation areas E 1 and E 2 .
[0102] As illustrated in FIG. 1 , the first evacuation port 61 is connected to, for example, a vacuum pump (first evacuation part) 64 a via a first evacuation channel 63 a. A first valve 65 a is interposed between the first evacuation channel 63 a and the vacuum pump 64 a. The first valve 65 a includes, for example, an APC (Auto Pressure Controller) that can change the opening (degree in which the first valve 65 a is opened). The flow rate of the gas flowing in the first evacuation channel 63 a can be adjusted in correspondence with the opening of the first valve 65 a. A first process pressure detecting part 66 a is connected to an upstream side of the first valve 65 a (towards the chamber 1 ). A first pressure detecting part 67 a is connected to a downstream side of the first valve 65 a (towards the vacuum pump 64 a ). The first process pressure detecting part 66 a and the first pressure detecting part 67 a each includes a pressure gage. The first process pressure detecting part 66 a is for measuring the pressure in the chamber 1 (upstream side of the first valve 65 a ). The first pressure detecting part 67 a is for measuring the pressure between the first valve 65 a and the vacuum pump 64 a. Based on the difference in the values detected by the first process pressure detecting part 66 a and the first pressure detecting part 67 a, the below-described control part 80 calculates the flow rate of gas flowing inside the first evacuation channel 63 a taking the pressure drop at the first evacuation channel 63 a or the first valve 65 a into consideration. The calculation may be performed using, for example, Bernoulli's law.
[0103] Likewise, the second evacuation port 62 is connected to, for example, a vacuum pump (first evacuation part) 64 b via a second evacuation channel 63 b. A second valve 65 b is interposed between the second evacuation channel 63 b and the vacuum pump 64 b. The same as the first valve 65 a, the second valve 65 b includes, for example, an APC (Auto Pressure Controller) that can change the opening (degree in which the second valve 65 b is opened). The flow rate of the gas flowing in the second evacuation channel 63 b can be adjusted in correspondence with the opening of the second valve 65 b. A second process pressure detecting part 66 b is connected to an upstream side of the second valve 65 b (towards the chamber 1 ). A second pressure detecting part 67 b is connected to a downstream side of the second valve 65 b (towards the vacuum pump 64 b ). The second process pressure detecting part 66 b and the second pressure detecting part 67 b each includes a pressure gage. The second process pressure detecting part 66 b is for measuring the pressure in the chamber 1 (upstream side of the second valve 65 b ). The second pressure detecting part 67 b is for measuring the pressure between the second valve 65 b and the vacuum pump 64 b. Based on the difference in the values detected by the second process pressure detecting part 66 b and the second pressure detecting part 67 b, the control part 80 calculates the flow rate of gas flowing inside the second evacuation channel 63 b taking the pressure drop at the second evacuation channel 63 b or the second valve 65 b into consideration. Hereinafter, the first valve 65 a may also be referred to as “valve M (Master)” and the second valve 65 b may also be referred to as “valve S (Slave)”.
[0104] The first and second evacuation ports 61 and 62 are provided for ensuring a separating effect in the separation area D. When viewing the first and second evacuation ports 61 , 62 from a plan position, the first and second evacuation ports 61 , 62 are provided on both sides of the separation area D in the rotation direction. For example, when viewing the first evacuation port 61 from the rotation center of the rotation table 2 , the first evacuation port 61 is formed between the first process area 91 and the separation area D provided adjacent to the first process area 91 towards the downstream side of the first process area 91 with respect to the rotation direction. When viewing the second evacuation port 62 from the rotation center of the rotation table 2 , the second evacuation port 62 is formed between the second process area 92 and another separation area D provided adjacent to the second process area 92 towards the downstream side of the second process area 92 . Each of the evacuation ports 61 , 62 is dedicated to evacuate a corresponding reaction gas (BTBAS gas and O3 gas). In this embodiment, the first evacuation port 61 is provided between the first reaction gas nozzle 31 and a line extending from an edge (edge towards the first reaction gas nozzle 31 ) of the separation area D provided towards the downstream side of the first process area 91 with respect to the rotation direction. The second evacuation port 62 is provided between the second reaction gas nozzle 32 and a line extending from an edge (edge towards the second reaction gas nozzle 31 ) of the separation area D provided towards the downstream side of the second process area 92 with respect to the rotation direction. In other words, as illustrated in FIG. 3 , the first evacuation port 61 is provided between a straight line L 1 (passing through the center of the rotation table 2 and the first process area 91 ) and a straight line L 2 (passing through the center of the rotation table 2 and an upstream edge of the separation area D provided towards the downstream side of the first process area 91 with respect to the rotation direction). The second evacuation port 62 is provided between a straight line L 3 (dash-double-dot line passing through the center of the rotation table 2 and the second process area 92 ) and a straight line L 4 (dash-double-dot line passing through the center of the rotation table 2 and an upstream edge of the separation area D provided towards the downstream side of the second process area 92 with respect to the rotation direction).
[0105] Because the pressure detected from both the first process pressure detecting part 66 a and the second process pressure detecting part 66 b are substantially the same, a pressure value detected from either the first process pressure detecting part 66 a or the second process pressure detecting part 66 b can be used as the value of the pressure in the area upstream of the valves 65 a, 65 b for calculating the flow rate in each of the first and second evacuation channels 63 a, 63 b. Because the pressure of the evacuation channels 63 a, 63 b located upstream of the valves 65 a, 65 b is substantially the same as the pressure inside the chamber 1 , a pressure value detected from another pressure detecting part provided in the chamber 1 may serve as the pressure value used to calculate the flow rate in each of the first and second evacuation channels 63 a, 63 b instead of using the pressure values detected by the process pressure detecting parts 66 a, 66 b.
[0106] Although the two evacuation ports 61 , 62 are made in the chamber body 12 in this embodiment, three evacuation ports may be provided in other embodiments. For example, an additional evacuation port may be made in an area between the second reaction gas nozzle 32 and the separation area D located upstream relative to the clockwise rotation of the rotation table 2 in relation to the second reaction gas nozzle 32 . In addition, a further additional evacuation port may be made somewhere in the chamber body 12 . While the evacuation ports 61 , 62 are located below the rotation table 2 to evacuate the chamber 1 through an area between the inner circumferential wall of the chamber 1 and the outer circumferential surface of the rotation table 2 in the illustrated example, the evacuation ports may be located at a part other than the bottom portion 14 of the chamber 1 . For example, the evacuation ports may be located in the side wall of the chamber body 12 . In addition, when the evacuation ports 61 , 62 are provided in the side wall of the chamber body 12 , the evacuation ports 61 , 62 may be located higher than the rotation table 2 . In this case, the gases flow along the upper surface of the rotation table 2 into the evacuation ports 61 , 62 located higher the rotation table 2 . Therefore, it is advantageous in that particles in the chamber 1 are not blown upward by the gases, compared to when the evacuation ports are provided, for example, in the ceiling plate 11 .
[0107] As shown in FIGS. 1 and 6 , a heater unit (heating portion) 7 is provided in a space between the bottom portion 14 of the chamber 1 and the rotation table 2 , so that the wafers W placed on the rotation table 2 are heated through the rotation table 2 at a temperature determined by a process recipe. In addition, a cover member 71 is provided beneath the rotation table 2 and near the outer circumference of the rotation table 2 in order to surround the heater unit 7 , so that the space where the heater unit 7 is located is partitioned from the outside area of the cover member 71 . The cover member 71 has a flange portion 71 a at the top. The flange portion 71 a is arranged so that a slight gap is maintained between the back surface of the rotation table 2 and the flange portion in order to prevent gas from flowing inside the cover member 71 .
[0108] At an area located towards the bottom portion 14 and more towards the rotation center than the space where the heater unit 7 is provided, narrow spaces are provided in the vicinity of the center of the lower surface of the rotation table 2 and the core portion 21 . Further, slight gaps, which are provided at a penetration hole through which the rotation shaft 22 passes, are in communication with the inside of the case body 20 . A purge gas supplying pipe 72 is connected to the case body for supplying a purge gas such as N2 gas to the aforementioned narrow spaces. Purge gas supplying pipes 73 are connected to plural areas in the circumferential direction at the bottom portion of the chamber 1 for purging the space where the heater unit 7 is provided.
[0109] By providing the purge gas supplying pipes 72 , 73 , N2 gas is purged into the space extending from the inside of the case body 20 to the area where the heater unit 7 is provided. The purge gas is evacuated from the gap between the rotation table 2 and the cover member 71 to the evacuation ports 61 , 62 via an evacuation area E. Accordingly, because the BTBAS gas or O3 gas is prevented from circling around from one side of the first process area 91 and the second process area 92 to the other side of the first process area 91 and the second process area 92 via a lower part of the rotation table 2 , the purge gas plays the role of a separation gas.
[0110] A gas separation supplying pipe 51 is connected to the top center portion of the ceiling plate 11 of the chamber 1 , so that N2 gas is supplied as a separation gas to a space 52 between the ceiling plate 11 and the core portion 21 . The separation gas, which is supplied to the space 52 , is ejected towards the circumferential edges through the thin gap 50 between the protrusion portion 5 and the rotation table 2 and then along the wafer receiving area of the rotation table 2 . Because the separation gas fills the space surrounded by the protrusion portion 5 , reaction gases (BTBAS gas or O3 gas) can be prevented from mixing via the center portion of the rotation table 2 between the first process area 91 and the second process area 92 . That is, the film deposition apparatus according to this embodiment is divided into a rotation center portion of the rotation table 2 and the chamber 1 for separating the atmosphere between the first process area 91 and the second process area 92 . Further, the film deposition apparatus according to this embodiment is provided with a center area C having an ejection opening formed along a rotation direction at the center portion of the rotation table 2 for ejecting the separation gas on the surface of the rotation table 2 . The ejection opening corresponds to the narrow gap 50 between the protrusion portion 5 and the rotation table 2 .
[0111] As illustrated in FIGS. 2 , 3 , and 3 , a transfer opening 15 is formed in a side wall of the chamber 1 for transferring a wafer W between an outside transfer arm 10 and the rotation table 2 . The transfer opening 15 is provided with a gate valve (not illustrated) by which the transfer opening 15 is opened or closed. When a concave portion (wafer receiving area) 24 of the rotation table 2 is in alignment with the transfer opening 15 , the wafer W is transferred into the chamber 1 and placed in the concave portion 24 as a wafer receiving portion of the rotation table 2 from the transfer arm 10 . In order to lower/raise the wafer W into/from the concave portion 24 , there are provided elevation pins 16 that are raised or lowered through corresponding through holes formed in the concave portion 24 of the rotation table 2 by an elevation mechanism (not illustrated).
[0112] As illustrated in FIG. 9 , the film deposition apparatus according to an embodiment of the present invention includes a control part 80 including a computer for controlling overall operations of the film deposition apparatus. The control part 80 includes a CPU 81 , a memory 82 , a processing program 83 , a work memory 84 , and a timer 86 . In the memory 82 , processing conditions (e.g., flow rate Va of BTBAS gas supplied from the first reaction gas nozzle 31 , flow rate Vb of O3 gas supplied from the second reaction gas nozzle 32 , process pressure P, flow ratio F of gas evacuated from the first evacuation channel 63 a and the second evacuation channel 63 b (i.e. flow rate of gas flowing in the second evacuation channel/flow rate of gas flowing in the first evacuation channel) are recorded thereto with respect to each recipe. In a steady state, the flow ratio F of the gases is set so that the flow of gas supplied to the wafer W in the first and second process chambers 91 , 92 is constant (stable) with respect to an in-plane direction or in-between surfaces of the wafers W. For example, process temperature or a process pressure is stabilized to a value of a corresponding recipe. Further, the values of the flow rate of gas evacuated from the first and second evacuation channels 63 a, 63 b are set to be a flow rate corresponding to the gas supplied from the first reaction gas nozzle 31 and the second reaction gas nozzle 32 (including N2 gas supplied as purge gas).
[0113] The processing program 83 has commands assembled thereto for processing the wafer W by loading a corresponding recipe recorded in the memory 82 to the work memory 84 , transmitting control signals to each part of the film deposition apparatus according to the recipe, and executing each of the below-described steps. The processing program 83 is for setting a value of a processing temperature read out from a recipe before the BTBAS gas or O3 gas is supplied (i.e. before a film deposition process). Further, N2 gas is supplied into the chamber 1 at a flow rate substantially the same as the total flow rate of gas supplied during processing. In this state, the opening of the first valve 65 a and the opening of the second valve 65 b are adjusted according to each pressure value detected by the first process pressure detecting part 66 a ( 66 b ) and a pressure detecting part 67 so that the flow ratio F evacuated from the first and second evacuation channels 63 a and 63 b and the pressure P (degree of vacuum) inside the chamber 1 become predetermined values, to thereby stabilize the flow of gas supplied to the wafer W (steady state). After reaching the steady state, the processing program 83 commands a film deposition process to be executed in which BTBAS gas or O3 gas is supplied. In adjusting the flow ratio F of the evacuation gases and the pressure inside the chamber 1 , the adjustment is repeated for a predetermined time (number of times), for example, performing a first step of adjusting the pressure P inside the chamber 1 with the first valve 65 a, performing a second step of adjusting the flow ratio of the evacuation gases with the second valve 65 b, and then performing the first step again (described in detail below). Although the flow ratio F of the evacuation gases is different with respect to each recipe, the flow ratio F of the evacuation gases may be the same with respect to each recipe.
[0114] A timer 86 is for setting the time (number of times) for repeating the valve 65 adjustment by the processing program 83 . For example, the time for the repetition may be set to automatic or may be set by a user according to each recipe.
[0115] The processing program 83 may be installed to the control part 80 from a storage medium such as a hard disk, a compact disk, a magneto-optical magnetic disk, a memory card, or a flexible disk.
[0116] A film deposition operation according to an embodiment of the present invention is described with reference to FIGS. 10-15 . First, a recipe is read out from the memory 82 . Then, agate valve (not illustrated) is opened, and a wafer W is transferred into the concave portion 24 of the rotation table 2 from outside via the transfer opening 15 by the transfer arm 10 (Step S 11 ). The transfer is performed by raising or lowering the elevation pins 16 from the bottom portion of the chamber 1 via the through holes formed at the bottom surface of the concave portion 24 as illustrated in FIG. 8 . In this example, the transfer is performed by intermittently rotating the rotation table 2 and placing wafers W on five corresponding concave portions 24 of the rotation table 2 . Then, the rotation table 2 is rotated clockwise at the substantially the same number of rotations when performing film deposition (Step S 12 ). Then, the adjustment of the pressure P inside the chamber 1 and the adjustment of the flow ratio F of evacuation gases are performed in Step S 13 (described in detail in Steps S 21 -S 28 ).
[0117] First, the chamber 1 is evacuated by fully opening the first and second valves 65 a, 65 b together with heating the wafer W at a predetermined temperature (e.g., 300° C.) with the heater unit 7 (Step 521 ). For example, the wafer W is heated to a predetermined temperature by heating the rotation table 2 beforehand to a temperature of 300° C. with the heater unit 7 and placing the wafer W on the rotation table 2 . Then, N2 gas is supplied into the chamber 1 in substantially the same flow rate as the total flow rate of gas supplied in the chamber 1 when performing the below-described film deposition process. In order to attain substantially the same flow rate as the flow rate of gas supplied from the nozzles 31 , 32 , 41 , 42 during the film deposition process, each of the separation gas nozzles 41 , 42 supplies N2 gas with a flow rate of 20000 sccm, the first reaction gas nozzle 31 supplies N2 gas with a flow rate of 100 sccm, and the second reaction gas nozzle 32 supplies N2 gas with a flow rate of 10000 sccm. Further, the separation gas supplying pipe 51 and the purge gas supplying pipe 72 also supply N2 gas with a predetermined flow rate to the center portion area C and the aforementioned narrow gaps. Further, in order to attain a predetermined value of a recipe, the pressure value P 1 is set to, for example, 1067 Pa (8 Torr), and the flow ratio F 1 is set to, for example, 1.5 (Step S 22 ). Then, the timer 86 is set for setting the time t 1 for repeating the below-described Steps S 24 -S 27 (Step S 23 ).
[0118] As illustrated in FIG. 13 , in order for the pressure P in the chamber 1 to be a predetermined pressure value P 1 (e.g., 1067 Pa (8 Torr), the opening (A 1 ) of the first valve 65 a is adjusted (Step S 24 ). For example, in order to reduce the flow rate of gas flowing in the first evacuation channel 63 a, the opening of the first valve 65 a is reduced. The flow rate of each gas flowing in the evacuation channels 63 a, 63 b (Qa 1 , Qb 1 ) is calculated according to the pressure difference between the pressure of an upstream side (front) of the first valve 65 a and the pressure of a downstream side (back) of the first valve 65 a (ΔPa 1 ) and the pressure difference between the pressure of an upstream side (front) of the second valve 65 b and the pressure of a downstream side (back) of the second valve 65 b (ΔPb 1 ). Then, the gas flow ratio F (Qb 1 /Qa 1 ) is obtained based on the calculated flow rate, to thereby determine whether the flow ratio is a predetermined value F 1 (Step S 25 ). In a case where the flow ratio is equal to the predetermined value F 1 , the operation proceeds to the below-described film deposition process of Step S 14 . In a case where the flow ratio is greater than the predetermined value F 1 , the opening (B 1 ) of the second valve 65 b is reduced so that the flow ratio equals to the predetermined value F 1 (Step S 26 ).
[0119] Then, it is determined whether the pressure P is deviated from a predetermine value P 1 (Step S 27 ). If the pressure P is not deviated from the predetermined value P 1 , the operation proceeds to the below-described film deposition process of Step S 14 . In a case where the pressure P is deviated from the predetermined value P 1 , it is determined whether the time used in performing the above-described steps S 24 -S 27 has reached a predetermined repetition time t 1 (Step S 28 ). The steps of S 24 -S 27 are repeated when i) the time used in performing the step S 24 -S 27 reaches the repetition time t 1 , ii) the flow ratio F equals to the predetermined value F 1 in Step S 25 , or iii) the pressure P equals to the predetermined value P 1 . For example, in a case where the pressure P is greater than P 1 by the adjustment of the opening of the valve 65 b (Step S 26 ), the opening of the valve 65 a is increased. In a case where the pressure P is less than P 1 by the adjustment of the opening of the valve 65 b (Step S 26 ), the opening of the valve 65 a is reduced. In a case where the flow ratio F is greater than F 1 by the adjustment of the opening of the valve 65 a (Step S 24 ), the opening of the valve 65 b is reduced. In a case where the flow ratio is less than F 1 by the adjustment of the opening of the valve 65 b (Step S 24 ), the opening of the valve 65 b is increased. Accordingly, by alternately adjusting the opening of the valves 65 a, 65 b, each of the pressure P and the flow ratio F becomes closer to the corresponding predetermined values P 1 , F 1 .
[0120] In a case where the pressure P and the flow ratio F reach the predetermined value P 1 , F 1 by performing the steps S 24 -S 27 , the flow rate of the gas evacuated from the evacuation channels 63 a, 63 b become 20 sccm, 30 sccm, respectively. As illustrated in FIG. 12B , each of the opening of the first valve 65 a and the opening of the second valve 65 b is set to, for example, A 2 , B 2 , respectively. Even in a case where time is up in Step S 28 , the amount of deviation between the adjusted pressure P and the predetermined value P 1 and the amount of deviation between the adjusted flow ratio F and the predetermined flow ratio F 1 becomes smaller as the aforementioned Steps S 24 -S 27 are repeated because the adjustment of the pressure P of the first pressure valve 65 a and the adjustment of the pressure of the second pressure valve 65 b are alternately performed. Accordingly, the pressure P and the flow ratio F are significantly close to the corresponding predetermined value P 1 and F 1 even when the time is up. Therefore, the operation proceeds to the film deposition process of Step S 14 even in the case where the time is up.
[0121] In order to maintain the pressure P and the flow ratio F set by performing the above-described steps, the opening of the first valve 65 a and the opening of the second valve 65 b are slightly adjusted. In this embodiment, a wide area is provided by cutting out (notching) the inner circumferential wall of the chamber body 12 provided at a lower side of the second ceiling surface 45 . The evacuation ports 61 , 62 are provided below this wide space. Accordingly, the pressure in the space below the second ceiling surface 45 is lower than the pressure in the narrow space below the first ceiling surface 44 and lower than the pressure in the center portion area C.
[0122] Then, it is determined whether the temperature of the wafer W has reached a predetermined temperature by a temperature sensor (not illustrated) and whether the pressure P in the chamber 1 and the flow ratio F of the evacuation gases has stabilized to a steady state. Then, as FIG. 14A shows, the gases supplied from the first and second reaction nozzles 31 , 32 are switched from N2 gas to BTBAS gas and O3 gas, respectively (Step S 14 ). As illustrated in FIG. 14B , the gases are switched in a manner that the total flow rate of the gases supplied to the chamber 1 (gases supplied from the nozzles 31 , 32 ) does not change. By switching the gases in this manner, change in the flow of gases applied to the wafer W as well as the pressure inside the chamber 1 can be restrained. Accordingly, as illustrated in FIG. 12C , the pressure P inside the chamber 1 and the flow ratio F of evacuation gas can be maintained at predetermined values P 1 and F 1 without having to perform adjustment of the first and second valves 65 a, 65 b by performing the steps S 21 -S 28 .
[0123] Because the inside of the chamber 1 can be maintained at a steady state after gases are switched, the flow of gas with respect to an in-plane direction or in-between surfaces of the wafer W can be stabilized as illustrated in FIG. 15 . Further, the flow of gas supplied to the wafer W during the film deposition process maintains a steady state because the opening of the valve 65 a, 65 b are slightly adjusted during the film deposition process in a manner that the flow ratio F of the gases evacuated from the evacuation channels 63 a, 63 b are maintained at the predetermined value F 1 . It is to be noted that the flow rate of each gas is schematically illustrated in FIG. 14A .
[0124] Because the wafers W alternately pass through the first and second process areas 91 , 92 by the rotation of the rotation table 2 , BTBAS gas is adsorbed to the wafer W and then O3 is adsorbed to the wafer W. Thereby, one or more layers of silicon oxide are formed on the wafer W. Accordingly, a silicon oxide film having a predetermined film thickness can be deposited by forming molecular layers of silicon oxide.
[0125] In this case, N2 gas is supplied between the first and second process areas 91 , 92 . Further, N2 is also supplied to the center portion area C as separation gas. Further, the valve 65 a, 65 b are slightly adjusted so that the flow of gas supplied to the wafer W is stabilized. Accordingly, each of the BTBAS gas and the O3 gas can be evacuated so that the BTBAS gas and the O3 gas can be prevented from being mixed. Further, in the separation area(s), because the gap between the bent portion 46 and the outer edge surface of the rotation table 2 is narrow, the BTBAS gas and the O3 gas do not mix even via the outer side of the rotation table 2 . Therefore, the atmosphere of the first process area 91 and the atmosphere of the second process area 92 are substantially completely separated. Thus, the BTBAS gas is evacuated from the evacuation port 61 whereas the O3 gas is evacuated from the evacuation port 62 . As a result, the BTBAS gas and the O3 gas do not mix in both the atmospheres of the first and second process areas 91 , 92 and on the surface of the wafers W.
[0126] In this embodiment, gas entering the evacuation area E can be prevented from passing under a lower part of the rotation table 2 because the lower part of the rotation table 2 is purged with N2 gas. Thus, for example, BTBAS gas can be prevented from entering the area where O3 gas is supplied. After the film deposition process is completed, the supply of gases are stopped and each wafer W is transferred outside in order by the transfer arm 10 (Step S 16 ).
[0127] An example of process parameters preferable in the film deposition apparatus according to this embodiment is listed below.
rotational speed of the rotation table 2 : 1-500 rpm (in the case of the wafer W having a diameter of 300 mm) flow rate of N2 gas from the separation gas pipe 51 : 5000 sccm the number of rotations of the rotation table 2 (number of times in which the wafer W passes the process areas 91 , 92 ): 600 rotations (depending on the film thickness required)
[0131] With the above-described embodiment, first and second process areas 91 , 92 to which the reaction gases of BTSAS gases and O3 gases are supplied are formed in the same chamber in the rotation direction of the rotation table 2 . When forming a thin film by forming plural layers of reaction products by passing a wafer W through the first and second process chambers 91 , 92 by rotating the rotation table 2 , separation gas is supplied to a separation area between the first and second process areas, separation areas D are provided between the first and second process chambers 91 , 92 along with providing first and second evacuation channels 63 a, 63 b including evacuation ports 63 a, 63 b for separating and evacuating different reaction gases. The opening of the first valve 65 a and the opening of the second valve 65 b are adjusted so that the flow ratio F of the gases evacuated from the evacuation channels 63 a, 63 b becomes a predetermined value F 1 , and the pressure P inside the chamber 1 becomes P 1 . Therefore, the flow of gas on both sides of the separation areas can be stabilized. Thus, because the flow of the reaction gases (BATAS, O3) applied to the surface of the wafer W can be stabilized, the adsorption of BTBAS gas can be stabilized and the oxide reaction of the adsorbed molecules of O3 gas can be stabilized. As a result, the wafer W can obtain a satisfactory thin film having an even film thickness with respect to an in-plane direction or in-between surfaces of the wafer W.
[0132] Furthermore, because bias of evacuation on both sides of the separation areas D can be prevented, BTBAS gas and O3 gas can be prevented from passing through the separation areas and become mixed. Accordingly, reaction products can be prevented from being formed on areas besides the surface of the wafers W. Thus, formation of particles can be prevented. It is to be noted that the above-described embodiment of the present invention may be applied to a case where a single wafer is placed on the rotation table 2 .
[0133] In the above-described embodiment of the present invention, both the first and second valves 65 a, 65 b are fully evacuated in Step S 21 . Alternatively, in a case where the first valve 65 a is adjusted in Step S 24 , the second valve 65 b can have its opening adjusted in the same manner by calculating the opening of the second valve 65 b and the flow rate of the gas evacuated from the second evacuation chamber 63 b. In this case, adjustment of the pressure value and adjustment of flow ratio can both be speedily performed. In this case, the pressure or the flow ratio that is adjusted becomes less (amount of change), and a reaction gas other than N2 gas may be used to adjust pressure or flow ratio.
[0134] In the above-described embodiment of the present invention, the flow rate of N2 gas when adjusting the pressure P or the flow ratio F is set to be substantially the same flow rate of the reaction gas when switching gases and performing film deposition. However, as long as the flow rate of N2 gas when adjusting the pressure P or the flow ratio F is near the flow rate of the reaction gas when switching gases and performing film deposition (e.g., ±5), turbulence of the gas applied to the wafer W can be suppressed.
[0135] In the above-described embodiment of the present invention, when time is up in Step S 28 , the operation proceeds to steps S 14 and thereafter is assumed that the pressure P and the flow ratio F are substantially close to corresponding predetermined values P 1 , F 1 . An alarm may be output for stopping a subsequent film deposition process.
Second Embodiment
[0136] In the first embodiment, the pressure in the chamber 1 and the flow ratio F of the evacuation channels 63 a, 63 b are controlled by relying only on the adjustments of the opening of the first and second valves 65 a, 65 b. Alternatively, the control maybe performed by further adding adjustment of the flow rate (evacuation performance) of the evacuation pump 64 b by adjusting the number of rotations of the evacuation pump 64 b.
[0137] As illustrated in FIG. 16 , the evacuation pump 64 b is connected to an inverter 68 serving as a part for adjusting evacuation flow rate of the evacuation pump 64 b. The inverter 68 is configured to adjust the electric current flowing in the evacuation pump 64 b, that is the number of rotations (evacuation flow rate) of the evacuation pump 64 b. Accordingly, in this embodiment, the number of rotations R of the evacuation pump 64 b is stored in correspondence with this recipe. It is to be noted that, components and effects of the film deposition apparatus according to this embodiment is substantially the same as the above-described embodiments of the present invention and further explanation thereof is omitted.
[0138] As illustrated in FIG. 17 , in a case where the time is up after repeating the steps of controlling the pressure of the first valve 65 a and controlling the flow rate of the second valve 65 b (Step S 28 ), the third step of adjusting the number of rotations R of the evacuation pump 64 b is performed (Step S 29 ). For example, after the flow ratio F is adjusted by the second valve 65 b (Step S 26 ), the pressure P is determined (Step S 27 ). In a case where the pressure P is deviated from the predetermined value P 1 , the amount of evacuation of the evacuation pump 64 b is adjusted so that the pressure P becomes the predetermined value P 1 . For example, in a case where the pressure is equal to or greater than the predetermined value P 1 , that is, in a case where the evacuation amount of the evacuation pump 64 b is insufficient, the value of the electric current of the inverter 68 is set so that the evacuation amount of the evacuation pump 64 b is increased by increasing the number of rotations R of the vacuum pump 64 b. On the other hand, in a case where the pressure P is less than the predetermined value P 1 , the evacuation amount of the evacuation pump 64 b is reduced by reducing the number of rotations R of the evacuation pump 64 b.
[0139] Then, the above-described steps S 24 -S 27 are repeated after resetting the repetition time t 1 with the timer 86 . In a case where the pressure P and the flow ratio F are adjusted to the predetermined values P 1 and F 1 in Steps S 25 and S 27 , the operation proceeds to the film deposition process (Step S 14 ). In a case where the pressure P and the flow ratio F has not reached the predetermined values P 1 and F 1 even by the adjustment of the number of rotations R of the evacuation pump 64 b, adjustment of the number of rotations R of the evacuation pump 64 b is repeated in Step S 29 . The steps S 24 -S 28 are repeated until the repetition time t 1 elapses or the pressure P and the flow ratio F reach the predetermined values P 1 and F 1 . It is to be noted that even in a case where the pressure P and the flow ratio F has not reached the predetermined values P 1 and F 1 after the elapse of the repetition time t 1 , the adjusted pressure P and the adjusted flow ratio F become closer towards corresponding predetermined values P 1 and F 1 becomes smaller because the opening of the valves 65 a, 65 b and the number of rotations R of the evacuation pump 64 b are adjusted. Accordingly, the pressure P and the flow ratio F become close to the predetermined values P 1 and the flow ratio F even when the time is up. Thus, the operation proceeds to the film deposition process of Step S 14 even in the case where the time is up.
[0140] With the above-described embodiment of the present invention, the following effect can be obtained. That is, even in a case where the pressure P and the flow ratio F cannot be adjusted to the predetermined values P 1 and F 1 within the repetition time (t 1 ) by adjusting the opening of the first and second valves 65 a, 65 b, the opening of the first and second valves 65 a, 65 b can be re-adjusted by adjusting the number of rotations R of the evacuation pump 64 b. Therefore, even if there is a difference in the evacuation performance between the evacuation pumps 64 a, 64 b, the pressure P and the flow ratio F can be set to become the predetermined values P 1 and F 1 . In other words, by adjusting the number of rotations R of the evacuation pump 64 b along with adjusting the opening of the valves 65 a, 65 b, the pressure P and the flow ratio F can be set in a wide range.
[0141] In the above-described embodiment, the number of rotations R of the evacuation pump 64 b is adjusted. Alternatively, the evacuation pump 64 a may be connected to the inverter so that the number of rotation of the evacuation pump 64 a is adjusted instead of the evacuation pump 64 b. Alternatively, the number of rotations of both the evacuation pumps 64 a and 64 b may be adjusted. In a case of adjusting the number of rotations R of both the evacuation pumps 64 a and 64 b, the number of rotations R of both the evacuation pumps 64 a and 64 b may be adjusted simultaneously in Step S 29 . Alternatively, in a case of adjusting the number of rotations R of both the evacuation pumps 64 a and 64 b, the number of rotations R of the evacuation pump 64 b is adjusted in Step S 29 , then the number of rotations R of the evacuation pump 64 a is adjusted after the time is up in Step S 28 , then the repetition time t 1 is set in Step S 23 , and then the opening of the valves 65 a, 65 b are adjusted in Steps S 24 -S 28 .
[0142] In the above-described embodiment, the step S 29 is performed when the time is up in Step S 28 . Alternatively, the step S 29 may be performed between steps S 27 and S 28 , so that the adjustment of the opening of the valves 65 a, 65 b is repeated along with the adjustment of the number of rotations R of the evacuation pump 64 a, for example. Further, in the step S 27 (before repeating each step), the step S 29 may be performed before repeating the steps S 24 -S 27 in a case where, for example, the pressure P is significantly deviates from the predetermined value P 1 .
[0143] In the above-described embodiment, generation of reaction products inside the evacuation passages 63 a, 63 b and the evacuation pump 64 is prevented by separately evacuating the reaction gases from two evacuation passages 63 a, 63 b. In a case where reaction of reaction gases is unlikely to occur where the temperature inside the evacuation passages 63 a, 63 b and the evacuation pump 64 is low, the evacuation pumps 64 a, 64 b may be formed into a shared evacuation pump 64 as illustrated in FIG. 18 . In this case, the cost of the film deposition apparatus can be reduced.
[0144] As for process gases that are used in the present invention other than those of the above-described embodiments of the present invention, there are dichlorosilane (DCS), hexachlorodisilane (HCD), Trimethyl Aluminum (TMA), tris(dimethyl amino)silane (3DMAS), tetrakis-ethyl-methyl-amino-zirconium (TEMAZr), tetrakis-ethyl-methyl-amino-hafnium (TEMHf), bis(tetra methyl heptandionate)strontium (Sr (THD) 2 ) (methyl-pentadionate)(bis-tetra-methyl-heptandionate)titanium (Ti(MPD)(THD)), monoamino-silane, or the like.
[0145] Because gas flows toward the separation area D at a higher speed in the position closer to the outer circumference of the rotation table 2 , it is preferable that the width of an upstream area of the ceiling surface 44 of the separation area D with respect to the separation gas nozzles 41 , 42 to be greater than the area located at the outer circumference of the rotation table 2 . In view of this, it is preferable for the convex portion 4 to have a sector-shape.
[0146] As illustrated in FIGS. 19A and 19B , in a case where a wafer W having a diameter of, for example, 300 mm is used as the target substrate, the ceiling surface 44 that creates the thin space in both sides of the separation gas nozzle 41 is preferred to have a width L equal to or greater than 50 mm in the rotation direction of the rotation table 2 at a portion where the center WO of the wafer W passes. In order to effectively prevent reaction gases from entering an area below the convex portion 4 from both sides of the convex portion 4 , the distance h between the first ceiling surface 44 and the rotation table 2 is made to be short in a case where the width L is small. Further, in a case where a predetermined length is set to the distance h between the first ceiling surface 44 and the rotation table 2 , the speed of the rotation table 2 becomes faster the farther away from the rotation center of the rotation table 2 . Therefore, the width L required for attaining a reaction gas impeding effect becomes greater the farther away from the rotation center. When the width L is small, the height h of the thin space between the ceiling surface 44 and the rotation table 2 (wafer W) has to be made accordingly small in order to effectively prevent the reaction gases from flowing into the thin space. It is, therefore, necessary to reduce the vibration of the rotation table 2 as much as possible for preventing collision between the rotation table 2 or the wafer W and the ceiling surface 44 when the rotation table 2 is rotated. Further, it becomes easier for reactions gases to enter the lower part of the convex portion 4 from upstream of the convex portion 4 as the number of rotations of the rotation table 2 increases. Thus, when the width L is less than 50 mm, it becomes necessary to reduce the number of rotations of the rotation table 2 which is rather disadvantageous in terms of production throughput. Therefore, it is preferable for the width L to be equal to or greater than 50 mm. Nevertheless, the effects of the present invention may still be attained where the width L is equal to or less than 50 mm. In other words, it is preferable for the width L to be 1/10- 1/1 compared to the diameter of the wafer W, and more preferably about ⅙ or greater than the diameter of the wafer W.
[0147] The separation gas nozzle 41 ( 42 ) is located in the groove portion 43 formed in the convex portion 4 and the lower ceiling surfaces 44 are located in both sides of the separation gas nozzle 41 ( 42 ) in the above embodiment. However, as shown in FIG. 20 , a conduit 47 extending along the radial direction of the rotation table 2 may be made inside the convex portion 4 , instead of the separation gas nozzle 41 ( 42 ), and plural holes 40 may be formed along the longitudinal direction of the conduit 47 so that the separation gas (N2 gas) may be ejected from the plural holes 40 in other embodiments.
[0148] As illustrated in FIG. 21A , the ceiling surface 44 of the separation areas D may not only be formed as a flat surface but may also be formed as a recess, a protrusion as illustrated in FIG. 21B , or a wave-shape as illustrated in FIG. 21C .
[0149] The heating part for heating the wafer W may not only be a heater having a resistance heating element but may also be a lamp heating element. In addition, the heater unit 7 may be located above the rotation table 2 , or above and below the rotation table 2 . Further, in a case where the reaction of the reaction gases occur at a low temperature (e.g., room temperature), no heating member need to be provided.
[0150] Examples of the layout of the process areas 91 , 92 and the separation areas D other than the above-described embodiments of the present invention are described below. FIG. 22 illustrates an example where the second reaction nozzle 32 is positioned upstream from the transfer opening 15 with respect to the rotation direction of the rotation table 2 . The same effect as the above-described embodiments of the present invention can be attained even with this layout. The separation areas D may be configured having the sector-shaped convex portion 4 divided into two sector-shaped convex portions in the circumferential direction with the separation gas nozzle 41 ( 42 ) provided therebetween. FIG. 23 illustrates a plan view of this configuration. In this case, for example, the distance between the sector-shaped convex portion 4 and the separation gas nozzle 41 ( 42 ) or the size of the sector-shaped convex portion 4 may be set to enable the separation areas D to effectively exhibit a separating effect taking the ejection flow rate of the separation gas or the ejection flow rate of the reaction gas.
[0151] In the above-described embodiment of the present invention, the first and second process areas 91 and 92 correspond to an area having a ceiling surface higher than the ceiling surface of the separation area D. However, in this embodiment, at least one of the first and second process areas 91 and 92 has ceiling surfaces that face the rotation table 2 on both sides of the gas supplying part relative to the rotation direction in the same manner as the separation area D to form a space for impeding gas from entering the space between the ceiling surfaces and the rotation table 2 and these ceiling surfaces are lower than the ceiling surfaces (second ceiling surfaces) on both sides of the separation area D relative to the rotation direction. FIG. 24 illustrates an example of this configuration. In the second process area 92 (in this example, adsorption area of O3 gas), the second reaction gas nozzle 32 is provided below the sector shaped convex portion 4 . Other than providing the second reaction gas nozzle instead of the separation gas nozzle 41 ( 42 ), the second process area 92 in this embodiment is substantially the same as the separation area D.
[0152] In this embodiment, as illustrated in FIG. 25 , in addition to providing low ceiling surfaces (first ceiling surfaces) 44 on both sides of the separation gas nozzle 41 ( 42 ) for forming narrow gaps, low ceiling surfaces are also provided on both sides of the reaction gas nozzle 31 ( 32 ), so that the ceiling surfaces are formed to be continuous. In other words, even in a case where the convex portion 4 is provided to the entire area facing the rotation table 2 , the same effect can be attained except at the areas other than the areas where the separation gas nozzle 41 ( 42 ) and the reaction gas nozzle 31 ( 32 ) are provided. From a different standpoint, this configuration has the first ceiling surfaces 44 on both sides of the separation gas nozzle 41 ( 42 ) extending to the reaction gas nozzle 31 ( 32 ). In this case, although the separation gas diffusing to both sides of the separation nozzle 41 ( 42 ) and separation gas diffusing to both sides of the reaction gas nozzle 31 ( 32 ) merge at a lower part of the convex portion 4 (narrow gap), the gases are evacuated from the evacuation port 61 ( 62 ) positioned between the separation gas nozzle 42 ( 41 ) and the reaction gas nozzle 31 ( 32 ).
[0153] In the above embodiments, the rotation shaft 22 for rotating the rotation table 2 is located in the center portion of the chamber 1 . In the above-described embodiment of the present invention, the space between the core portion 21 of the rotation table 2 and the ceiling plate 11 of the chamber 1 is purged with the separation gas. However, the chamber 1 may be configured as illustrated in FIG. 26 . In the film deposition apparatus of FIG. 26 , the bottom portion 14 of the chamber body 12 includes a housing space 100 of a driving portion and a concave portion 100 a formed on the upper surface of the center portion of the chamber 1 . A pillar 101 is placed between the bottom surface of the housing space 100 and the upper surface of the concave part 100 a at the center portion of the chamber 1 for preventing the first reaction gas (BTBAS) ejected from the first reaction gas nozzle 31 and the second reaction gas (O3) ejected from the second reaction gas nozzle 32 from being mixed through the center portion of the chamber 1 .
[0154] In addition, a rotation sleeve 102 is provided so that the rotation sleeve 102 coaxially surrounds the pillar 101 . A ring-shape rotation table 2 is provided along the rotation sleeve 102 . Further, a driving gear portion 104 , which is driven by a motor 103 , is provided in the housing space 100 . The rotation sleeve 102 is rotated by the driving gear portion 104 via a gear portion 105 formed on the outer surface of the rotation sleeve 82 . Reference numerals 106 , 107 , and 108 indicate bearings. A purge gas supplying pipe 74 is connected to a bottom part of the housing space 100 , so that a purge gas is supplied into the housing space 100 . Another purge gas supplying pipe 75 is connected to an upper part of the housing space 100 , so that a purge gas is supplied between a side surface of the concave portion 100 a and an upper edge part of the rotation sleeve 102 . Although opening parts for supplying the purge gas to the space between the side surface of the concave portion 100 a and the upper edge part of the rotation sleeve 102 are illustrated in a manner provided on two areas (one on the left and one on the right) in FIG. 26 , the number of the opening parts (purge gas supplying port) may be determined so that the purge gas from the BTBAS gas and the O3 gas in the vicinity of the rotation sleeve 102 can be prevented from being mixed.
[0155] In the embodiment illustrated in FIG. 26 , a space between the side wall of the concave portion 80 a and the upper end portion of the rotation sleeve 82 corresponds to the ejection hole for ejecting the separation gas. Thus, in this embodiment, the ejection hole, the rotation sleeve 102 , and the pillar 101 constitute the center portion area provided at a center part of the chamber 1 .
[0156] Although the two kinds of reaction gases are used in the film deposition apparatus according to the above embodiment, three or more kinds of reaction gases may be used in other film deposition apparatuses according to other embodiments of the present invention. In this case, a first reaction gas nozzle, a separation gas nozzle, a second reaction gas nozzle, a separation gas nozzle, and a third reaction gas nozzle may be arranged in this order relative to the circumferential direction of the chamber 1 , and the separation areas including respective separation nozzles may have the same configuration as those in the above-described embodiments. In this case, an evacuation channel, a pressure gage, and/or a valve may be provided in communication with each process chamber, to thereby perform the above-described adjustment of the evacuation flow rate (pressure difference between front and rear valves) in each process area.
[0157] The film deposition apparatus according to embodiments of the present invention may be integrated into a wafer process apparatus, an example of which is schematically illustrated in FIG. 27 . The wafer process apparatus includes an atmospheric transfer chamber 112 in which a transfer arm 113 is provided, load lock chambers (preparation chambers) 114 , 115 whose atmosphere is changeable between vacuum and atmospheric pressure, a vacuum transfer chamber 116 in which two transfer arms 107 a, 107 b are provided, and film deposition apparatuses 118 , 119 according to embodiments of the present invention. In addition, the wafer process apparatus includes cassette stages (not shown) on which a wafer cassette 111 is placed. The wafer cassette 111 is brought onto one of the cassette stages, and connected to a transfer in/out port provided between the cassette stage and the atmospheric transfer chamber 112 . Then, a lid of the wafer cassette 111 is opened by an opening/closing mechanism (not shown) and the wafer is taken out from the wafer cassette 111 by the transfer arm 117 . Next, the wafer is transferred to the load lock chamber 114 ( 115 ). After the load lock chamber 114 ( 115 ) is evacuated, the wafer in the load lock chamber 114 ( 115 ) is transferred further to one of the film deposition apparatuses 118 , 119 through the vacuum transfer chamber 117 by the transfer arm 107 a ( 107 b ). In the film deposition apparatus 118 ( 119 ), a film is deposited on the wafer in such a manner as described above. Because the wafer process apparatus has two film deposition apparatuses 118 , 119 that can house five wafers at a time, the ALD (or MLD) mode deposition can be performed at high throughput.
[0158] In the above-described embodiments of the present invention, in stabilizing the flow of each reaction gas in the chamber 1 , the openings of the first and second valves 65 a, 65 b provided in the evacuation channels 63 a, 63 b are adjusted so that, for example, the flow ratio F of the evacuation gas flowing inside the two evacuation channels 63 a, 63 b is equal. Alternatively, the opening of the first and second valves 65 a, 65 b may be adjusted so that the pressure difference between each of the process areas 91 , 92 becomes smaller. In this case, a film deposition apparatus and a film deposition method are described with reference to FIGS. 28-31 . In the below-described embodiments, like components are denoted by like reference numerals as for the above-described embodiments and are not further explained.
[0159] In this embodiment, as illustrated in FIG. 28 , the first and second process pressure detecting parts 66 a, 66 b provided in the evacuation channels 63 a, 63 b are for measuring the pressure of the first and second process areas 91 , 92 . In this embodiment, the first and second pressure detecting parts 67 a, 67 b do not need to be provided in the evacuation channels 63 a, 63 b.
[0160] As illustrated in FIG. 29 , instead of storing the gas flow ratio F, the pressure difference ΔP allowed between the first and second process areas 91 , 92 is stored in the memory 82 in correspondence with each recipe. In other words, in a case where the pressure difference ΔP between each process area 91 , 92 in the chamber 1 is large, the flow of gas may become unstable because reaction gas tends to flow from a high pressure area to a low pressure area via the separation area D between the process areas 91 , 92 . However, in this embodiment, the flow of gas is stabilized by restraining the pressure difference ΔP between each process area 91 , 92 to a small amount.
[0161] In this embodiment, in order to stabilize the flow of gas, the opening of the first and second valves 65 a, 65 b using nitrogen gas is adjusted before the supplying of reaction gas (Step S 13 ) as illustrated in FIG. 30 . The differences in the method of stabilizing the flow of gas or the conditions of processing with respect to the first embodiment are described below with reference to FIG. 31 . In step S 22 ′, the predetermined value P 1 of pressure P and a predetermined value ΔP 1 of the pressure difference ΔP between the first and second process areas 91 , 92 are set to be, for example, 1067 Pa (8 Torr) and 13.3 Pa (0.1 Torr) respectively. Then, in step S 24 , the process pressure inside the chamber 1 is adjusted by adjusting the opening of the first valve 65 a so that the value detected by the process pressure detecting part 66 a becomes the predetermined value P 1 . Then, in step S 25 ′, it is determined whether the pressure difference ΔP is equal to or less than the predetermined value P 1 according to the measured (detected) results of the process pressure detecting parts 66 a, 66 b. In a case where the pressure difference ΔP becomes equal to or less than the predetermined value P 1 , the operation proceeds to the film deposition process of step S 14 . In a case where the pressure difference ΔP is greater than ΔP 1 , the opening of the second valve 65 b is adjusted so that the pressure difference ΔP becomes equal to or less than the predetermined value ΔP 1 (Step S 26 ). Then, in a case where the process pressure becomes the predetermined value P 1 , the thin film deposition is initiated (Step S 27 ). In a case where the process pressure does not become the predetermined value P 1 , the processes of steps S 24 -S 27 are repeated when the repletion time t 1 elapses (Step S 28 ), when the pressure difference ΔP becomes equal to or less than the predetermined value P 1 in Step S 25 , or when the process pressure reaches the predetermined value P 1 in Step S 27 .
[0162] Then, in performing the film deposition process where gas is switched from N2 gas to reaction gas, the flow of gas (BTBAS gas, O3 gas) becomes stable owing to the pressure difference ΔP between the process areas 91 , 92 being equal to or less than the predetermined value ΔP 1 by the step S 21 -S 28 or the pressure difference ΔP between the process areas 91 , 92 being substantially close to the predetermined value ΔP 1 . Therefore, the adsorption of BTBAS gas can be stabilized and the oxide reaction of the adsorbed molecules of O3 gas can be stabilized. As a result, the wafer W can obtain a satisfactory thin film having an even film thickness with respect to an in-plane direction or in-between surfaces of the wafer W.
[0163] Furthermore, because bias of evacuation on both sides of the separation areas D can be prevented, BTBAS gas and O3 gas can be prevented from passing through the separation areas and become mixed. Accordingly, reaction products can be prevented from being formed on areas besides the surface of the wafers W. Thus, formation of particles can be prevented. Further, because the pressure difference ΔP between the first and second process chambers 91 , 92 can be reduced to a low value, a buoyancy of gases rising from the rotation table 2 hardly occurs, for example, when the wafer W enters the process area 91 ( 92 ) or when the wafer W exits the process area 91 ( 92 ) by the rotation of the rotation table 2 . Accordingly, the wafer W can be prevented from floating from the concave portion 24 or deviating from the concave portion 24 . Thus, the wafer W can be prevented from colliding with the ceiling plate 11 and problems can be prevented from occurring in the film deposition process.
[0164] Further, even in a case where there is difference in the gas flow (conductance) between the first and second process areas 91 , 92 due to the size difference between the areas (first and second process areas 91 , 92 ) in which the gases flow or influence the concave portion 24 formed in the rotation table 2 , the difference in the conductance of the gas flow can be restrained and the flow of gas can be positively stabilized because the pressure difference ΔP between the first and second process areas 91 , 92 is restrained to a low value.
[0165] In the above-described embodiments of the present invention, in measuring (detecting) the pressure of the first and second process areas 91 , 92 , the process pressure detecting parts 66 a, 66 b are provided to the evacuation channels 63 a, 63 b. Alternatively, the process pressure detecting parts 66 a, 66 b in other areas pressure communicating with the first and second process areas 91 , 92 (e.g., sidewall of the chamber 1 ). Further, in adjusting the pressure of each process area 91 , 92 , the number of rotations R of the evacuation pump 64 may be adjusted along with adjusting the opening of the first and second valves 65 a, 65 b. Further, the two evacuation pumps 64 a and 64 b may be shared (integrated). Further, although the pressure detection value of the process pressure detecting part 66 a is used in setting the process pressure in the chamber 1 to the predetermined value P 1 according to the above-described embodiments of the present invention, the pressure detection value of the process pressure detecting part 66 a may alternatively be used. Further, a pressure value detected from another pressure detecting part provided in the chamber 1 may serve as the pressure value used to set the process pressure in the chamber 1 to the predetermined value P 1 .
[0166] In the above-described embodiments, the pressure of the first and second process areas 91 , 92 are adjusted instead of the flow ratio F of the evacuation gas for stabilizing gas flow. However, both the flow rate of the evacuation gas and the pressure of the first and second process areas 91 , 92 may be adjusted. For example, in a case where there is a high possibility of pressure changing inside the chamber 1 , pressure in each process area 91 , 92 is adjusted when starting the supply of reaction gas into the chamber 1 (when switching from N2 gas to reaction gas in Step S 14 and then, the flow ratio F of the evacuation gas is adjusted when a predetermined time elapses after starting a film deposition process. In this case, the flow of gas flowing into the chamber 1 can be further stabilized and the buoyancy of the wafer W can be restrained.
Third Embodiment
[0167] In the following embodiment of the present invention, a vacuum chamber having a rotation table includes a first process area to which a first reaction gas is supplied and a second process area in which a second reaction gas is supplied. Further, the first and second process areas are separated from each other in a rotation direction of the rotation table. Further, separation areas are interposed between the first and second process areas for supplying separation gas between the first and second process areas from a separation gas supplying part. A thin film deposition process is performed by rotating a rotation table having plural substrates arranged in a rotation direction and layering plural layers of reaction products with first and second reaction gases. Evacuation is performed with a first evacuation channel having an evacuation port positioned between the first process area and the separation area positioned adjacent to the first process area and located downstream of the first process area relative to the rotation direction when viewed from the rotation center of the rotation table and a second evacuation channel having an evacuation port positioned between the second process area and the separation area positioned adjacent to the second process area and located downstream of the second process area relative to the rotation direction when viewed from the rotation center of the rotation table. The evacuation system (evacuation channel, pressure control device, evacuation part) of each of the process areas is independent from the other. Accordingly, in performing the thin film deposition process, the first and second reaction gases do not mix in the evacuation systems. Therefore, the possibility of reaction products being generated in the evacuation systems is extremely low.
[0168] Further, a ceiling surface is provided on both sides of a separation gas supplying part for forming a narrow space that allows the separation gas to flow from the separation areas towards the process areas. Thereby, reaction gases are prevented from entering separation areas. Further, a center portion area, which is positioned at a center portion inside the chamber for separating the atmosphere of the first and second process areas, includes an ejection port that ejects separation gas towards a substrate receiving surface of the rotation table for ejecting the separation gas towards the circumferential edges of the rotation table. As a result, with the center portion area disposed in-between, different reaction gases can be prevented from mixing with each other. Accordingly, a satisfactory film deposition process can be achieved. Further, generation of particles can be prevented because no reaction products or very few reaction products are formed.
[0169] Referring to FIG. 32 , which is a cut-away diagram taken along I-I′ line in FIG. 34 , a film deposition apparatus according to an embodiment of the present invention has a vacuum chamber 201 having a flattened cylinder shape, and a rotation table 202 that is located inside the chamber 201 and has a rotation center at a center of the vacuum chamber 201 . The vacuum chamber 201 is made so that a ceiling plate 211 can be separated from a chamber body 212 . The ceiling plate 211 is pressed onto the chamber body 212 via a ceiling member such as an O-ring 213 , so that the vacuum chamber 201 is hermetically sealed. On the other hand, the ceiling plate 211 can be raised by a driving mechanism (not shown) when the ceiling plate 211 has to be removed from the chamber body 212 .
[0170] The rotation table 202 is fixed onto a cylindrically shaped core portion 221 . The core portion 221 is fixed on a top end of a rotational shaft 222 that extends in a vertical direction. The rotational shaft 222 penetrates a bottom portion 214 of the vacuum chamber 201 and is fixed at the lower end to a driving mechanism 223 that can rotate the rotational shaft 222 clockwise, in this embodiment. The rotation shaft 222 and the driving mechanism 223 are housed in a cylindrical case body 220 having an open upper surface. The case body 220 is hermetically fixed to a bottom surface of the bottom portion 214 via a flanged portion, which isolates an inner environment of the case body 220 from an outer environment.
[0171] As shown in FIGS. 33 and 34 , plural (five in the illustrated example) circular concave portions 224 , each of which receives a semiconductor wafer W, are formed along a rotation direction (circumferential direction) in a top surface of the rotation table 202 , although only one wafer W is illustrated in FIG. 34 . FIGS. 35A and 35B are expanded views of the rotation table 202 being cut across and horizontally expanded along its concentric circle. As shown in FIG. 35A , the concave portion 224 has a diameter slightly larger, for example, by 4 mm than the diameter of the wafer W and a depth equal to a thickness of the wafer W. Therefore, when the wafer W is placed in the concave portion 224 , a surface of the wafer W is at the same elevation of a surface of the rotation table 202 (an area of the rotation table where the wafer W is not placed). If there is a relatively large difference in height between the surface of the wafer W and the surface of the rotation table 202 , a change of pressure occurs at the portion where the difference is located. Therefore, from the aspect of attaining uniformity of film thickness in the in-plane direction, it is preferable to match the elevation of the surface of the wafer W and the elevation of the surface of the rotation table 202 . While matching the elevation of the surface of the wafer W and the height of the surface of the rotation table 202 may signify that the height difference of the surfaces of the wafer W and the rotation table is less than or equal to approximately 5 mm, the difference has to be as close to zero as possible to the extent allowed by machining accuracy. In the bottom of the concave portion 224 there are formed three through holes (not shown) through which three corresponding elevation pins are raised/lowered. The elevation pins support a back surface of the wafer W and raises/lowers the wafer W.
[0172] The concave portions 224 are substrate receiving areas (wafer W receiving areas) provided to position the wafers W and prevent the wafers W from being thrown outwardly by the centrifugal force caused by rotation of the rotation table 202 . However, the wafer W receiving areas are not limited to the concave portions 224 , but may be performed by guide members that are provided along a circumferential direction on the surface of the rotation table 202 to hold the edges of the wafers W. In a case where the rotation table 202 is provided with a chuck mechanism (e.g., electrostatic chucks) for attracting the wafer W, the areas on which the wafers W are received by the attraction serve as the substrate receiving areas.
[0173] Referring again to FIGS. 33 and 34 , the chamber 201 includes a first reaction gas nozzle 231 , a second reaction gas nozzle 232 , and separation gas nozzles 241 , 242 above the rotation table 202 , all of which extend in radial directions and are arranged at predetermined angular intervals in a circumferential direction of the chamber 201 . With this configuration, the concave portions 224 can move through and below the nozzles 231 , 232 , 241 , and 242 . In the illustrated example, the second reaction gas nozzle 232 , the separation gas nozzle 241 , the first reaction gas nozzle 231 , and the separation gas nozzle 242 are arranged clockwise in this order. These gas nozzles 231 , 232 , 241 , and 242 penetrate the circumferential wall portion of the chamber body 212 and are supported by attaching their base ends, which are gas inlet ports 231 a, 232 a, 241 a, 242 a, respectively, on the outer circumference of the wall portion.
[0174] Although the gas nozzles 231 , 232 , 241 , 242 are introduced into the chamber 201 from the circumferential wall portion of the chamber 201 in the illustrated example, these nozzles 231 , 232 , 241 , 242 may be introduced from a ring-shaped protrusion portion 205 (described later). In this case, an L-shaped conduit may be provided in order to be open on the outer circumferential surface of the protrusion portion 205 and on the outer top surface of the ceiling plate 211 . With such an L-shaped conduit, the nozzle 231 ( 232 , 241 , 242 ) can be connected to one opening of the L-shaped conduit inside the chamber 201 and the gas inlet port 231 a ( 232 a, 241 a, 242 a ) can be connected to the other opening of the L-shaped conduit outside the chamber 201 .
[0175] The reaction gas nozzle 231 is connected to a gas supply source (not illustrated) of a first reaction gas (e.g., BTBAS gas) and the reaction gas nozzle 232 is connected to a gas supply source (not illustrated) of a second reaction gas (e.g., O3 gas). Further, the reaction gas nozzles 241 and 242 are each connected to a gas supply source (not illustrated) of N2 gas. Further, the reaction gas nozzles 231 , 232 are also connected to a gas supply source (not illustrated) of N2 for supplying N2 gas to each process area 200 P 1 , 200 P 2 as a pressure adjustment gas when operation of the film deposition apparatus is initiated. In this embodiment, the second reaction gas nozzle 232 , the separation gas nozzle 241 , the first reaction gas nozzle 231 , and the separation gas nozzle 242 are arranged in this order in a clockwise direction.
[0176] The reaction gas nozzles 231 , 232 have ejection holes 233 facing directly downward for ejecting reaction gases below. The ejection holes 233 are arranged at predetermined intervals in longitudinal directions of the reaction gas nozzles 231 , 232 . The separation gas nozzles 241 , 242 have ejection holes 240 facing directly downward for ejecting reaction gases below. The ejection holes 233 are arranged at predetermined intervals in longitudinal directions of the reaction gas nozzles 231 , 232 . The reaction gas nozzle 231 corresponds to a first reaction gas supplying part and the reaction gas nozzle 232 corresponds to a second reaction gas supplying part. The area below the first reaction gas supplying part corresponds to a first process area 200 P 1 for enabling BTBAS gas to be adsorbed to the wafer W. The area below the second reaction gas supplying part corresponds to a second process area 200 P 2 for enabling O3 gas to be adsorbed to the wafer W.
[0177] The separation gas nozzles 241 , 242 are provided in separation areas 200 D that are configured to separate the first process area 200 P 1 and the second process area 200 P 2 . As shown in FIGS. 33 through 35B , in each of the separation areas 200 D, a convex portion 204 is provided in a ceiling plate 211 of the chamber 201 in a manner protruding downwards. The convex portion 204 has a top view shape of a sector. The convex portion 204 is formed by dividing a circle depicted along an inner circumferential wall of the chamber 201 . The circle has the rotation center of the rotation table 202 as its center. The convex portion 204 has a groove portion 243 provided at the circumferential center of the circle that extends in the radial direction of the circle. The separation gas nozzle 241 ( 242 ) is located in the groove portion 243 . The distance between the center axis of the separation gas nozzle 241 ( 242 ) and one side of the sector-shaped convex portion 204 (edge of the convex portion 204 towards an upstream side relative to relative to a rotation direction of the rotation table 202 ) is substantially equal to the distance between the center axis of the separation gas nozzle 241 ( 242 ) and the other side (edge of the convex portion 204 towards a downstream side relative to the rotation direction of the rotation table 202 ) of the sector-shaped convex portion 204 .
[0178] It is to be noted that, although the groove portion 243 is formed in a manner bisecting the convex portion 204 in this embodiment, the groove portion 242 may be formed so that an upstream side of the convex portion 204 relative to the rotation direction of the rotation table 202 is wider, in other embodiments.
[0179] Accordingly, in this embodiment, a flat low ceiling surface (first ceiling surface) 244 is provided as a lower surface of the convex portion 204 on both sides of the separation gas nozzle 241 ( 242 ) relative to the rotation direction of the rotation table 202 . Further, a high ceiling surface (second ceiling surface) 245 , which is positioned higher than the first ceiling surface 244 , is provided on both sides of the separation gas nozzle 241 ( 242 ) relative to the rotation direction of the rotation table 202 . The role of the convex portion 204 is to provide a separation space which is a narrow space between the convex portion 204 and the rotation table 202 for impeding the first and second reaction gases from entering the narrow space and preventing the first and second reaction gases from being mixed.
[0180] Taking the separation gas nozzle 241 as an example, the O3 gas from an upstream side of the rotation direction of the rotation table 202 is impeded from entering the space between the convex portion 204 and the rotation table 202 . Further, the BTBAS gas from a downstream side of the rotation direction of the rotation table 202 is impeded from entering the space between the convex portion 204 and the rotation table 202 . “Impeding the first and second reaction gases from entering” signifies that the N2 gas ejected as the separation gas from the separation gas nozzle 241 diffuses between the first ceiling surfaces 244 and the upper surfaces of the rotation table 202 and flows out to a space below the second ceiling surfaces 245 , which are adjacent to the corresponding first ceiling surfaces 244 in the illustrated example, so that the gases cannot enter the separation space from the space below the second ceiling surfaces 245 . “The gases cannot enter the separation space” not only signifies that the gases from the adjacent space below the second ceiling surfaces 245 are completely prevented from entering the space below the convex portion 204 , but that the gases from both sides cannot proceed farther toward the space below the convex portion 204 and thus be mixed with each other. Namely, as long as such effect can be attained, the separation area 200 D can achieve the role of separating the first process area 291 and the second process area 292 . The narrowness of the narrow space is set so that the pressure difference between the narrow space (space below the convex portion 204 ) and the space adjacent to the narrow space (e.g., space below the second ceiling surface 245 ) is large enough to attain the effect of “the gases cannot enter the separation space”. The specific measurements of the narrow space differs depending on, for example, the area of the convex portion 204 . Further, the gases adsorbed on the wafer W can pass through below the convex portion 204 . Therefore, “impeding the first and second reaction gases from entering” signifies that the first and second reaction gases are in a gaseous phase.
[0181] As illustrated in FIGS. 36 and 38 , a protrusion portion 205 is provided on a lower surface of the ceiling plate 211 so that the inner circumference of the protrusion portion 205 faces the outer circumference of the core portion 221 . The protrusion portion 205 opposes the rotation table 202 at an outer area of the core portion 221 . In addition, a lower surface of the protrusion portion 205 and a lower surface of the convex portion 204 form one plane surface. In other words, a height of the lower surface of the protrusion portion 205 from the rotation table 202 is the same as a height of the lower surface (ceiling surface 244 ) of the convex portion 204 . FIGS. 33 and 34 show the ceiling plate 211 being horizontally cut across an area including a portion substantially lower than the ceiling surface 245 but higher than the separation nozzles 241 , 242 . The convex portion 204 may not only be formed integrally with the protrusion portion 205 but may also be formed separately from the protrusion portion 205 .
[0182] The configuration of the combination of the convex portion 204 and the separation nozzle 241 ( 242 ) is fabricated by forming the groove portion 243 in a sector-shaped plate to be the convex portion 204 , and locating the separation gas nozzle 241 ( 242 ) in the groove portion 243 in the above embodiment. However, two sector-shaped plates may be attached on the lower surface of the ceiling plate 211 by screws so that the two sector-shaped plates are located on both sides of the separation gas nozzle 241 ( 242 ).
[0183] In this embodiment, the separation gas nozzles 241 ( 242 ) has ejection holes arranged at predetermined intervals (e.g., about 10 mm) in longitudinal directions of the separation gas nozzles 241 , 242 . The ejection holes have an inner diameter of about 0.5 mm, for example.
[0184] In this embodiment, a wafer W having a diameter of about 300 mm is used as the target substrate. In this embodiment, at an area spaced about 140 mm from the rotation center of the rotation table 202 in the outer circumferential direction (border part between the convex portion 204 and the below-described convex portion 205 ), the convex portion 204 includes a part where the length is about 146 mm in the circumferential direction (length of arc concentric with the rotation table 202 ). Further, at an area corresponding to an outermost part of the wafer W receiving area (concave part 224 ), the convex portion includes a part where the length is about 502 mm in the circumferential direction. In the outermost part as illustrated in FIG. 35A , the length L of convex portion 204 on each side of the separation nozzle 241 ( 42 ) with respect to the circumferential direction is about 246 mm.
[0185] As illustrated in FIG. 35B , the height from a top surface of the rotation table 202 to the lower surface of the convex portion 204 (i.e. first ceiling surface 244 ) is indicated as “h”. The height h ranges from, for example, about 0.5 mm to 10 mm, and more preferably, about 4 mm. In this case, the number of rotations of the rotation table 202 is set to, for example, about 1 rpm-500 rpm. Accordingly, in order to attain a separating function at the separation area 200 D, the size of the convex portion 204 and the height h from the surface of the rotation table 202 to the lower surface of the convex portion 204 (first ceiling surface 244 ) are to be set based on, for example, experimentation of the applicable range of the number of rotations of the rotation table 202 . Not only nitrogen gas (N2) may be used as the separation gas but also inert gas such as argon (Ar) may be used. Further, other gases such as hydrogen (H 2 ) maybe used. As long as the film deposition process is not affected, the kind of gas is not to be limited in particular.
[0186] As described above, the lower surface of the ceiling plate 211 of the chamber 201 (i.e. ceiling when viewed from the wafer receiving area (concave portion 224 ) of the rotation table 202 includes the first ceiling surface 244 and the second ceiling surface 245 provided in a circumferential direction in a manner where the second ceiling surface 245 is positioned higher than the first ceiling surface 245 . FIG. 32 is a vertical cross-sectional view of an area having a high ceiling surface 245 . FIG. 36 is a vertical cross-sectional view of an area having a low ceiling surface 244 . The convex portion 204 has a bent portion 246 that bends in an L-shape at the outer circumferential edge of the convex portion 204 (area at the outer rim of the chamber 201 ). The sector-shaped convex portion 204 is provided towards the ceiling plate 211 and is configured to be detachable from the chamber body 212 . Therefore, a slight gap(s) is provided between the outer peripheral surface of the bent portion and the chamber body 212 . Like the convex portion 204 , the bent portion 246 is also provided for impeding reaction gases from entering and preventing the reaction gases from mixing. The gaps between the bent portion 246 and the rotation table 202 and between the bent portion 246 and the chamber body 212 are set to have substantially the same measurements as the height h of the ceiling surface 244 with respect to the surface of the rotation table 202 . In this embodiment, from the standpoint of the surface of the rotation table 202 , the inner surface of the bent portion 246 serves as an inner circumferential wall of the chamber 201 .
[0187] As illustrated in FIG. 36 , the chamber body 212 has an inner circumferential wall formed as a vertical surface in the vicinity of the outer circumferential surface of the bent portion 246 in the separation area 200 D. As illustrated in FIG. 36 , in an area other than the separation area 200 D, the chamber body 212 has a dented portion (dented towards the outer side) that is notched having a rectangular cross section. The dented portion faces, for example, an area extending from the outer circumferential surface of the rotation table 202 to a bottom surface part 214 . In the dented portion, the areas communicating with the first and second process areas 200 P 1 , 200 P 2 are referred to as first and second evacuation areas 200 E 1 and 200 E 2 , respectively. Accordingly, as illustrated in FIGS. 32 and 34 , first and second evacuation ports 261 and 262 are formed at corresponding bottom parts of the first and second evacuation areas 200 E 1 and 200 E 2 .
[0188] The first and second evacuation ports 261 and 262 are provided for ensuring a separating effect in the separation area 200 D. When viewing the first and second evacuation ports 261 , 262 from a plan position, the first and second evacuation ports 261 , 262 are provided on both sides of the separation area 200 D in the rotation direction. Each of the evacuation ports 261 , 262 is dedicated to evacuate a corresponding reaction gas (BTBAS gas and O3 gas). In this example, the first evacuation port 261 is formed between the first reaction gas nozzle 231 and the separation area 200 D provided adjacent to the first reaction gas nozzle 231 towards the downstream side of the first reaction gas nozzle 231 with respect to the rotation direction. Further, the second evacuation port 262 is formed between the second reaction gas nozzle 232 and another separation area 200 D provided adjacent to the second reaction gas nozzle 232 towards the downstream side of the second reaction gas nozzle 232 .
[0189] In other words, as illustrated in FIG. 34 , the first evacuation port 261 of the first evacuation channel 263 a is provided between the first process area 200 P 1 and the separation area 200 D provided towards the downstream side of the first process area 200 P 1 with respect to the rotation direction (corresponding to area covered by the convex portion 204 at which the separation gas nozzle 242 is provided in FIG. 34 ). That is, in FIG. 34 , the first evacuation port 261 is positioned between a straight line L 1 (passing through the center of the rotation table 202 and the first process area 200 P 1 ) and a straight line L 2 (passing through the center of the rotation table 202 and an upstream edge of the separation area 200 D provided towards the downstream side of the first process area 200 P with respect to the rotation direction). The second evacuation port 262 of the second evacuation channel 263 b is provided between the second process area 200 P 2 and the separation area 200 D provided towards the downstream side of the second process area 200 P 2 with respect to the rotation direction (corresponding to area covered by the convex portion 204 at which the separation gas nozzle 241 is provided in FIG. 34 ). That is, in FIG. 34 , the second evacuation port 262 is provided between a straight line L 3 (dash-double-dot line passing through the center of the rotation table 202 and the second process area 200 P 2 ) and a straight line L 4 (dash-double-dot line passing through the center of the rotation table 202 and an upstream edge of the separation area 200 D provided towards the downstream side of the second process area 200 P 2 with respect to the rotation direction).
[0190] The evacuation ports 261 , 262 may be located at a part other than the bottom portion of the chamber 201 . For example, the evacuation ports 261 , 262 may be located in the side wall of the chamber 201 . In addition, when the evacuation ports 261 , 262 are provided in the side wall of the chamber 201 , the evacuation ports 261 , 262 may be located higher than the rotation table 202 . In this case, the gases above the rotation table 202 flow towards the outer side of the rotation table 202 . Therefore, it is advantageous in that particles are not blown upward by the gases, compared to evacuating from the ceiling surface facing the rotation table 202 .
[0191] As illustrated in FIG. 32 , the first evacuation port 261 is connected to a vacuum pump 264 a via a first evacuation channel 263 a. For example, the vacuum pump 264 a is connected to a mechanical booster pump and a dry pump. A first pressure adjusting part 265 a is interposed between the first evacuation port 261 and the vacuum pump 264 a. Although not illustrated in the drawings, the first pressure adjusting part 265 a has, for example, a pressure adjustment valve including a butterfly valve, a motor for opening/closing the pressure adjustment valve, and a controller for controlling operation of the motor. For example, the first pressure adjusting part 265 a is configured as an APC (Auto Pressure Controller) that can perform pressure adjustment based on a detection result from a pressure gage 266 a connected to the evacuation channel 263 a provided upstream of the first pressure adjusting part 265 a. In this embodiment, the vacuum pump 264 a corresponds to a first evacuation part. In the following, the first evacuation channel 263 a, the first pressure adjusting part 265 a, and the vacuum pump 264 a as a whole may be referred to as a first evacuation system.
[0192] The pressure gage 266 a is for measuring the pressure in the first process area 200 P 1 in the chamber (upstream side of the evacuation channel 263 a ). The first pressure adjusting part 265 a serves to maintain the first process area 200 P 1 in a steady pressure atmosphere by adjusting pressure based on a detection result of the pressure gage 266 a.
[0193] Likewise, the second evacuation port 262 is connected to, for example, a vacuum pump (second evacuation part) 264 b via a second evacuation channel 263 b. A second pressure adjusting part 265 b is interposed between the second evacuation port 262 and the vacuum pump 264 b for maintaining the second process area 200 P 2 in a steady pressure atmosphere. The second pressure adjusting part 265 b enables evacuation to be performed independently from the first evacuation channel 263 a. The second pressure adjusting part 265 b is also configured as an APC (Auto Pressure Controller) that can perform pressure adjustment based on a detection result from a pressure gage 266 b connected to the evacuation channel 263 b provided upstream of the second pressure adjusting part 265 b. In the following, the second evacuation channel 263 b, the second pressure adjusting part 265 b, and the vacuum pump 264 b as a whole may be referred to as a second evacuation system. Further, as illustrated in FIG. 40 , first and second detoxifiers 267 a, 267 b may be provided at each downstream side of the evacuation pumps 264 a, 264 b for separately detoxifying ejected matter ejected from each of the vacuum pumps 264 a, 264 b.
[0194] As shown in FIGS. 32 and 37 , a heater unit (heating portion) 207 is provided in a space between the bottom portion 214 of the chamber 201 and the rotation table 202 , so that the wafers W placed on the rotation table 202 are heated through the rotation table 202 at a temperature determined by a process recipe. A cover member 271 is provided beneath the rotation table 202 near the outer circumference of the rotation table 202 in a manner surrounding the entire circumference of the heater unit 207 , so that the atmosphere where the heater unit 207 is located is partitioned from the atmosphere extending from the upper space of the rotation table 202 to the evacuation areas 200 E 1 , 200 E 2 . The cover member 271 has an upper edge that is bent outward to form a flange shape. Thereby, gas can be prevented from entering the cover member 271 from the outside by reducing the size of the gap between the bent upper edge and a lower surface of the rotation table 202 .
[0195] At an area located towards the bottom portion 214 and more towards the rotation center than the space where the heater unit 207 is provided, narrow spaces are provided in the vicinity of the center of the lower surface of the rotation table 202 and the core portion 221 . Further, slight gaps, which are provided at a penetration hole through which the rotation shaft 222 passes, are in pressure communication with the inside of the case body 220 . A purge gas supplying pipe 272 is connected to the case body for supplying a purge gas such as N2 gas to the aforementioned narrow spaces. Purge gas supplying pipes 273 are connected to plural areas in the circumferential direction at the bottom portion of the chamber 201 for purging the space where the heater unit 207 is provided.
[0196] By providing the purge gas supplying pipes 272 , 273 , N2 gas is purged into the space extending from the inside of the case body 220 to the area where the heater unit 207 is provided. The purge gas is evacuated from the gap between the rotation table 202 and the cover member 271 to the evacuation ports 261 , 262 via an evacuation area 200 E. Accordingly, because the BTBAS gas or O3 gas is prevented from circling around from one side of the first process area 200 P 1 and the second process area 200 P 2 to the other side of the first process area 200 P 1 and the second process area 200 P 1 via a lower part of the rotation table 202 , the purge gas plays the role of a separation gas.
[0197] A gas separation supplying pipe 251 is connected to the top center portion of the ceiling plate 211 of the chamber 201 , so that N2 gas is supplied as a separation gas to a space 252 between the ceiling plate 211 and the core portion 221 . The separation gas, which is supplied to the space 252 , is ejected towards the circumferential edges through the thin gap 250 between the protrusion portion 205 and the rotation table 202 and then along the wafer receiving area of the rotation table 202 . Because the separation gas fills the space surrounded by the protrusion portion 205 , reaction gases (BTBAS gas or O3 gas) can be prevented from mixing via the center portion of the rotation table 202 between the first process area 200 P 1 and the second process area 200 P 2 . That is, the film deposition apparatus according to this embodiment is divided into a rotation center portion of the rotation table 200 and the chamber 201 for separating the atmosphere between the first process area 200 P 1 and the second process area 200 P 2 . Further, the film deposition apparatus according to this embodiment is provided with a center area 200 C having an ejection opening formed along a rotation direction at the center portion of the rotation table 202 for ejecting the separation gas on the surface of the rotation table 202 . The ejection opening corresponds to the narrow gap 250 between the protrusion portion 205 and the rotation table 202 .
[0198] As illustrated in FIGS. 33 , 34 , and 39 , a transfer opening 215 is formed in a side wall of the chamber 201 for transferring a wafer W between an outside transfer arm 210 and the rotation table 202 . The transfer opening 215 is provided with a gate valve (not illustrated) by which the transfer opening 215 is opened or closed. When a concave portion (wafer receiving area) 224 of the rotation table 202 is in alignment with the transfer opening 215 , the wafer W is transferred into the chamber 201 and placed in the concave portion 224 as a wafer receiving portion of the rotation table 202 from the transfer arm 210 . In order to lower/raise the wafer W into/from the concave portion 224 , there are provided elevation pins 216 that are raised or lowered through corresponding through holes formed in the concave portion 224 of the rotation table 202 by an elevation mechanism (not illustrated).
[0199] As illustrated in FIGS. 32 and 34 , the film deposition apparatus according to an embodiment of the present invention includes a control part 200 including a computer for controlling overall operations of the film deposition apparatus. A program for causing operation of the film deposition apparatus is stored in a memory of the control part 200 . This program includes a group of steps for performing the below-described operation by the film deposition apparatus. This program may be installed to the control part 200 from a storage medium such as a hard disk, a compact disk, a magneto-optical magnetic disk, a memory card, or a flexible disk.
[0200] As illustrated in FIG. 32 , the control part 200 is connected to the above-described first and second pressure adjusting parts 265 a and 265 b. For example, a predetermined pressure value of the controller for each pressure adjusting part 265 a, 265 b can be set based on data input from a control terminal (not illustrated) by the user or data set in the memory beforehand. Further, the detection results of the pressure gages 266 a, 266 b are also output to the control part 200 .
[0201] Next, a film deposition method according to an embodiment of the present invention is described. The gate valve (not illustrated) is opened, and a wafer W is transferred into the concave portion 224 of the rotation table 202 from outside via the transfer opening 215 by the transfer arm 202 . The transfer is performed by raising or lowering the elevation pins 216 from the bottom portion of the chamber 201 via the through holes formed at the bottom surface of the concave portion 224 as illustrated in FIG. 39 . In this example, the transfer is performed by intermittently rotating the rotation table 202 and placing wafers W on five corresponding concave portions 224 of the rotation table 202 . Then, each of the process areas 200 P 1 and 200 P 2 is evacuated to a predetermined pressure by activating the vacuum pumps 264 a, 264 b and fully opening the pressure adjustment valves of the first and second pressure adjusting parts 265 a, 265 b. Further, the wafer W is heated with the heater unit 207 by rotating the rotation table 202 in a clockwise direction. For example, the rotation table 202 is heated to a temperature of approximately 300° C. with the heater unit 207 beforehand, and then the wafer W is heated by being placed on the rotation table 202 .
[0202] Along with the heating of the wafer W, the pressure inside the chamber 201 is adjusted by supplying N2 gas into the chamber 201 in an amount substantially equal to the amount of reaction gas, separation gas, and purge gas supplied into the chamber 201 after a film deposition process is started. For example, the first reaction gas nozzle 231 supplies N2 gas at a flow rate of 100 sccm, the second gas nozzle 232 supplies N2 gas at a flow rate of 10,000 sccm, separation gas nozzles 241 , 242 each supplies N2 gas at a flow rate of 20,000 sccm, and the separation gas supplying pipe 251 supplies N2 gas at a flow rate of 5,000 sccm into the chamber 201 . Then, the first and second pressure adjusting parts 265 a, 265 b perform opening/closing of the pressure adjustment valves so that the pressure inside the process areas 200 P 1 , 200 P 2 become the predetermined pressure value, such as 1,067 Pa (8 Torr). It is to be noted that a predetermined amount of N2 gas is also supplied from each purge gas supplying pipe 272 , 273 .
[0203] Then, it is determined whether the temperature of the wafer W has reached a predetermined temperature by a temperature sensor (not illustrated) and whether the pressure P in each of the first and second process areas 200 P 1 , 200 P 2 is a predetermined pressure. Then, the gases supplied from the first and second reaction gas nozzles 231 , 232 are switched from N2 gas to BTBAS gas and O3 gas, respectively. Thereby, the film deposition process is performed on the wafer W. The switching of the gases of each of the first and second reaction gas nozzle 231 , 232 is preferably performed slowly in order to prevent the total flow rate of gas supplied to the chamber 201 from steeply changing.
[0204] Because the wafers W alternatively pass through the first and second process areas 200 P 1 , 200 P 2 by the rotation of the rotation table 202 , BTBAS gas is adsorbed to the wafer W and then O3 is adsorbed to the wafer W. Thereby, one or more layers of silicon oxide are formed on the wafer W. Accordingly, a silicon oxide film having a predetermined film thickness can be deposited by forming molecular layers of silicon oxide.
[0205] In this case, N2 gas is also supplied as a separation gas from the gas separation supplying pipe 51 . Thereby, N2 gas is ejected along the surface of the rotation table 202 from the center portion area 200 , that is, the area between the protrusion portion 5 and the center portion of the rotation table 2 . As described above, a wide area is provided by cutting out (notching) the inner circumferential wall of the chamber body 212 provided at a lower side of the second ceiling surface 245 .
[0206] A gas separation supplying pipe 51 is connected to the top center portion of the ceiling plate 11 of the chamber 1 , so that N2 gas is supplied as a separation gas to a space 52 between the ceiling plate 11 and the core portion 21 . The separation gas, which is supplied to the space 52 , is ejected towards the circumferential edges through the thin gap 50 between the protrusion portion 5 and the rotation table 2 and then along the wafer receiving area of the rotation table 2 . Because the separation gas fills the space surrounded by the protrusion portion 5 , reaction gases (BTBAS gas or O3 gas) can be prevented from mixing via the center portion of the rotation table 2 between the first process area 91 and the second process area 92 . That is, the film deposition apparatus according to this embodiment is divided into a rotation center portion of the rotation table 2 and the chamber 1 for separating the atmosphere between the first process area 91 and the second process area 92 . Further, the film deposition apparatus according to this embodiment is provided with a center area C having an ejection opening formed along a rotation direction at the center portion of the rotation table 2 for ejecting the separation gas on the surface of the rotation table 2 . The ejection opening corresponds to the narrow gap 50 between the protrusion portion 5 and the rotation table 2 . The evacuation ports 261 , 262 are provided below this wide space. Accordingly, the pressure in the space below the second ceiling surface 245 is lower than the pressure in the narrow space below the first ceiling surface 244 and lower than the pressure in the center portion area 200 C. FIG. 41 schematically illustrates the state of the flow of gases ejected from respective parts. The O3 gas being ejected to a lower side from the second reaction gas nozzle 232 , contacts the surface of the rotation table 202 (both the surface of the wafer W and the surface of non-receiving area) and flows upstream relative to the rotation direction along the surfaces. Such O3 gas is evacuated from the evacuation port 262 by flowing to the evacuation area 200 E 2 between the circumferential edge of the rotation table 202 and the inner circumferential wall of the chamber 201 as the O3 gas is forced back by the N2 gas flowing from the upstream side.
[0207] Further, O3 gas being ejected to a lower side from the second reaction gas nozzle 232 flows toward the evacuation port 262 by the flow of N2 gas ejected from the center portion area 200 C and the drawing effect of the evacuation port 262 . However, a portion of the O3 gas flows downstream to a separation area 200 D and into a lower part of the sector-shaped convex portion 204 . Nevertheless, because the height of the ceiling surface 244 of the convex portion 204 and the length of the ceiling surface 244 of the convex portion 204 are set with measurements for preventing gas from flowing to a lower part of the ceiling surface 244 in a case where process parameters during operation (e.g., flow rate of each gas) are used, O3 gas can hardly flow into the lower part of the sector-shaped convex portion 204 or cannot reach the vicinity of the separation gas nozzle 241 . Accordingly, the O3 gas is forced back toward the upstream side relative to the rotation direction (i.e. toward the process area 200 P 2 ) by the N2 gas ejected from the separation gas nozzle 241 . Thus, the O3 gas is evacuated from the evacuation port 262 via the evacuation area 200 E 2 at the gap between the circumferential edge of the rotation table 202 and the inner circumferential wall of the chamber 201 along with the N2 gas ejected from the center portion area 200 C.
[0208] Further, the BTBAS gas being ejected to a lower part of the first reaction gas nozzle 231 flows towards both the upstream and downstream sides relative to the rotation direction along the surface of the rotation table 202 . Such BTBAS gas can hardly flow into the lower part of the sector-shaped convex portion 204 or is forced back towards the second process area 200 P 1 . Thus, the BTBAS gas is evacuated from the evacuation port 261 via the evacuation area 200 E 1 at the gap between the circumferential edge of the rotation table 202 and the inner circumferential wall of the chamber 201 along with the N2 gas ejected from the center portion area 200 C. In each of the separation areas 200 D, reaction gases (BTBAS gas or O3 gas) flowing in the atmosphere are prevented from entering. However, the gas molecules adsorbed to the wafer W pass the separation area, that is, the lower part of the low ceiling surface 244 of the sector-shaped convex portion 204 , to thereby contribute to film deposition.
[0209] Further, because the separation gases are ejected from the center portion area 200 C to the circumferential edges of the rotation table 202 , even if the BTBAS gas of the first process area 200 P 1 (O3 gas of the second process area 200 P 2 ) attempt to enter the center portion area 200 C, the separation gases impede or force back the gases (even if the gases enter to some degree). Accordingly, the gases are prevented from flowing through the center portion area 200 C and entering the second process area 200 P 2 (first process area 200 P 1 ).
[0210] In the separation area 200 D because the circumferential edge parts of the sector-shaped convex portions 204 are bent downward and a gap between such bent portion 246 and an outer edge surface of the rotation table 202 is made narrow, gas can be substantially stopped from passing therethrough. Therefore, BTBAS gas of the first process area 200 P 1 (O3 gas of second process area 200 P 2 ) can be prevented from flowing into the second process area 200 P 2 (first process area 200 P 1 ) via the outer side of the rotation table 202 . Therefore, the atmospheres of the first and second process areas 200 P 1 , 200 P 2 are substantially completely separated by the two separation areas 200 D. Thus, BTBAS gas can be evacuated from the evacuation port 261 and O3 gas can be evacuated from the evacuation port 262 . As a result, even where both reaction gases (in this example, BTBAS gas and O3 gas) are in the atmosphere, the reaction gases do not mix above the wafer W.
[0211] In this example, because the lower part of the rotation table 202 is purged with N2 gas, BTBAS gas can be prevented from flowing into the area where O3 gas is supplied.
[0212] Hence, because the first and second process areas 200 P 1 , 200 P 2 are connected to dedicated evacuation channels 263 a, 263 b via the evacuation areas 200 E 1 , 200 E 2 , each type of gas flowing into the first process area 200 P 1 and the first evacuation area 200 E 1 is evacuated from the first evacuation channel 263 a and each type of gas flowing into the second process area 200 P 2 and the second evacuation area 200 E 2 is evacuated from the second evacuation channel 263 b. Therefore, reaction gas supplied to a process area 200 P 1 , 200 P 2 on one side can be evacuated outside of the chamber 201 without mixing with reaction gas supplied to a process area 200 P 2 , 200 P 1 on the other side. Accordingly, after the film deposition process is finished, the transfer arm 210 sequentially transfers wafers W out of the vacuum chamber 201 in a manner opposite from the operation of transferring wafers W into the vacuum chamber 201 .
[0213] An example of process parameters preferable in the film deposition apparatus according to this embodiment is listed below.
rotational speed of the rotation table 202 : 1-500 rpm (in the case of the wafer W having a diameter of 300 mm) pressure in the chamber 201 : 1067 Pa (8 Torr) wafer temperature: 350° C. flow rate of BTBAS gas: 100 sccm flow rate of O3 gas: 10000 sccm flow rate of N2 gas from the separation gas nozzles 241 , 242 : 20000 sccm flow rate of N2 gas from the separation gas supplying pipe 251 : 5000 sccm the number of rotations of the rotation table 202 : 600 rotations (depending on the film thickness required)
[0222] With the above-described embodiment of the present invention, the following effects can be attained. In this embodiment, there is provided a vacuum chamber 201 having a rotation table 202 includes a first process area 200 P 1 to which a first reaction gas of BTBAS gas is supplied and a second process area 200 P 2 in which a second reaction gas of O3 is supplied. Further, the first and second process areas 200 P 1 , 200 P 2 are separated from each other in a rotation direction of the rotation table 202 . Further, separation areas 200 D are interposed between the first and second process areas 200 P 1 , 200 P 2 for supplying separation gas between the first and second process areas 200 P 1 , 200 P 2 from separation gas supplying parts 241 , 242 . A thin film deposition process is performed by rotating the rotation table 202 having plural wafers W arranged in a rotation direction and layering plural silicon oxide layers of reaction products with first and second reaction gases of BTBAS gas and O3 gas. Evacuation is performed with an evacuation port 261 of a first evacuation channel 263 a corresponding to the first process area 200 P 1 and an evacuation port 262 of a second evacuation channel 263 b corresponding to the second process area 200 P 2 . The evacuation system (evacuation channels 263 a, 263 b; pressure adjusting parts 265 a, 265 b; evacuation pumps 264 a, 264 b ) of each of the process areas 200 P 1 , 200 P 2 is independent from the other. Accordingly, in performing the thin film deposition process, BTBAS gas and O3 gas do not mix in the evacuation systems. Therefore, the possibility of reaction products being generated in the evacuation systems is extremely low.
[0223] Further, by providing low ceiling planes on both sides of the separation nozzle 241 , 242 relative to the rotation direction, each reaction gas can be prevented from entering the separation areas 200 D. Further, by ejecting separation gases from the center portion area 200 C (partitioned by the rotation center part of the rotation table 202 and the chamber 201 ) to the circumferential edges of the rotation table 202 and diffusing the separation gas on both sides of the separation area, the separation gas ejected from the rotation center part and the reaction gases can be evacuated via the gaps between the circumferential edges of the rotation table 202 and the inner peripheral wall of the chamber 201 . Thereby, different reaction gases can be prevented from being mixed, satisfactory film deposition can be performed, and generation of particles can be prevented. The present invention may be applied to a case of placing a single wafer W on the rotation table 202 .
[0224] With the film deposition apparatus according to an embodiment of the present invention, a so-called ALD (or MLD) technique is performed by arranging plural wafers W on the rotation table 202 in a rotation direction of the rotation table 202 and then rotating the rotation table 202 for allowing the wafers W to pass the first and second process areas 200 P 1 and 200 P 2 in order. Therefore, compared to the above-described single-wafer deposition method, the film deposition apparatus requires no time for purging reaction gas and is able to perform film deposition with high throughput.
[0225] It is to be noted that the evacuation system of the chamber 201 is not limited to two systems. For example, the film deposition apparatus illustrated in FIG. 42 is provided with a third process area 200 P 3 by adding the convex portion 204 above the rotation table 202 . Accordingly, a third evacuation system (evacuation channel 263 c, third pressure adjusting part 265 c, vacuum pump 264 ) may be connected to the third process area 200 P 3 . In FIG. 41 , reference numeral 310 indicates a third reaction gas nozzle, reference numeral 410 indicates a separation gas nozzle, and reference numeral 260 indicates an evacuation port.
[0226] Further, the number of evacuation systems connected to each process area 200 P 1 , 200 P 2 is not limited to one system. For example, two or more evacuation systems may be connected to each process area 200 P 1 , 200 P 2 .
[0227] Further, the method of operating the evacuation system is not limited to adjusting the pressure in the pressure areas 200 P 1 , 200 P 2 corresponding to each evacuation system as described above. For example, a flow meter may be provided in each evacuation system. Thereby, the opening of the valves provided in the evacuation channels 263 a, 263 b can be adjusted so the amount of evacuation from each process area is a predetermined value. Further, the part used for adjusting pressure or the amount of evacuation is not limited to a valve. For example, pressure or amount of evacuation may be adjusted by changing the number of rotations of a mechanical booster pump of the vacuum pumps.
[0228] As for reaction gases that are used in the present invention other than those of the above-described embodiments of the present invention, there are dichlorosilane (DCS), hexachlorodisilane (HCD), Trimethyl Aluminum (TMA), tris(dimethyl amino)silane (3DMAS), tetrakis-ethyl-methyl-amino-zirconium (TEMAZr), tetrakis-ethyl-methyl-amino-hafnium (TEMHf), bis(tetra methyl heptandionate)strontium (Sr(THD) 2 ), (methyl-pentadionate)(bis-tetra-methyl-heptandionate)titanium (Ti(MPD) (THD)), monoamino-silane, or the like.
[0229] As illustrated in FIGS. 43A and 43B , in a case where a wafer W having a diameter of, for example, 300 mm is used as the target substrate, the first ceiling surface 244 that creates the thin space in both sides of the separation gas nozzle 241 ( 242 ) is preferred to have a width L equal to or greater than 50 mm in the rotation direction of the rotation table 202 at a portion where the center WO of the wafer W passes. In order to effectively prevent reaction gases from entering an area below the convex portion 204 from both sides of the convex portion 204 , it is necessary to reduce the distance between the first ceiling surface 244 and the rotation table 202 in a case where the width L is small. Further, in a case where a predetermined length is set to the distance between the first ceiling surface 244 and the rotation table 202 , the speed of the rotation table 202 becomes faster the farther away from the rotation center of the rotation table 202 . Therefore, the width L required for attaining a reaction gas impeding effect becomes greater the farther away from the rotation center. When the length L is less than 50 mm, the distance between the ceiling surface 244 and the rotation table 202 is to be made significantly small. Accordingly, in order to prevent the rotation table 202 or the wafer W from colliding with the ceiling surface 244 , it is necessary to reduce the vibration of the rotation table 202 as much as possible. Further, it becomes easier for reactions gases to enter the lower part of the convex portion 204 from upstream of the convex portion 204 as the number of rotations of the rotation table 202 increases. Thus, when the width L is less than 50 mm, it becomes necessary to reduce the number of rotations of the rotation table 202 which is rather disadvantageous in terms of production throughput. Therefore, it is preferable for the width L to be equal to or greater than 50 mm. Nevertheless, the effects of the present invention may still be attained where the length L is equal to or less than 50 mm. In other words, it is preferable for the width L to be 1/10-1/1 compared to the diameter of the wafer W, and more preferably about ⅙ or greater than the diameter of the wafer W. For the sake of convenience, the concave portion 224 is not illustrated in FIG. 43A .
[0230] Examples of the layout of the process areas 200 P 1 , 200 P 2 and the separation areas 200 D other than the above-described embodiments of the present invention are described below. FIG. 44 illustrates an example where the second reaction nozzle 232 is positioned upstream from the transfer opening 215 with respect to the rotation direction of the rotation table 202 . The same effect as the above-described embodiments of the present invention can be attained even with this layout.
[0231] In this embodiment, as illustrated in FIG. 45 , in addition to providing low ceiling surfaces (first ceiling surfaces) 244 on both sides of the separation gas nozzle 241 ( 242 ) for forming narrow gaps, low ceiling surfaces are also provided on both sides of the reaction gas nozzle 231 ( 232 ), so that the ceiling surfaces are formed to be continuous. In other words, even in a case where the convex portion 204 is provided to the entire area facing the rotation table 202 , the same effect can be attained except at the areas other than the areas where the separation gas nozzle 241 ( 242 ) and the reaction gas nozzle 231 ( 232 ) are provided. From a different standpoint, this configuration has the first ceiling surfaces 244 on both sides of the separation gas nozzle 241 ( 242 ) extending to the reaction gas nozzle 231 ( 232 ). In this case, although the separation gas diffusing to both sides of the separation nozzle 241 ( 242 ) and separation gas diffusing to both sides of the reaction gas nozzle 231 ( 232 ) merge at a lower part of the convex portion 204 (narrow gap), the gases are evacuated from the evacuation port 261 ( 262 ) positioned between the separation gas nozzle 242 ( 241 ) and the reaction gas nozzle 231 ( 232 ).
[0232] In the above embodiments, the rotation shaft 222 for rotating the rotation table 202 is located in the center portion of the chamber 201 . In the above-described embodiment of the present invention, the space between the core portion of the rotation table 202 and the upper surface of the chamber 201 is purged with the separation gas. However, the chamber 201 may be configured as illustrated in FIG. 46 . In the film deposition apparatus of FIG. 46 , the bottom portion 214 of the center area of the chamber 201 includes a housing space 280 of a driving portion and a concave portion 280 a formed on the upper surface of the center portion of the chamber 201 . A pillar 281 is placed between the bottom surface of the housing space 280 and the upper surface of the concave part 280 a at the center portion of the chamber 201 for preventing the first reaction gas (BTBAS) ejected from the first reaction gas nozzle 231 and the second reaction gas (O3) ejected from the second reaction gas nozzle 232 from being mixed through the center portion of the chamber 201 .
[0233] In addition, a rotation sleeve 282 is provided so that the rotation sleeve 282 coaxially surrounds the pillar 281 . A ring-shape rotation table 202 is provided along the rotation sleeve 282 . Further, a driving gear portion 284 , which is driven by a motor 283 , is provided in the housing space 280 . The rotation sleeve 282 is rotated by the driving gear portion 284 via a gear portion 285 formed on the outer surface of the rotation sleeve 282 . Reference numerals 286 , 287 , and 288 indicate bearings. A purge gas supplying pipe 274 is connected to a bottom part of the housing space 280 , so that a purge gas is supplied into the housing space 280 . Another purge gas supplying pipe 275 is connected to an upper part of the housing space 280 , so that a purge gas is supplied between a side surface of the concave portion 280 a and an upper edge part of the rotation sleeve 282 . Although opening parts for supplying the purge gas to the space between the side surface of the concave portion 280 a and the upper edge part of the rotation sleeve 282 are illustrated in a manner provided on two areas (one on the left and one on the right) in FIG. 46 , the number of the opening parts (purge gas supplying port) may be determined so that the purge gas from the BTBAS gas and the O3 gas in the vicinity of the rotation sleeve 282 can be prevented from being mixed.
[0234] In the embodiment illustrated in FIG. 46 , a space between the side wall of the concave portion 280 a and the upper end portion of the rotation sleeve 282 corresponds to the ejection hole for ejecting the separation gas. Thus, in this embodiment, the ejection hole, the rotation sleeve 282 , and the pillar 281 constitute the center portion area provided at a center part of the chamber 201 .
[0235] The film deposition apparatus according to embodiments of the present invention may be integrated into a wafer process apparatus, an example of which is schematically illustrated in FIG. 47 . The wafer process apparatus includes an atmospheric transfer chamber 292 in which a transfer arm 293 is provided, load lock chambers (preparation chambers) 294 , 295 whose atmosphere is changeable between vacuum and atmospheric pressure, a vacuum transfer chamber 296 in which two transfer arms 297 are provided, and film deposition apparatuses 298 , 299 according to embodiments of the present invention. In addition, the wafer process apparatus includes cassette stages (not shown) on which a wafer cassette 291 such as a Front Opening Unified Pod (FOUP) is placed. The wafer cassette 291 is brought onto one of the cassette stages, and connected to a transfer in/out port provided between the cassette stage and the atmospheric transfer chamber 292 . Then, a lid of the wafer cassette (FOUP) 291 is opened by an opening/closing mechanism (not shown) and the wafer is taken out from the wafer cassette 291 by the transfer arm 293 . Next, the wafer is transferred to the load lock chamber 294 ( 295 ). After the load lock chamber 294 ( 295 ) is evacuated, the wafer in the load lock chamber 294 ( 295 ) is transferred further to one of the film deposition apparatuses 298 , 299 through the vacuum transfer chamber 296 by the transfer arm 297 a ( 297 b ). In the film deposition apparatus 298 ( 299 ), a film is deposited on the wafer in such a manner as described above. Because the wafer process apparatus has two film deposition apparatuses 298 , 299 that can house five wafers at a time, the ALD (or MLD) mode deposition can be performed at high throughput.
[0236] Further, the present invention is not limited to these embodiments, but variations and modifications may be made without departing from the scope of the present invention.
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There is disclosed a film deposition apparatus and a film deposition method for depositing a film on a substrate by carrying out cycles of supplying in turn at least two source gases to the substrate in order to form a layer of a reaction product, and a computer readable storage medium storing a computer program for causing the film deposition apparatus to carry out the film deposition method.
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BACKGROUND
[0001] The present invention relates generally to semiconductor device manufacturing processes and, more particularly, to a structure and method of reducing electromigration cracking and extrusion effects in semiconductor devices.
[0002] Integrated circuits are typically fabricated with multiple levels of patterned metallization lines, electrically separated from one another by interlayer dielectrics containing vias at selected locations to provide electrical connections between levels of the patterned metallization lines. As these integrated circuits are scaled to smaller dimensions in a continual effort to provide increased density and performance (e.g., by increasing device speed and providing greater circuit functionality within a given area chip), the interconnect linewidth dimension becomes increasingly narrow, which in turn renders them more susceptible to deleterious effects such as electromigration.
[0003] Electromigration is a term referring to the phenomenon of mass transport of metallic atoms (e.g., copper or aluminum) which make up the interconnect material, as a result of unidirectional or DC electrical current conduction therethrough. More specifically, the electron current collides with the metal ions, thereby pushing them in the direction of current travel. Over an extended period of time, the accumulation of metal at the anode end of the interconnect material significantly increases the local mechanical stress in the system. This in turn and may lead to delamination, cracking, and even metal extrusion from the metal wire, thereby causing an electrical short to adjacent interconnects. Electromigration becomes increasingly more significant in integrated circuit design, as relative current densities through metallization lines continue to increase as the linewidth dimensions shrink.
[0004] For example, FIG. 1 illustrates a scanning electron micrograph (SEM) cross-sectional image of a test structure 100 taken near the anode end of a failed interconnect line 102 included therein, as a result of electromigration stress. The current carrying interconnect line 102 is disposed between the adjacent “extrusion monitor” lines 104 a, 104 b, that do not carry current. As indicated above, there are two phenomena associated with the illustrated electromigration fail. First, a metal/cap layer interface is delaminated by the high stress, with the delamination spanning across the gap between adjacent wire 104 b. Second, metal extrusion of line 102 occurs and reaches the adjacent wire 104 a, causing an electrical short.
[0005] Although electromigration-induced extrusion failure is not particularly prevalent in previous technologies using silicon dioxide (SiO 2 ) and dense SiCOH (carbon doped oxide) as dielectric materials (and was generally treated as irrelevant since extrusion typically occurs long after an initial electromigration failure, defined by 20% resistance increase), this phenomenon has been more frequently observed during the evaluation of advanced technologies using ultra low-K dielectrics. A low-k dielectric material is one in which the relative dielectric constant is less than 4, while an ultra lo-k dielectric is one in which the relative dielectric constant is less than 3. Accordingly, it would be desirable to be able to minimize the adverse impacts of extrusion/delamination related damage associated with the electromigration phenomenon.
SUMMARY
[0006] The foregoing discussed drawbacks and deficiencies of the prior art are overcome or alleviated, in an exemplary embodiment, by a structure for reducing electromigration cracking and extrusion effects in semiconductor devices, including a first metal line formed in a first dielectric layer; a cap layer formed over the first metal line and first dielectric layer; a second dielectric layer formed over the cap layer; and a void formed in the second dielectric layer, stopping on the cap layer, wherein the void is located in a manner so as to isolate structural damage due to electromigration effects of the first metal line, the effects including one or more of extrusions of metal material from the first metal line and cracks from delamination of the cap layer with respect to the first dielectric layer.
[0007] In another embodiment, a semiconductor device structure includes a first wiring level, the first wiring level comprising a first metal line formed in a first dielectric layer, and a second metal line formed in the first dielectric layer, adjacent the first metal line; a first cap layer formed over the first wiring level; and a second wiring level formed over the first cap layer, the second wiring level comprising a second dielectric layer, a void formed in the second dielectric layer, stopping on the cap layer, and sealing dielectric material formed over the second cap layer, the sealing dielectric material configured to pinch off upper portions of the void while maintaining lower portions of the void; wherein the void is located in a manner so as to isolate structural damage due to electromigration effects of the first metal line, the effects including one or more of extrusions of metal material from the first metal line and cracks from delamination of the first cap layer with respect to the first dielectric layer.
[0008] In another embodiment, a method of reducing electromigration cracking and extrusion effects in semiconductor devices includes forming a first metal line in a first dielectric layer; forming a cap layer over the first metal line and first dielectric layer; forming a second dielectric layer over the cap layer; and forming a void formed in the second dielectric layer, stopping on the cap layer, wherein the void is located in a manner so as to isolate structural damage due to electromigration effects of the first metal line, the effects including one or more of extrusions of metal material from the first metal line and cracks from delamination of the cap layer with respect to the first dielectric layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Referring to the exemplary drawings wherein like elements are numbered alike in the several Figures:
[0010] FIG. 1 is a scanning electron micrograph (SEM) cross-sectional image of a test structure taken near the anode end of a failed interconnect line, as a result of electromigration stress;
[0011] FIG. 2( a ) is a cross-sectional view of a structure for reducing electromigration cracking and extrusion effects in semiconductor devices, in accordance with an embodiment of the invention;
[0012] FIG. 2( b ) illustrates the operation of the structure of FIG. 2( a ), with respect to containment of an electromigration induced extrusion and delamination defect;
[0013] FIG. 3 is a top view of the structure of FIG. 2( a ); and
[0014] FIGS. 4( a ) through 4 ( d ) are a sequence of cross-sectional views illustrating an exemplary process flow for forming the structure of FIG. 2( a ), in accordance with a further embodiment of the invention.
DETAILED DESCRIPTION
[0015] Disclosed herein is a structure and method of reducing electromigration cracking and extrusion effects in semiconductor devices. Briefly stated, a small opening is intentionally formed within an insulating dielectric layer between interconnects (specifically, near the anode region of the interconnects), which serves as a local crack stop to avoid crack propagation, as well as a reservoir to accommodate metal extrusion induced by electromigration. In so doing, any such extrusions are contained within the gap and thus prevented from creating shorts to adjacent interconnect lines. Further, any delamination/cracking at the anode end of the interconnect metal is contained at the gap, and prevented from being spread any further into the dielectric material.
[0016] Referring now to FIG. 2( a ), there is shown a cross-sectional view of a semiconductor device 200 , including a structure for reducing electromigration cracking and extrusion effects in semiconductor devices, in accordance with an embodiment of the invention. As shown therein, a first dielectric layer 202 (e.g., SiO 2 , SiCOH, low-K material, etc.) has metal interconnect lines 204 a, 204 b formed therein, representing a lower wiring level. The interconnect lines 204 a, 204 b include a suitable semiconductor metal wiring material such as, for example, aluminum, copper, gold, silver and alloys thereof, and is also surrounded on the bottom and sides thereof with one or more diffusion barrier layers (e.g., TaN, Ta, TiN, Ti, Ru, RuTa, etc.). The interconnect lines 204 a, 204 b, and first dielectric layer are further covered with a dielectric cap material 208 (e.g., Si 3 N 4 , SiC, SiCN, SiCH, etc.). To this point, the semiconductor structure 200 is formed in accordance with processing techniques known in the art.
[0017] In the example illustrated, only the interconnect line 204 a is assumed to be susceptible to electromigration induced damage (i.e., conducts current in a single direction, where the anode end of the line 204 a is shown in the figure). A second dielectric layer 210 is formed over the cap layer 208 , representing an upper wiring level. For purposes of simplicity, no interconnect lines are depicted in the second dielectric layer 210 , although it will be appreciated that such lines may be formed in that layer. Because line 204 a in the first dielectric layer 202 is susceptible to electromigration induced extrusions and cracking, a void (gap) 212 is intentionally formed within dielectric layer 210 around the anode end of line 204 a, the void 212 landing on top of the cap layer 208 . At least a portion of the void 212 is located between interconnect 204 a and adjacent interconnect 204 b.
[0018] As discussed in further detail herein, the void 212 may be lined with an optional liner/pore-sealing material 214 once the void 212 has been initially patterned after an upper level wiring cap layer 216 is formed over dielectric 210 . Then, a sealing dielectric material 218 is used to pinch off the upper portions of the void 212 before additional layers are formed in accordance with existing processes of record.
[0019] FIG. 2( b ) illustrates the operation of the structure of FIG. 2( a ), with respect to containment of an electromigration induced extrusion and delamination defect. As is shown, electromigration-induced extrusion 220 is depicted in the anode region of interconnect 204 a, extending in the direction of adjacent interconnect wire 204 b. However, the metal extrusion 220 is contained within the left portion of the void 212 shown in FIG. 2( b ) and does not short to the adjacent 204 b. Moreover, a delamination 222 of the interconnect metal and cap layer 208 is also confined by the right portion of the void 212 around the stressed wire 204 a and does not propagate further into any adjacent wires within the first dielectric layer 202 .
[0020] Referring now to FIG. 3 , there is shown a top view of the exemplary structure of FIG. 2( a ). In the example depicted, the void 212 is formed locally around the ends of the interconnect structure 204 a where extrusions occur, so as minimize space restrictions. For ease of illustration, the cap layer 208 is not depicted in FIG. 3 . In addition, FIG. 3 also illustrates the formation of vias 224 formed above (or below) the interconnect 204 a, for connection to upper (or lower) wiring levels. In the event that it is known ahead of time which end of the line 204 a is the anode end, then the void 212 can be even further localized to that specific end. Alternatively, the void could 212 also be formed on the cap layer (not shown in FIG. 3) above the interconnect line 204 a in a manner so as to surround the interconnect line 204 a.
[0021] Finally, FIGS. 4( a ) through 4 ( d ) are a sequence of cross-sectional views illustrating an exemplary process flow for forming the structure of FIG. 2( a ), in accordance with a further embodiment of the invention. In FIG. 4( a ), the lower wiring level (dielectric layer 202 , interconnect lines 204 a, 204 b, diffusion barrier 206 and cap layer 208 ) is formed, followed by the upper wiring level (dielectric layer 210 , associated metal lines (not shown) and cap layer 216 ). The dielectric layer 210 in the upper metal level may be the same material as the dielectric layer 202 in the lower wiring level and can be applied, for example, by chemical vapor deposition (CVD) or a spin-on technique. Then, in FIG. 4( b ), the void 212 around the anode end of the interconnect 204 a is patterned in the dielectric layer through lithography and etching process, landing on the cap layer 208 .
[0022] As then shown in FIG. 4( c ), an optional pore-sealing liner material 214 is deposited over the upper wiring level and the sidewalls and bottom of the void 212 . The pore-sealing liner material 214 may be desirable where the dielectric layer 210 is a porous material, such as porous SiCOH, for example. The pore-sealing liner material 214 may include the same material as used for the metal line diffusion barrier 206 (e.g., TaN, TiN, etc.) or could also be an oxide material. In any case, the sealing dielectric material 218 is then deposited in FIG. 4( d ) in order to pinch off the upper portions of the voids 212 . The sealing dielectric material 218 is deposited in a manner that maintains the integrity of the bottom of the voids 212 (i.e., does not completely fill the voids 212 with dielectric material). One suitable deposition method in this regard is through chemical vapor deposition (CVD).
[0023] While the invention has been described with reference to a preferred embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
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A structure for reducing electromigration cracking and extrusion effects in semiconductor devices includes a first metal line formed in a first dielectric layer; a cap layer formed over the first metal line and first dielectric layer; a second dielectric layer formed over the cap layer; and a void formed in the second dielectric layer, stopping on the cap layer, wherein the void is located in a manner so as to isolate structural damage due to electromigration effects of the first metal line, the effects including one or more of extrusions of metal material from the first metal line and cracks from delamination of the cap layer with respect to the first dielectric layer.
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FIELD OF THE INVENTION
The present invention relates to electronic countermeasures for protecting an aircraft against enemy missile attacks and, more particularly, to an airborne RF decoy that deceives a radar-based missile to track it instead of tracking the aircraft.
BACKGROUND OF THE INVENTION
Electronic countermeasures (ECM) are a subsection of electronic warfare (EW) which includes any sort of electrical or electronic device designed to deceive radar, sonar, or other detection systems. Electronic countermeasures may be used both offensively and defensively in any method to deny targeting information to an enemy. For example, ECM may cause the detecting radar system to falsely “identify” many separate targets or make the real target appear and disappear or move about randomly. ECM is used effectively to protect aircraft from guided missiles. Most air forces use them to protect their aircraft from attack.
Offensive ECM often takes the form of jamming. Defensive ECM includes using chaff and flares against incoming missiles, as well as soids (floating flares that are effective only in the terminal phase of missiles with infrared signature seeker heads), blip enhancement and jamming of missile terminal homers. When employed effectively ECM can keep aircraft from being tracked by search radars, surface-to-air missiles and air-to-air missiles.
Electronic counter-countermeasures (ECCM) describe a variety of practices which attempt to reduce or eliminate the effect of ECM on electronic sensors aboard vehicles, ships and aircraft and weapons such as missiles. ECCM is also referred to as Electronic Protective Measures (EPM), chiefly in Europe.
ECM is practiced by nearly all military units—land, sea or air. Aircraft are the primary weapons in the ECM battle because they can “see” a larger patch of earth than a sea or land-based unit. When employed effectively ECM can keep aircraft from being tracked by search radars, surface-to-air missiles and air-to-air missiles.
Modern radar-based threat systems with advanced Electronic Counter-Counter Measures capabilities are immune to existing on-board ECM techniques and pose a real threat to airborne platforms. Several methods for off-board protecting means had been suggested in the past. U.S. Pat. No. 5,333,814 describes a towed body aimed to intercept or collide with incoming threats but without any ECM capability. U.S. Pat. No. 6,492,931 describes an expendable decoy that operates off-board but is dependent on the equipment residing in the protected platform. This decoy is not a stand-alone jammer that can work autonomously against multiple targets and it poses major limitations on the flight envelope of the platform after the launching. Other towed decoy jammers are also known to act in close dependence with the protected platform, both electrically and mechanically. These types of decoy also limit the aircraft maneuvers and lowers the efficiency of other protective measures.
U.S. Pat. No. 6,429,800 deals with a true off-board expendable jammer. However, this decoy has no “receive” capability and/or any independent recognition of the enemy threats. It has no Digital Radio Frequency Memory (DRFM)-based equipment that can optimize the deceiving technique, nor any updating mechanism. It has no mechanical and aerodynamical detailed design. The spatial coverage and the frequency coverage are not explicitly described, thus the efficiency against multiple type threats arising from all directions is not proved.
SUMMARY OF THE INVENTION
The present invention provides an airborne Radio Frequency (RF) decoy that answers to the modern threats which overcomes the above mentioned limitations with full off-board and stand alone capabilities. The goal of the airborne RF decoy of the invention is to “pull/steal” the tracking of the missile and/or radar away from the protected airborne platform and towards the off-board decoy. The decoy thus causes the enemy attacking missile to explode at a sufficiently large distance from the protected airborne platform.
The airborne RF decoy of the invention can cope with multiple threats coming from any direction. The decoy does not require intimate knowledge of the technical details of the threats, thus providing a robust ECM solution.
The airborne RF decoy of the invention is an expendable, stand-alone, off-board Electronic Counter-Measure (ECM) system aimed to provide airborne platforms with protection against multiple radar-based threats including Air-to-Air (AA) and Surface-to-Air (SAM) missiles both active and semi-active ones. The airborne RF decoy is a stand-alone system that includes a receiver, a transmitter, a digital RF memory (DRFM), a power source and one or more omnidirectional EW antennas, all of which operate dependently of the equipment residing in the protected platform itself.
The airborne RF decoy has the mechanical outline of standard chaff and flare decoys and is safely ejected from any platform by pyrotechnic elements. It is compatible with all existing industry dispensers so that no structural or aerodynamical changes are required to the airborne RF decoy, and the operational deployment process is straight forward, that is, identical to the process of ejecting a chaff or a flare.
The basic concept of operation of the airborne RF decoy of the invention uses a robust technique to deceive enemy radar-based threats as follows: immediately after its ejection from the protected airborne platform, the airborne RF decoy activates an energy source, stabilizes its path, acquires illuminating signals and analyzes threat parameters. Then the decoy alters the received signals to generate an authentic false target and transmits a deceiving signal towards the radar threat. The radar threats locks on the decoy and follow its path. Thus the threat course is diverted from the protected airborne platform and a large miss distance of the attacking missile (tens to hundreds of meters) is assured.
The airborne RF decoy of the invention operates in accordance with a Pre-Flight-Data (PFD) file which defines the most probable threat in the arena. The pre-flight-data file is loaded prior to the mission to each specific decoy by an external data loader via a dedicated connector that is embedded in the decoy. The decoy's data file can be updated by several methods: before ejection by a wire/proximity link, after ejection via a medium-range wireless link, or via a long-range wireless link with the protected airborne platform.
Once a long-range wireless link to the protected airborne platform is established, it can be used for synchronization purposes with the equipment on-board the platform. For example, it can be used for time synchronization with the platform's radars and self protection suit by blanking the airborne RF decoy at specific time intervals. Alternatively, it can be used for cooperative jamming by blinking between deceiving signals coming from the platform and from the decoy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the protected aircraft ejecting 3 airborne RF decoys, from 3 separate dispensers, towards different directions.
FIG. 2 shows the ejected airborne RF decoy attracting an approaching enemy missile towards itself.
FIG. 3 illustrates the principle of synchronization/blinking between airborne RF decoy radars of the invention and a protected airborne platform's radars, via a long range wireless link.
FIG. 4 illustrates a physical layout of an airborne RF decoy of the invention.
FIG. 5 is an electrical block diagram of an airborne RF decoy of the invention.
FIG. 6 depicts a layout of the RF board inside an airborne RF decoy of the invention.
FIG. 7 depicts a top view and a bottom view layout of the digital board inside an airborne RF decoy of the invention.
FIG. 8 is a schematic diagram of the battery inside an airborne RF decoy of the invention.
FIG. 9 is a schematic diagram of EW antennas of the airborne RF decoy of the invention.
DETAILED DESCRIPTION OF THE INVENTION
In the following detailed description of various embodiments, reference is made to the accompanying drawings that form a part thereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
The present invention relates to an airborne RF decoy adapted for protecting an airborne platform against multiple enemy radar-based threats, said airborne RF decoy comprising:
(i) means for receiving a plurality of radar signals from one or more directions; (ii) means for storing said plurality of radar signals; (iii) means for analyzing said plurality of radar signals to identify threat parameters; (iv) means for altering said plurality of radar signals in order to deceive said multiple enemy radar-based threats; (v) means for transmitting the altered radar signals; and (vi) an independent power supply source.
The airborne RF decoy of the invention is an independent, stand-alone, autonomous flying body. It is not attached to the protected airborne platform by a cable or similar attaching mechanisms, rather the airborne RF decoy flies on its own means, using its own power supply source.
The term “airborne platform” as used herein includes fighter aircraft, wide-body transport aircraft, wide-body passenger aircraft, unmanned air vehicles (UAV), unmanned combat aircraft (UCA) and balloons.
The installation of the airborne RF decoy of the invention on board of a typical airborne platform is shown in FIG. 1 . The protected airborne platform 10 may eject at any instant one or several airborne RF decoys 20 . The magazine of RF decoys 30 can be installed at various locations on the airborne platform 10 and the ejection can be directed towards any desired direction. FIG. 1 shows 3 ejected airborne RF decoys 20 , one in the direction of the flight, a second one ejected sideways and the third airborne RF decoys 20 ejected at the rear of the aircraft, against the flight direction of the airborne platform 10 . In one embodiment of the present invention, the ejection is done using pyrotechnic dispensers. A clear and fluent jettison process ensures the safety of the ejection in any flight positions and speeds of the protected platform. The airborne RF decoy 20 can be ejected by an automatic alert sent either from the on-board Missile Warning System (MWS) or from the Radar Warning Receiver (RWS) or by a manual command of the aircrew.
The basic concept of operation uses a generic, robust and coherent technique to deceive the radar-based threats as follows. Once the airborne RF decoy 20 is activated it emits radio frequency (RF) signals that are very similar and coherent to radar signals that are scattered from the protected airborne platform 10 and produce coherent false targets to the enemy radar. FIG. 2 shows a radar-based threat, which is usually a radar-based missile 40 or a similar flying body, detecting the deceiving signal coming from the airborne RF decoy 20 . The radar-based missile 40 interprets the deceiving signal as a legitimate target and “locks” its attack trajectory 50 towards the airborne RF decoy 20 . Since the airborne RF decoy's 20 trajectory 60 differs from the trajectory of the protected airborne platform 10 , the radar-based missile 40 hits or flies by (and explodes) the airborne RF decoy 20 at a distance of typically several hundreds of meters from the protected airborne platform 10 .
Enemy radar-base threats usually include: air-to-air missiles 40 (both semi active and active), air-to-air fire-control radars (FCR), surface-to-air missiles (SAM) 40 , surface-to-air radars or any combination thereof.
The airborne RF decoy 20 emits its deceiving signals within a broad spatial coverage both in azimuth and in elevation. Thus, it can effectively deceive threats coming from all directions.
In one embodiment of the present invention, the airborne RF decoy 20 includes means to control the distance between said airborne RF decoy 20 and said airborne platform 10 . For example, the use of rocket propulsion mounted inside the airborne RF decoy 20 can control the relative distance between the protected airborne platform 10 and the airborne RF decoy 20 . In some cases the airborne RF decoy 20 can move in a higher speed than the airborne platform 10 thus operating in front of the airborne platform 10 rather than at its back. The distance between the airborne RF decoy 20 and the airborne platform 10 ranges from tens to hundreds of meters in both range and altitude.
The airborne RF decoy 20 opens a large distance of tens to hundreds of meters from the protected airborne platform 10 both in range and in altitude thus any hit of a radar-based threat 40 occurs at a safe range from the airborne platform 10 .
The airborne RF decoy 20 can handle multiple radar-based threats 40 simultaneously coming from many directions, thanks to one or more omnidirectional antennas embedded inside the airborne RF decoy 20 . The omnidirectional antenna can receive a plurality of radar signals. The omnidirectional antenna or antennas are implemented without any erection mechanisms or moving parts. In order to improve the probability of deception, the airborne RF decoy 20 operates in accordance with a Pre Flight Data (PFD) file that defines the most probable radar-based threats 40 in the arena. The PFD file is loaded prior to the mission to each individual airborne RF decoy 20 by an external data loader via a dedicated connector.
In another embodiment of the present invention, the airborne RF decoy 20 includes means to communicate with the airborne platform 10 . These communication means (links) include: (i) a wire or proximity link; (ii) a short-range wireless link; (iii) a long-range wireless link; or any combination thereof. The proximity link serves a distance of a few centimeters. The short-range link serves typically a distance of a few meters, while the long-range link can operate in a distance of hundreds of meters.
The airborne RF decoy 20 PFD can be updated by several methods: the first method is before ejection by a wire or proximity link; the second method is after ejection via a medium-range wireless link; and the third method is via a long-range wireless link with the protected platform. FIG. 3 illustrates the airborne RF decoy 20 including a wireless radio link 70 which transmits/receives with the protected airborne platform's 10 wireless radio link 80 via a line of sight communication channel 90 . This long-range communication link provides updating instructions to the airborne RF decoy 20 concerning the actual parameters of the threat such as frequency, bandwidth, transmit power, Pulse Repetition Frequency (PRF), Doppler shift, low frequency modulation (LFM) of the RF signal and others, to ensure the optimal generation of the false target transmission. It should be emphasized that although the airborne RF decoy 20 has the capability to receive and analyze the incoming signal threats, its deception is efficient against all various types of radar-guided threats (active and semi-active) without the need for intimate knowledge of their technical details. This inherent efficiency steams from the physical spatial separation between the airborne RF decoy 20 and the protected airborne platform 10 .
In one embodiment of the present invention, the RF decoy 20 includes means for minimizing interferences between the airborne RF decoy 20 and the on-board equipment of the airborne platform 10 .
In a further embodiment of the present invention, said means for minimizing interferences include either blanking of said airborne RF decoy 20 so it does not interfere with on-board equipment of the airborne platform 10 when operation of said on-board equipment has higher priority; or blanking on-board systems of the airborne platform 10 that interfere with said airborne RF decoy 20 when operation of said airborne RF decoy 20 has higher priority.
Once a long-range wireless link to the protected airborne platform 10 is established it can be used for cooperative jamming with the EW/ECM equipment on-board the airborne platform 10 . For example, it enables generation of combined synchronized blinking between deceiving signals coming from the airborne platform 10 and from the airborne RF decoy 20 . In addition, it can be used for time synchronization by blanking some systems, thus minimizing interferences between the airborne RF decoy 20 and the on-board equipment. FIG. 3 depicts a possible time sharing between the transmissions from the airborne RF decoy 20 and the transmissions from the radar installed on board of the protected airborne platform 10 .
The spatial orientation of the airborne RF decoy 20 , after the ejection from the airborne platform 10 , can be stabilized in the roll plane, in one embodiment, or it is not stabilized in the roll plane, in another embodiment, making use of different embedded antenna polarizations. In most cases the radar-based threats 40 operate in a linear polarization. If the airborne RF decoy 20 is stabilized in the roll plane, its antenna is linear polarized. If the airborne RF decoy 20 is not stabilized in the roll plane, its antenna is circular polarized and has radiation capabilities in all roll angles.
In one embodiment of the present invention, said embedded antenna takes the form of a small monopole, an array of two monopoles or an array of three conformal radiating elements when said antenna operates in a linear polarization.
In another embodiment of the present invention, said embedded antenna takes the form of helical antennas when said antenna operates in a circular polarization.
The aerodynamical stabilization of the airborne RF decoy 20 is achieved by vertical and horizontal wings that are opened automatically after the ejection from the airborne platform 10 . In order to improve the stabilization process, the wings are opened in two steps: a mechanical opening of the wings immediately after ejection followed by a pyrotechnic mechanism, which brings the wings to their final position. In a further embodiment of the present invention, a gas propulsion mechanism can be added to the airborne RF decoy 20 , which enables to accelerate its path and contributes to its flight stability.
FIG. 4 shows the physical layout of the airborne RF decoy 20 . An electric battery 110 provides the current and the voltage required for the entire period of operation of the airborne RF decoy 20 . The preferred battery 110 is a thermal battery 110 that can be maintenance-free for a period of at least 10-15 years, being rechargeable or replaceable afterwards. The thermal battery 110 is activated at the instance of the ejection in by an appropriate mechanism 120 . Alternatively, an alkaline battery 110 may be used instead of the thermal battery 110 .
The power supply unit 130 is a DC to DC converter which accepts the voltage of the battery (at a nominal value of 12V) and transforms it to several regulated voltages (such as 8V, 5V, 3.3V, 1.8V, 1.2V etc). The RF board 140 includes a microwave low noise receiver operating at a direct conversion technology, a microwave high power transmitter, a frequency synthesizer and a T/R switch (or an isolator). The RF board 140 is connected to an EW antenna 160 mounted on the external envelope of the airborne RF decoy 20 and to a digital board 170 which includes a DRFM with a real time coherent memory and digital control components.
The entire body 100 of the airborne RF decoy 20 is stabilized during its flight by horizontal and vertical stabilization wings 180 and possibly by an additional propulsion mechanism.
In one embodiment of the present invention, said airborne RF decoy 20 has the external form of a standard chaff decoy or a standard flare decoy. The ejection of the airborne RF decoy 20 can thus be performed by pyrotechnic dispensing mechanisms that are identical to those of standard chaff or flare decoys. The airborne RF decoy 20 can thus be ejected from the airborne platform 10 via a standard housing of chaff or flare dispensers. The RF decoy 20 can thus be implemented in a Mobile Jettison Unit (MJU) such as an MJU-7 envelope (1×2×8 inches) or an MJU-10 envelope (2×2×8 inches).
In another embodiment of the present invention, the airborne RF decoy 20 is ejected via a dedicated housing.
In addition, the physical layout of the airborne RF decoy 20 may include a standard connector for software loading and tests 200 , a wire/proximity communication module 210 , a medium range communication module 220 and a long-range communication module 70 .
The electrical block diagram sketched in FIG. 5 illustrates the functionality of the airborne RF decoy 20 . The EW antenna 160 receives the RF signals coming from the radar-based threat. The T/R (transmit/receive) switch or the circulator 300 transfer the received signals to a low noise amplifier (receiver) 310 and then the signal is converted into Base band and processed in the Digital RF Memory (DRFM) 320 . The specific EW technique generates a false target, and transfers it to the High Power Transmitter 330 . This false target is then transmitted to the air through the same EW antenna 160 . Additional items of wire/proximity module 210 , medium range module 220 , long-range module 70 and software loading/test connector 200 , all connected to the digital board 170 , are also shown in FIG. 5 . The airborne RF decoy 20 also includes an independent power supply source 340 . The power supply source 340 can be a standard alkaline battery or a thermal battery that is activated during the ejection of the airborne RF decoy 20 from the airborne platform 10 .
In another aspect of the present invention, a method is provided for protecting an airborne platform 10 against multiple enemy radar-based threats by deceiving an enemy to follow a false target, comprising:
(i) ejecting an airborne RF decoy 20 from the airborne platform 10 ;
(ii) receiving in the airborne RF decoy 20 a plurality of radar signals from one or more directions;
(iii) storing said plurality of radar signals on the airborne RF decoy 20 ;
(iv) analyzing said plurality of radar signals by the airborne RF decoy 20 to identify threat parameters;
(v) altering said plurality of radar signals by said airborne RF decoy 20 in order to deceive said multiple radar-based threats; and
(vi) transmitting the altered radar signals by said airborne RF decoy 20 .
The airborne RF decoy 20 starts its life cycle by “listening” to said plurality of radar signals in order to identify possible radar-based threats, and acquire the specific active radar-based threats. The plurality of radar signals can be stored in DRFM memory 320 or in any memory with similar functionality. Once the existence of the radar-based threat is confirmed, the airborne RF decoy 20 starts to transmit the deceiving signals.
In one embodiment of the present invention, the airborne RF decoy 20 stops transmitting altered signals from time to time and instead analyzes the received radar signals to confirm if each enemy radar-based threat still exists or if the previously identified threat parameters have changed. Threat parameters include frequency, bandwidth, transmission power, pulse repetition frequency (PRF), Doppler shift, low frequency modulation (LMF) of the RF signal, or any combination thereof. The DRFM 320 shown in FIG. 5 updates the false targets accordingly.
The layout of the RF board 140 is further detailed in FIG. 6 . The Receive channel includes a switch or a circulator 300 , a low noise amplifier 410 , a band pass filter 430 and a balanced mixer 450 . The transmit channel includes a balanced mixer 451 , a phase shifter 440 , a band pass filter 431 , a high power amplifier 420 and the same switch or circulator 300 . The synthesizer unit 460 generates accurate frequency carriers that down convert the signals into low frequency. The RF signals are sampled by I/Q modulator 470 and then transferred unto the DRFM 320 .
FIG. 7 shows the layout of the Digital Board 170 including digital processors, analog to digital converters, digital to analog converters, memory units and programmable gate arrays. The real time software that controls the mission of the airborne RF decoy 20 resides in this Digital Board 170 .
In yet another embodiment of the present invention, the airborne RF decoy 20 enters automatically into an “end of life” mode with self-destruction capability and complete memory erase for sensitive components that carry data.
FIG. 8 shows the layout of a thermal battery 110 including the activation mechanism 120 and the connecting positive port 510 , negative port 520 , and ground port 530 .
In yet another embodiment of the present invention, more than one EW antenna 160 is installed in the airborne RF decoy 20 . FIG. 9 illustrates a schematic diagram with up to three EW antennas 160 . In this case, one EW antenna 160 serves to receive signals while the other one serves to transmit signals. It is even possible to include a third antenna 160 mounted in the front of the airborne RF decoy 20 . All the antennas 160 are fed by the RF Board 140 and receive/transmit to the air in a broad spatial coverage (up to 360 degrees in azimuth and at least 90 degrees in elevation). The antenna 160 can be built to operate in a linear polarization while the airborne RF decoy's 20 body 100 is stabilized in the roll plane or in a circular polarization while the airborne RF decoy's 20 body 100 is not stabilized in the roll plane. Thus the antenna 160 enables the airborne RF decoy 20 to operate against multiple enemy radar-based missiles 40 that approach the airborne platform 10 from different directions. The implementation of the antenna can take the form of a small monopole 610 , an array of two monopoles, an conformal array of three radiating elements 620 or a helix structure. The monopole antenna 610 is connected to an antenna feed 600 . An electric layer 630 connects all the antennas 160 . All antenna 160 implementations are mounted on the airborne RF decoy 20 without any erection mechanisms or moving parts. The broad coverage is achieved by a unique combination of scattering by the metallic airborne RF decoy's 20 body 100 itself, such that the body 100 acts as an antenna.
Although the invention has been described in detail, nevertheless changes and modifications, which do not depart from the teachings of the present invention, will be evident to those skilled in the art. Such changes and modifications are deemed to come within the purview of the present invention and the appended claims.
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An expendable, stand-alone, off-board Electronic Counter-Measure system, airborne RF decoy aimed to provide airborne platforms with protection against multiple radar-based threats including Air-to-Air and Surface-to-Air missiles both active and semi-active ones. The airborne RF decoy has the mechanical outline of standard chaff and flare decoys and is safely ejected from any platform by pyrotechnic elements. The airborne RF decoy deceives enemy radar-based threats as follows: immediately after its ejection from the protected airborne platform, the decoy activates an energy source, stabilizes its path, acquires illuminating signals and analyzes threat parameters. Then the decoy alters the received signals to generate an authentic false target and transmits a deceiving signal towards the radar threat. The radar threats locks on the decoy and follow its path. Thus the threat course is diverted from the protected airborne platform and a large miss distance of the attacking missile (tens to hundreds of meters) is assured.
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RELATED APPLICATIONS
[0001] This application is related to and claims priority to U.S. Provisional Patent Application Ser. No. 61/783,845 filed on Mar. 14, 2013 entitled “Multi-Layer Fiber Coating.” The subject matter disclosed in that provisional application is hereby expressly incorporated into the present application in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to multi-layer fiber coatings, and particularly to multi-layer fiber coatings for ceramic fiber applications.
BACKGROUND
[0003] Economical and environmental concerns, i.e. improving efficiency and reducing emissions, are driving forces behind the ever increasing demand for higher gas turbine inlet temperatures. A limitation to the efficiency and emissions of many gas turbine engines is the temperature capability of hot section components such as blades, vanes, blade tracks, and combustor liners. Technology improvements in cooling, materials, and coatings are required to achieve higher inlet temperatures. As the temperature capability of Ni-based superalloys has approached their intrinsic limit, further improvements in their temperature capability have become increasingly difficult. Therefore, the emphasis in gas turbine materials development has shifted to thermal barrier coatings (TBC) and next generation high temperature materials, such as ceramic-based materials.
[0004] Silicon Carbide/Silicon Carbide (SiC/SiC) Ceramic Material Composite (CMC) materials are prime candidates to replace Ni-based superalloys for hot section structural components for next generation gas turbine engines. The key benefit of SiC/SiC CMC engine components is their excellent high temperature mechanical, physical, and chemical properties which allow gas turbine engines to operate at much higher temperatures than the current engines having superalloy components. SiC/SiC CMCs also provide the additional benefit of damage tolerance, which monolithic ceramics do not possess.
SUMMARY
[0005] The present disclosure includes a multi-layer fiber coatings for ceramic fiber applications.
[0006] An illustrative embodiment of the present disclosure provides a multi-layer fiber coating which comprises: a ceramic grade Nicalon preform; a silicon carbide coat applied over the fibers; wherein the silicon carbide coat has a thickness of about 1 μm; a boron nitride interface coat applied over the silicon carbide coat; wherein the boron nitride coat has a thickness of about 0.5 μm; a silicon carbide coat applied over the boron nitride coat; and wherein the silicon carbide has a thickness of about 2 μm.
[0007] In the above and other embodiments, the multi-layer fiber coating may further comprise: the Nicalon preform including about 36% fiber volume; the Nicalon preform being assembled in a tooling for chemical vapor infiltration; the silicon carbide coat having an effective fiber volume of about 39%; the Nicalon preform being cleaned using air at about 600 degrees C. to remove sizing char; the preform being completed with slurry and melt infiltration; the 1 μm of silicon carbide being applied by chemical vapor infiltration; the 2 μm of silicon carbide being applied by chemical vapor infiltration.
[0008] Another illustrative embodiment of the present disclosure provides a multi-layer fiber coating which comprises: a Tyranno Lox-M fiber coated in tow form with 1 μm of silicon carbide by a chemical vapor deposition process and about 1 μm of silicon nitride; a silicon doped boron nitride coat is applied over the about 1 μm of silicon nitride; and wherein the doped boron nitride coat has a thickness of 0.3 μm.
[0009] In the above and other embodiments, the multi-layer fiber coating may further comprise: the Tyranno Lox-M fiber in the tow being coated with silicon nitride of about 0.3 μm and silicon carbide of about 0.1 μm; the tow being processed with a silicon carbide slurry and binders to form a uni-directional tape; the tapes being laminated and shaped, then cured; and a resulting body that is infiltrated with silicon to complete the CMC component.
[0010] Another illustrative embodiment of the present disclosure provides a multi-layer fiber coating which comprises: a T-300 carbon fiber preform; a coat that is graded from PyC to SiC is applied over the T-300 carbon fiber preform; wherein the graded PyC to SiC coat has a thickness of about 1.5 μm; a silicon doped boron nitride interface coat is applied over the graded PyC to SiC coat; wherein the silicon doped boron nitride interface coat has a thickness of about 0.5 μm; and a silicon carbide coat of 2 μm is applied over the silicon doped boron nitride interface coat.
[0011] In the above and other embodiments, the multi-layer fiber coating may further comprise: the T-300 carbon fiber preform includes about 36% fiber volume; the T-300 carbon fiber preform is assembled in tooling for chemical vapor infiltration; a silicon nitride coat of about 0.2 μm being applied over the silicon carbide coat; the graded PyC to SiC coat being applied by chemical vapor infiltration; the silicon carbide coating of 2 μm being applied by chemical vapor infiltration; and the silicon nitride coat of 0.2 μm being applied by chemical vapor infiltration.
[0012] It should be appreciated that the present application discloses one or more of the features recited in the appended claims and/or the following features which alone or in any combination may comprise patentable subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a flow diagram showing a multi-layer process according to the present disclosure; and
[0014] FIG. 2 is an end view of ceramic fibers showing an “improved” multi-layer coating.
DETAILED DESCRIPTION
[0015] The present disclosure includes a fiber coating that incorporates at least one layer prior to the fiber interface coating to improve chemical compatibility of the fiber and interface coating. Illustratively, the first coating is bonded to the fiber and is followed by an interface coating and optionally additional coatings. The coating may be a slightly altered composition of the fiber or a totally different composition. The coating acts as barrier between incompatible elements.
[0016] The coating may also “heal” surface flaws on the fiber and to increase the effective fiber volume by increasing the diameter of the fiber. The coating may be uniform in composition and structure, graded intentionally to produce a better match between the fiber and the interface coating or consist of multiple thin layers prior to the interface coating. The coating may be followed by other functional coatings prior to the interface coating to improve structural performance or environmental resistance.
[0017] The coating may range from 0.01 μm to 2 μm, and may be deposited by chemical vapor deposition, physical vapor deposition (including directed vapor deposition) or other suitable means. The fiber in the composite may be carbon, ceramic (silicon carbide, alumina, aluminosilicate, SiNC etc.) or glass. The coating (or coating layers) may consist of elemental, binary or ternary compounds of the following elements: carbon, nitrogen, oxygen, silicon, germanium, boron, aluminum, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, nickel, scandium, yttrium, ytterbium and rhenium.
[0018] Illustratively, it may be desirable to tailor the coating composition and/or structure to produce a slightly lower modulus than the fiber to reduce stress in the coating layer and delay surface cracking.
[0019] A flow diagram depicting a process 2 of applying a barrier coating on a fiber is shown in FIG. 1 . The first step of process 2 is providing the fiber material, textile, or preform, for processing at 4 . Illustratively, the fiber surface may be prepared by cleaning it using high temperature air to remove sizing char at 6 . A barrier coating is then applied over the fiber at 8 . This barrier coating may be a silicon carbide coating applied by chemical vapor infiltration, for example. Over the barrier coating, the fiber interface coating is supplied at 10 . Such an interface coating may include boron nitride. A structural and protective coating 12 may be applied over interface coating 10 . The structural coating may be silicon carbide applied by chemical vapor infiltration. Optionally, additional fiber layers may be applied at 14 after the structural coating if not already done in step 1 of process 2 . Lastly, a CMC matrix may be completed with slurry and melt infiltration at 16 .
[0020] An end sectional view of fiber material 18 is shown in FIG. 2 . A barrier coating 20 such as that described with respect to step 8 in FIG. 1 is applied over top of fiber 18 . An interface coating 22 is applied over the barrier coating. Lastly, the structural protective layer coating 24 is applied on top pursuant step 12 of process 2 .
[0021] Advantages of this multi-layer coating may include: enabling use of lower cost fibers with oxygen sensitive interface coatings like boron nitride; reducing or eliminating damage to fiber surfaces during interface coating deposition (e.g. incompatibility of carbon and BN deposition); the additional layer providing an opportunity to manage thermal and mechanical incompatibilities between a fiber an subsequent coatings and additional oxidation resistance to the fiber; increasing ultimate strength resulting from surface defect reduction; and increasing creep strength if the fiber coating has higher creep capability than the fiber.
[0022] The following are non-limiting illustrative embodiments of a barrier coating:
Preform Based CMC
[0023] 1. A ceramic grade Nicalon preform constructed of 36% fiber volume and assembled in tooling for chemical vapor infiltration (CVI);
[0024] 2. the preform is cleaned using air at 600 degrees C. to remove sizing char from the fiber;
[0025] 3. the fiber is coated with 1 μm of silicon carbide (SiC) by CV, the effective fiber volume is now close to 39%;
[0026] 4. a boron nitride (BN) interface coating is then applied at 0.5 μm;
[0027] 5. a SiC coating of 2 μm is applied by CVI; and
[0028] 6. the CMC matrix is completed with slurry and melt infiltration.
[0029] It is notable that the interface coating remains functional as a result of limited, if any, interaction with oxygen in the fiber.
CMC Made with Pre-Coated Fiber
[0030] 1. Tyranno Lox-M fiber is coated in tow form with 1 μm of SiC by a chemical vapor deposition (CVD) process, and 1 μm of silicon nitride;
[0031] 2. a subsequent process applies a silicon doped boron nitride coating of 0.3 μm;
[0032] 3. the fiber in the tow is coated with silicon nitride of 0.3 μm and silicon carbide of 0.1 μm;
[0033] 4. the tow is processed with a SiC slurry and binders to form a tape;
[0034] 5. the tapes are laminated and shaped then cured; and
[0035] 6. the resulting body is infiltrated with silicon to complete the CMC component.
[0036] Again, the interface coating remains functional as a result of limited if any interaction with oxygen in the fiber.
Preform Based CMC II
[0037] 1. A T-300 carbon fiber preform is constructed of 36% fiber volume and assembled in tooling for CVI;
[0038] 2. the fiber is coated with a layer that is graded from PyC to SiC over 1.5 μm by CVI;
[0039] 3. a silicon doped boron nitride (BN) interface coating of 0.5 μm is applied;
[0040] 4. a SiC coating of 2 μm is then applied by CVI; [correct?]
[0041] 5. a silicon nitride coating of 0.2 μm is applied by CVI; and
[0042] 6. the CMC matrix is completed through slurry and melt infiltration.
[0043] The resulting composite has an interface coating with improved oxidation resistance compared to the typical PyC coating and the fiber remains undamaged from the BN deposition process.
[0044] While the disclosure has been described in this detailed description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been described and that changes and modifications that come within the spirit of the disclosure are desired to be protected.
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A multi-layer fiber coating is provided which, in an illustrative embodiment, includes: a ceramic grade Nicalon preform; a silicon carbide coat applied over the fibers; a boron nitride interface coat applied over the silicon carbide coat; wherein the boron nitride coat has a thickness of about 0.5 μm; a silicon carbide coat applied over the boron nitride coat; and wherein the silicon carbide has a thickness of about 2 μm.
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